Insect

Insects or Insecta (from Latin insectum) are hexapod invertebrates and the largest
group within the arthropod phylum. Definitions and circumscriptions vary; usually, Insect
insects comprise a class within the Arthropoda. As used here, the term Insecta is Temporal range: 396–0 Ma
synonymous with Ectognatha. Insects have a chitinous exoskeleton, a three-part body PreЄ Є O S D C P T J K PgN
(head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of
Early Devonian[1] (but see text) – Present
antennae. Insects are the most diverse group of animals; they include more than a million
described species and represent more than half of all known living organisms.[2][3] The
total number of extant species is estimated at between six and ten million;[2][4][5]
potentially over 90% of the animal life forms on Earth are insects.[5][6] Insects may be
found in nearly all environments, although only a small number of species reside in the
oceans, which are dominated by another arthropod group, crustaceans.

Nearly all insects hatch from eggs. Insect growth is constrained by the inelastic
exoskeleton and development involves a series of molts. The immature stages often differ
from the adults in structure, habit and habitat, and can include a passive pupal stage in
those groups that undergo four-stage metamorphosis. Insects that undergo three-stage
metamorphosis lack a pupal stage and adults develop through a series of nymphal
stages.[7] The higher level relationship of the insects is unclear. Fossilized insects of Clockwise from top left: dance fly
enormous size have been found from the Paleozoic Era, including giant dragonflies with
(Empis livida), long-nosed weevil
wingspans of 55 to 70 cm (22 to 28 in). The most diverse insect groups appear to have
coevolved with flowering plants. (Rhinotia hemistictus), mole cricket
(Gryllotalpa brachyptera), German
Adult insects typically move about by walking, flying, or sometimes swimming. As it
wasp (Vespula germanica), emperor
allows for rapid yet stable movement, many insects adopt a tripedal gait in which they
walk with their legs touching the ground in alternating triangles, composed of the front & gum moth (Opodiphthera eucalypti),
rear on one side with the middle on the other side. Insects are the only invertebrates to assassin bug (Harpactorinae)
have evolved flight, and all flying insects derive from one common ancestor. Many insects 0:00 MENU
spend at least part of their lives under water, with larval adaptations that include gills,
and some adult insects are aquatic and have adaptations for swimming. Some species, A chorus of several Magicicada
such as water striders, are capable of walking on the surface of water. Insects are mostly species
solitary, but some, such as certain bees, ants and termites, are social and live in large,
well-organized colonies. Some insects, such as earwigs, show maternal care, guarding Scientific classification
their eggs and young. Insects can communicate with each other in a variety of ways. Male Kingdom: Animalia
moths can sense the pheromones of female moths over great distances. Other species
communicate with sounds: crickets stridulate, or rub their wings together, to attract a Phylum: Arthropoda
mate and repel other males. Lampyrid beetles communicate with light. Clade: Pancrustacea
Humans regard certain insects as pests, and attempt to control them using insecticides, Subphylum: Hexapoda
and a host of other techniques. Some insects damage crops by feeding on sap, leaves,
Class: Insecta
fruits, or wood. Some species are parasitic, and may vector diseases. Some insects
perform complex ecological roles; blow-flies, for example, help consume carrion but also Linnaeus, 1758
spread diseases. Insect pollinators are essential to the life cycle of many flowering plant Subgroups
species on which most organisms, including humans, are at least partly dependent;
without them, the terrestrial portion of the biosphere would be devastated.[8] Many See text.
insects are considered ecologically beneficial as predators and a few provide direct
economic benefit. Silkworms produce silk and honey bees produce honey and both have
been domesticated by humans. Insects are consumed as food in 80% of the world's Synonyms
nations, by people in roughly 3000 ethnic groups.[9][10] Human activities also have
effects on insect biodiversity. Ectognatha
Entomida

Contents
Etymology
Definitions
Phylogeny and evolution
Phylogeny
Taxonomy
Evolutionary relationships
Diversity
Morphology and physiology
 External
Segmentation
Exoskeleton
Internal
Nervous system
Digestive system
Foregut
Midgut
Hindgut
Excretory system
Reproductive system
Respiratory system
Circulatory system
Reproduction and development
Metamorphosis
Incomplete metamorphosis
Complete metamorphosis
Senses and communication
Light production and vision
Sound production and hearing
Chemical communication
Social behavior
Care of young
Locomotion
Flight
Walking
Use in robotics
Swimming
Ecology
Defense and predation
Pollination
Parasitism
Relationship to humans
As pests
In beneficial roles
In research
As food
As feed
In other products
As pets
In culture
See also
References
Bibliography
Further reading
External links

Etymology
The word "insect" comes from the Latin word insectum, meaning "with a notched or divided body", or literally "cut into", from
the neuter singular perfect passive participle of insectare, "to cut into, to cut up", from in- "into" and secare "to cut";[11] because
insects appear "cut into" three sections. A calque of Greek ἔντοµον [éntomon], "cut into sections", Pliny the Elder introduced
the Latin designation as a loan-translation of the Greek word ἔντοµος (éntomos) or "insect" (as in entomology), which was
Aristotle's term for this class of life, also in reference to their "notched" bodies. "Insect" first appears documented in English in
1601 in Holland's translation of Pliny. Translations of Aristotle's term also form the usual word for "insect" in Welsh (trychfil,
from trychu "to cut" and mil, "animal"), Serbo-Croatian (zareznik, from rezati, "to cut"), Russian (насекомое nasekomoje,
from seč'/-sekat', "to cut"), etc.[11][12]
Definitions
The precise definition of the taxon Insecta and the equivalent English name "insect" varies; three alternative definitions are
shown in the table.

Definition of Insecta

Group Alternative definitions

Collembola (springtails)
Entognatha
Protura (coneheads)
(paraphyletic) Apterygota
Diplura (two-pronged bristletails) Insecta sensu lato (wingless hexapods)
=Hexapoda (paraphyletic)
Archaeognatha (jumping bristletails)
Insecta sensu stricto
Zygentoma (silverfish)
=Ectognatha
Pterygota (winged insects) Insecta sensu strictissimo

In the broadest circumscription, Insecta sensu lato consists of all hexapods.[13][14] Traditionally, insects defined in this way
were divided into "Apterygota" (the first five groups in the table)—the wingless insects—and Pterygota—the winged insects.[15]
However, modern phylogenetic studies have shown that "Apterygota" is not monophyletic,[16] and so does not form a good
taxon. A narrower circumscription restricts insects to those hexapods with external mouthparts, and comprises only the last
three groups in the table. In this sense, Insecta sensu stricto is equivalent to Ectognatha.[13][16] In the narrowest
circumscription, insects are restricted to hexapods that are either winged or descended from winged ancestors. Insecta sensu
strictissimo is then equivalent to Pterygota.[17] For the purposes of this article, the middle definition is used; insects consist of
two wingless taxa, Archaeognatha (jumping bristletails) and Zygentoma (silverfish), plus the winged or secondarily wingless
Pterygota.

Phylogeny and evolution

The evolutionary relationship of insects to other animal groups remains unclear.

Although traditionally grouped with millipedes and centipedes—possibly on the basis of convergent adaptations to
terrestrialisation[19]—evidence has emerged favoring closer evolutionary ties with crustaceans. In the Pancrustacea theory,
insects, together with Entognatha, Remipedia, and Cephalocarida, make up a natural clade labeled Miracrustacea.[20]

Insects form a single clade, closely related to crustaceans and myriapods.[21]

Other terrestrial arthropods, such as centipedes, millipedes, scorpions, and spiders, are sometimes confused with insects since
their body plans can appear similar, sharing (as do all arthropods) a jointed exoskeleton. However, upon closer examination,
their features differ significantly; most noticeably, they do not have the six-legged characteristic of adult insects.[22]

The higher-level phylogeny of the arthropods continues to be a matter of debate and research. In 2008, researchers at Tufts
University uncovered what they believe is the world's oldest known full-body impression of a primitive flying insect, a 300-
million-year-old specimen from the Carboniferous period.[23] The oldest definitive insect fossil is the Devonian Rhyniognatha
hirsti, from the 396-million-year-old Rhynie chert. It may have superficially resembled a modern-day silverfish insect. This
species already possessed dicondylic mandibles (two articulations in the mandible), a feature associated with winged insects,
suggesting that wings may already have evolved at this time. Thus, the first insects probably appeared earlier, in the Silurian
period.[1][24]

Four super radiations of insects have occurred: beetles (from about 300 million years ago), flies (from about 250 million years
ago), moths and wasps (both from about 150 million years ago).[25] These four groups account for the majority of described
species. The flies and moths along with the fleas evolved from the Mecoptera.

The origins of insect flight remain obscure, since the earliest winged insects currently known appear to have been capable fliers.
Some extinct insects had an additional pair of winglets attaching to the first segment of the thorax, for a total of three pairs. As
of 2009, no evidence suggests the insects were a particularly successful group of animals before they evolved to have wings.[26]

Late Carboniferous and Early Permian insect orders include both extant groups, their stem groups,[27] and a number of
Paleozoic groups, now extinct. During this era, some giant dragonfly-like forms reached wingspans of 55 to 70 cm (22 to 28 in),
making them far larger than any living insect. This gigantism may have been due to higher atmospheric oxygen levels that
allowed increased respiratory efficiency relative to today. The lack of flying vertebrates could have been another factor. Most
extinct orders of insects developed during the Permian period that began around 270 million years ago. Many of the early
groups became extinct during the Permian-Triassic extinction event, the largest mass extinction in the history of the Earth,
around 252 million years ago.[28]
The remarkably successful Hymenoptera appeared as long as 146 million years ago in the
Cretaceous period, but achieved their wide diversity more recently in the Cenozoic era,
which began 66 million years ago. A number of highly successful insect groups evolved in Hexapoda (Insecta,
conjunction with flowering plants, a powerful illustration of coevolution.[29] Collembola, Diplura,
Protura)
Many modern insect genera developed during the Cenozoic. Insects from this period on
are often found preserved in amber, often in perfect condition. The body plan, or
Crustacea (crabs,
morphology, of such specimens is thus easily compared with modern species. The study
shrimp, isopods, etc.)
of fossilized insects is called paleoentomology.
Myriapoda

Pauropoda
Phylogeny

Diplopoda (millipedes)

Chilopoda (centipedes)

Symphyla
Chelicerata

Arachnida (spiders,
scorpions, mites, ticks,
etc.)

Eurypterida (sea
scorpions: extinct)

Xiphosura (horseshoe
crabs)

Pycnogonida (sea
spiders)

†Trilobites (extinct)

A phylogenetic tree of the

arthropods and related groups[18]

Evolution has produced enormous

variety in insects. Pictured are some
possible shapes of antennae.

Insect classification
Insecta Monocondylia
 Archaeognatha (Hump-backed/jumping bristletails)

Dicondylia
Zygentoma (silverfish, firebrats, fishmoths)

Paranotalia
†Carbotriplurida

Pterygota Hydropalaeoptera
†Bojophlebiidae

Odonatoptera (Dragonflies)

Panephemeroptera (Mayflies)

Neoptera Polyneoptera Haplocercata

Zoraptera (Angel insects)

Dermaptera (earwigs)

Plecoptera (stoneflies)

Orthoptera (grasshoppers, cri

Dictyoptera
Mantodea (pray

Blattodea (cock

Xenonomia
(Notopterodea)

Eukinolabia

Eumetabola Acercaria
Psocodea (Book lice, barkice &

Hemiptera (true bugs)

Thysanoptera (Thrips)

Holometabola Hymenopterida
Hymenoptera

Aparaglossata Neuropteriforma

Panorpida
​
A cladogram based on the works of Sroka, Staniczek & Bechly 2014,[30] Prokop et al. 2017[31] & Wipfler et al. 2019.[32]

Taxonomy

Traditional morphology-based or appearance-based systematics have usually given the Hexapoda the rank of superclass,[34]:180
and identified four groups within it: insects (Ectognatha), springtails (Collembola), Protura, and Diplura, the latter three being
grouped together as the Entognatha on the basis of internalized mouth parts. Supraordinal relationships have undergone
numerous changes with the advent of methods based on evolutionary history and genetic data. A recent theory is that the
Hexapoda are polyphyletic (where the last common ancestor was not a member of the group), with the entognath classes
having separate evolutionary histories from the Insecta.[35] Many of the traditional appearance-based taxa have been shown to
be paraphyletic, so rather than using ranks like subclass, superorder, and infraorder, it has proved better to use monophyletic
groupings (in which the last common ancestor is a member of the group). The following represents the best-supported
monophyletic groupings for the Insecta.

Insects can be divided into two groups historically treated as subclasses: wingless insects, known as Apterygota, and winged
insects, known as Pterygota. The Apterygota consist of the primitively wingless order of the silverfish (Zygentoma).
Archaeognatha make up the Monocondylia based on the shape of their mandibles, while Zygentoma and Pterygota are grouped
together as Dicondylia. The Zygentoma themselves possibly are not monophyletic, with the family Lepidotrichidae being a
sister group to the Dicondylia (Pterygota and the remaining Zygentoma).[36][37]

Paleoptera and Neoptera are the winged orders of insects differentiated by the presence of hardened body parts called sclerites,
and in the Neoptera, muscles that allow their wings to fold flatly over the abdomen. Neoptera can further be divided into
incomplete metamorphosis-based (Polyneoptera and Paraneoptera) and complete metamorphosis-based groups. It has proved
difficult to clarify the relationships between the orders in Polyneoptera because of constant new findings calling for revision of
the taxa. For example, the Paraneoptera have turned out to be more closely related to the Endopterygota than to the rest of the
Exopterygota. The recent molecular finding that the traditional louse orders Mallophaga and Anoplura are derived from within
Psocoptera has led to the new taxon Psocodea.[38] Phasmatodea and Embiidina have been suggested to form the
Eukinolabia.[39] Mantodea, Blattodea, and Isoptera are thought to form a monophyletic group termed Dictyoptera.[40]

The Exopterygota likely are paraphyletic in regard to the Endopterygota. Matters that have incurred controversy include
Strepsiptera and Diptera grouped together as Halteria based on a reduction of one of the wing pairs—a position not well-
supported in the entomological community.[41] The Neuropterida are often lumped or split on the whims of the taxonomist.
Fleas are now thought to be closely related to boreid mecopterans.[42] Many questions remain in the basal relationships among
endopterygote orders, particularly the Hymenoptera.

The study of the classification or taxonomy of any insect is called systematic entomology. If one works with a more specific
order or even a family, the term may also be made specific to that order or family, for example systematic dipterology.

Evolutionary relationships
Insects are prey for a variety of organisms, including terrestrial vertebrates. The earliest vertebrates on land existed 400 million
years ago and were large amphibious piscivores. Through gradual evolutionary change, insectivory was the next diet type to
evolve.[43]
Insects were among the earliest terrestrial herbivores and acted as major selection
agents on plants.[29] Plants evolved chemical defenses against this herbivory and Classification
the insects, in turn, evolved mechanisms to deal with plant toxins. Many insects Monocondylia
make use of these toxins to protect themselves from their predators. Such insects -Archaeognatha - 470
often advertise their toxicity using warning colors.[44] This successful evolutionary
Apterygota
pattern has also been used by mimics. Over time, this has led to complex groups of
-Zygentoma<200
coevolved species. Conversely, some interactions between plants and insects, like
-Monura
pollination, are beneficial to both organisms. Coevolution has led to the
development of very specific mutualisms in such systems. Paleoptera
-Ephemeroptera-
2,500–<3,000
Diversity -Odonata- 6,500
Neoptera
Estimates on the total number of insect species, or those within specific orders, -Blattodea –
often vary considerably. Globally, averages of these estimates suggest there are 3,684–4,000
around 1.5 million beetle species and 5.5 million insect species, with about 1 million -Coleoptera –
insect species currently found and described.[45] 360,000–400,000
-Dermaptera –
Between 950,000–1,000,000 of all described species are insects, so over 50% of all 1,816

described eukaryotes (1.8 million) are insects (see illustration). With only 950,000 -Diptera –
152,956
known non-insects, if the actual number of insects is 5.5 million, they may
-Embioptera –
represent over 80% of the total. As only about 20,000 new species of all organisms 200–300
are described each year, most insect species may remain undescribed, unless the -Hemiptera –
rate of species descriptions greatly increases. Of the 24 orders of insects, four 50,000–80,000
dominate in terms of numbers of described species; at least 670,000 identified -Hymenoptera –
species belong to Coleoptera, Diptera, Hymenoptera or Lepidoptera. 115,000
-Lepidoptera –
As of 2017, at least 66 insect species extinctions had been recorded in the previous 174,250

500 years, which generally occurred on oceanic islands.[47] Declines in insect Insecta -Mantodea –
2,200
abundance have been attributed to artificial lighting,[48] land use changes such as Dicondylia
-Mecoptera – 481
urbanization or agricultural use,[49][50] pesticide use,[51] and invasive species.[52]
Pterygota -Megaloptera –
Studies summarized in a 2019 review suggested a large proportion of insect species 250–300
are threatened with extinction in the 21st century. [53] Though ecologist Manu -Neuroptera –
Sanders notes the 2019 review was biased by mostly excluding data showing 5,000
increases or stability in insect population, with the studies limited to specific -Notoptera – 30
geographic areas and specific groups of species.[54] A larger meta-study published -Orthoptera –
24,380
in 2020, analyzing data from 166 long-term surveys, suggested that populations of
-Phasmatodea –
terrestrial insects are decreasing by about 9% per decade.[55][56] Claims of pending 2,500–3,300
mass insect extinctions or "insect apocalypse" based on a subset of these studies -Phthiraptera –
have been popularized in news reports, but often extrapolate beyond the study data 3,000–3,200
or hyperbolize study findings.[57] Other areas have shown increases in some insect -Plecoptera –
species, although trends in most regions are currently unknown. It is difficult to 2,274

assess long-term trends in insect abundance or diversity because historical -Psocoptera –

5,500
measurements are generally not known for many species. Robust data to assess at-
-Raphidioptera –
risk areas or species is especially lacking for arctic and tropical regions and a 210
majority of the southern hemisphere. [57]
-Siphonaptera –
2,525
-Strepsiptera –
596
-Thysanoptera –
5,000
-Trichoptera –
12,627
-Zoraptera – 28

Cladogram of living insect groups,[33]

with numbers of species in each group.[5]
The Apterygota, Palaeoptera, and
Exopterygota are possibly paraphyletic
groups.
 Estimates of total extant insect species[45]

Order Estimated total species

Archaeognatha 513

Zygentoma 560

Ephemeroptera 3,240

Odonata 5,899

Orthoptera 23,855

Neuroptera 5,868

Phasmatodea 3,014

Embioptera 463
A pie chart of described eukaryote
Grylloblattodea 34 species, showing just over half of
these to be insects
Mantophasmatodea 20

Plecoptera 3,743

Dermaptera 1,978

Zoraptera 37

Mantodea 2,400

Blattodea 7,314

Psocoptera 5,720

Phthiraptera 5,102

Thysanoptera 5,864
Insects with population trends
Hemiptera 103,590 documented by the International
Hymenoptera 116,861 Union for Conservation of Nature, for
orders Collembola, Hymenoptera,
Strepsiptera 609 Lepidoptera, Odonata, and
Coleoptera 386,500 Orthoptera. Of 203 insect species
that had such documented
Megaloptera 354 population trends in 2013, 33% were
Raphidioptera 254 in decline.[46]

Trichoptera 14,391

Lepidoptera 157,338

Diptera 155,477

Siphonaptera 2,075

Mecoptera 757

Morphology and physiology

External
Insects have segmented bodies supported by exoskeletons, the hard outer covering made mostly of chitin. The segments of the
body are organized into three distinctive but interconnected units, or tagmata: a head, a thorax and an abdomen.[58] The head
supports a pair of sensory antennae, a pair of compound eyes, zero to three simple eyes (or ocelli) and three sets of variously
modified appendages that form the mouthparts. The thorax is made up of three segments: the prothorax, mesothorax and the
metathorax. Each thoracic segment supports one pair of legs. The meso- and metathoracic segments may each have a pair of
wings, depending on the insect. The abdomen consists of eleven segments, though in a few species of insects, these segments
may be fused together or reduced in size. The abdomen also contains most of the digestive, respiratory, excretory and
reproductive internal structures.[34]:22–48 Considerable variation and many adaptations in the body parts of insects occur,
especially wings, legs, antenna and mouthparts.

Segmentation
The head is enclosed in a hard, heavily sclerotized, unsegmented, exoskeletal head capsule, or epicranium, which contains most
of the sensing organs, including the antennae, ocellus or eyes, and the mouthparts. Of all the insect orders, Orthoptera displays
the most features found in other insects, including the sutures and sclerites.[59] Here, the vertex, or the apex (dorsal region), is
situated between the compound eyes for insects with a hypognathous and opisthognathous head. In prognathous insects, the
vertex is not found between the compound eyes, but rather, where the ocelli are
normally. This is because the primary axis of the head is rotated 90° to become
parallel to the primary axis of the body. In some species, this region is modified
and assumes a different name.[59]:13

The thorax is a tagma composed of three sections, the prothorax, mesothorax

and the metathorax. The anterior segment, closest to the head, is the prothorax,
with the major features being the first pair of legs and the pronotum. The
middle segment is the mesothorax, with the major features being the second
pair of legs and the anterior wings. The third and most posterior segment,
abutting the abdomen, is the metathorax, which features the third pair of legs
and the posterior wings. Each segment is dilineated by an intersegmental
suture. Each segment has four basic regions. The dorsal surface is called the Insect morphology
tergum (or notum) to distinguish it from the abdominal terga.[34] The two A- Head B- Thorax C- Abdomen
1. antenna
lateral regions are called the pleura (singular: pleuron) and the ventral aspect is
2. ocelli (lower)
called the sternum. In turn, the notum of the prothorax is called the pronotum,
3. ocelli (upper)
the notum for the mesothorax is called the mesonotum and the notum for the
4. compound eye
metathorax is called the metanotum. Continuing with this logic, the mesopleura 5. brain (cerebral ganglia)
and metapleura, as well as the mesosternum and metasternum, are used.[59] 6. prothorax
7. dorsal blood vessel
The abdomen is the largest tagma of the insect, which typically consists of 11–12 8. tracheal tubes (trunk with spiracle)
segments and is less strongly sclerotized than the head or thorax. Each segment 9. mesothorax
of the abdomen is represented by a sclerotized tergum and sternum. Terga are 10. metathorax
separated from each other and from the adjacent sterna or pleura by 11. forewing
membranes. Spiracles are located in the pleural area. Variation of this ground 12. hindwing
plan includes the fusion of terga or terga and sterna to form continuous dorsal 13. mid-gut (stomach)
or ventral shields or a conical tube. Some insects bear a sclerite in the pleural 14. dorsal tube (Heart)
area called a laterotergite. Ventral sclerites are sometimes called laterosternites. 15. ovary
During the embryonic stage of many insects and the postembryonic stage of 16. hind-gut (intestine, rectum & anus)
primitive insects, 11 abdominal segments are present. In modern insects there is 17. anus
a tendency toward reduction in the number of the abdominal segments, but the 18. oviduct
primitive number of 11 is maintained during embryogenesis. Variation in 19. nerve chord (abdominal ganglia)
20. Malpighian tubes
abdominal segment number is considerable. If the Apterygota are considered to
21. tarsal pads
be indicative of the ground plan for pterygotes, confusion reigns: adult Protura
22. claws
have 12 segments, Collembola have 6. The orthopteran family Acrididae has 11
23. tarsus
segments, and a fossil specimen of Zoraptera has a 10-segmented abdomen.[59] 24. tibia
25. femur
26. trochanter
Exoskeleton
27. fore-gut (crop, gizzard)
28. thoracic ganglion
The insect outer skeleton, the cuticle, is made up of two layers: the epicuticle,
29. coxa
which is a thin and waxy water resistant outer layer and contains no chitin, and
30. salivary gland
a lower layer called the procuticle. The procuticle is chitinous and much thicker
31. subesophageal ganglion
than the epicuticle and has two layers: an outer layer known as the exocuticle 32. mouthparts
and an inner layer known as the endocuticle. The tough and flexible endocuticle
is built from numerous layers of fibrous chitin and proteins, criss-crossing each
other in a sandwich pattern, while the exocuticle is rigid and hardened.[34]:22–24 The exocuticle is greatly reduced in many
insects during their larval stages, e.g., caterpillars. It is also reduced in soft-bodied adult insects.

Insects are the only invertebrates to have developed active flight capability, and this has played an important role in their
success.[34]:186 Their flight muscles are able to contract multiple times for each single nerve impulse, allowing the wings to beat
faster than would ordinarily be possible.

Having their muscles attached to their exoskeletons is efficient and allows more muscle connections.

Internal

Nervous system

The nervous system of an insect can be divided into a brain and a ventral nerve cord. The head capsule is made up of six fused
segments, each with either a pair of ganglia, or a cluster of nerve cells outside of the brain. The first three pairs of ganglia are
fused into the brain, while the three following pairs are fused into a structure of three pairs of ganglia under the insect's
esophagus, called the subesophageal ganglion.[34]:57

The thoracic segments have one ganglion on each side, which are connected into a pair, one pair per segment. This
arrangement is also seen in the abdomen but only in the first eight segments. Many species of insects have reduced numbers of
ganglia due to fusion or reduction.[60] Some cockroaches have just six ganglia in the abdomen, whereas the wasp Vespa crabro
has only two in the thorax and three in the abdomen. Some insects, like the house fly Musca domestica, have all the body
ganglia fused into a single large thoracic ganglion.

At least a few insects have nociceptors, cells that detect and transmit signals responsible for the sensation of pain.[61] This was
discovered in 2003 by studying the variation in reactions of larvae of the common fruitfly Drosophila to the touch of a heated
probe and an unheated one. The larvae reacted to the touch of the heated probe with a stereotypical rolling behavior that was
not exhibited when the larvae were touched by the unheated probe.[62] Although nociception has been demonstrated in insects,
there is no consensus that insects feel pain consciously[63]

Insects are capable of learning.[64]

Digestive system

An insect uses its digestive system to extract nutrients and other substances from the food it consumes.[65] Most of this food is
ingested in the form of macromolecules and other complex substances like proteins, polysaccharides, fats and nucleic acids.
These macromolecules must be broken down by catabolic reactions into smaller molecules like amino acids and simple sugars
before being used by cells of the body for energy, growth, or reproduction. This break-down process is known as digestion.

There is extensive variation among different orders, life stages, and even castes in the digestive system of insects.[66] This is the
result of extreme adaptations to various lifestyles. The present description focus on a generalized composition of the digestive
system of an adult orthopteroid insect, which is considered basal to interpreting particularities of other groups.

The main structure of an insect's digestive system is a long enclosed tube called the alimentary canal, which runs lengthwise
through the body. The alimentary canal directs food unidirectionally from the mouth to the anus. It has three sections, each of
which performs a different process of digestion. In addition to the alimentary canal, insects also have paired salivary glands and
salivary reservoirs. These structures usually reside in the thorax, adjacent to the foregut.[34]:70–77 The salivary glands (element
30 in numbered diagram) in an insect's mouth produce saliva. The salivary ducts lead from the glands to the reservoirs and
then forward through the head to an opening called the salivarium, located behind the hypopharynx. By moving its mouthparts
(element 32 in numbered diagram) the insect can mix its food with saliva. The mixture of saliva and food then travels through
the salivary tubes into the mouth, where it begins to break down.[67][68] Some insects, like flies, have extra-oral digestion.
Insects using extra-oral digestion expel digestive enzymes onto their food to break it down. This strategy allows insects to
extract a significant proportion of the available nutrients from the food source.[69]:31 The gut is where almost all of insects'
digestion takes place. It can be divided into the foregut, midgut and hindgut.

Foregut

The first section of the alimentary canal is the foregut (element 27 in numbered
diagram), or stomodaeum. The foregut is lined with a cuticular lining made of chitin
and proteins as protection from tough food. The foregut includes the buccal cavity
(mouth), pharynx, esophagus and crop and proventriculus (any part may be highly
modified), which both store food and signify when to continue passing onward to the
midgut.[34]:70

Digestion starts in buccal cavity (mouth) as partially chewed food is broken down by
saliva from the salivary glands. As the salivary glands produce fluid and carbohydrate-
digesting enzymes (mostly amylases), strong muscles in the pharynx pump fluid into
the buccal cavity, lubricating the food like the salivarium does, and helping blood
feeders, and xylem and phloem feeders.

From there, the pharynx passes food to the esophagus, which could be just a simple
tube passing it on to the crop and proventriculus, and then onward to the midgut, as in
most insects. Alternately, the foregut may expand into a very enlarged crop and
proventriculus, or the crop could just be a diverticulum, or fluid-filled structure, as in Stylized diagram of insect digestive tract
some Diptera species.[69]:30–31 showing malpighian tubule, from an insect
of the order Orthoptera

Midgut

Once food leaves the crop, it passes to the midgut (element 13 in numbered diagram), also known as the mesenteron, where the
majority of digestion takes place. Microscopic projections from the midgut wall, called microvilli, increase the surface area of
the wall and allow more nutrients to be absorbed; they tend to be close to the origin of the midgut. In some insects, the role of
the microvilli and where they are located may vary. For example, specialized microvilli producing digestive enzymes may more
likely be near the end of the midgut, and absorption near the origin or beginning of the midgut.[69]:32

Hindgut
 In the hindgut (element 16 in numbered diagram), or proctodaeum, undigested food
particles are joined by uric acid to form fecal pellets. The rectum absorbs 90% of the
water in these fecal pellets, and the dry pellet is then eliminated through the anus
(element 17), completing the process of digestion. Envaginations at the anterior end of
the hindgut form the Malpighian tubules, which form the main excretory system of
insects.

Excretory system

Insects may have one to hundreds of Malpighian tubules (element 20). These tubules
remove nitrogenous wastes from the hemolymph of the insect and regulate osmotic
Bumblebee defecating. Note the balance. Wastes and solutes are emptied directly into the alimentary canal, at the
contraction of the abdomen to provide junction between the midgut and hindgut.[34]:71–72, 78–80
internal pressure

Reproductive system

The reproductive system of female insects consist of a pair of ovaries, accessory glands, one or more spermathecae, and ducts
connecting these parts. The ovaries are made up of a number of egg tubes, called ovarioles, which vary in size and number by
species. The number of eggs that the insect is able to make vary by the number of ovarioles with the rate that eggs can develop
being also influenced by ovariole design. Female insects are able make eggs, receive and store sperm, manipulate sperm from
different males, and lay eggs. Accessory glands or glandular parts of the oviducts produce a variety of substances for sperm
maintenance, transport and fertilization, as well as for protection of eggs. They can produce glue and protective substances for
coating eggs or tough coverings for a batch of eggs called oothecae. Spermathecae are tubes or sacs in which sperm can be
stored between the time of mating and the time an egg is fertilized.[59]:880

For males, the reproductive system is the testis, suspended in the body cavity by tracheae and the fat body. Most male insects
have a pair of testes, inside of which are sperm tubes or follicles that are enclosed within a membranous sac. The follicles
connect to the vas deferens by the vas efferens, and the two tubular vasa deferentia connect to a median ejaculatory duct that
leads to the outside. A portion of the vas deferens is often enlarged to form the seminal vesicle, which stores the sperm before
they are discharged into the female. The seminal vesicles have glandular linings that secrete nutrients for nourishment and
maintenance of the sperm. The ejaculatory duct is derived from an invagination of the epidermal cells during development and,
as a result, has a cuticular lining. The terminal portion of the ejaculatory duct may be sclerotized to form the intromittent
organ, the aedeagus. The remainder of the male reproductive system is derived from embryonic mesoderm, except for the germ
cells, or spermatogonia, which descend from the primordial pole cells very early during embryogenesis.[59]:885

Respiratory system

Insect respiration is accomplished without lungs. Instead, the insect respiratory system
uses a system of internal tubes and sacs through which gases either diffuse or are actively
pumped, delivering oxygen directly to tissues that need it via their trachea (element 8 in
numbered diagram). In most insects, air is taken in through openings on the sides of the
abdomen and thorax called spiracles.

The respiratory system is an important factor that limits the size of insects. As insects get
larger, this type of oxygen transport is less efficient and thus the heaviest insect currently
weighs less than 100 g. However, with increased atmospheric oxygen levels, as were
present in the late Paleozoic, larger insects were possible, such as dragonflies with
wingspans of more than two feet.[70]

There are many different patterns of gas exchange demonstrated by different groups of The tube-like heart (green) of the
mosquito Anopheles gambiae
insects. Gas exchange patterns in insects can range from continuous and diffusive
extends horizontally across the body,
ventilation, to discontinuous gas exchange.[34]:65–68 During continuous gas exchange, interlinked with the diamond-shaped
oxygen is taken in and carbon dioxide is released in a continuous cycle. In discontinuous wing muscles (also green) and
gas exchange, however, the insect takes in oxygen while it is active and small amounts of surrounded by pericardial cells (red).
carbon dioxide are released when the insect is at rest. [71] Diffusive ventilation is simply a Blue depicts cell nuclei.
form of continuous gas exchange that occurs by diffusion rather than physically taking in
the oxygen. Some species of insect that are submerged also have adaptations to aid in
respiration. As larvae, many insects have gills that can extract oxygen dissolved in water, while others need to rise to the water
surface to replenish air supplies, which may be held or trapped in special structures.[72][73]

Circulatory system

Because oxygen is delivered directly to tissues via tracheoles, the circulatory system is not used to carry oxygen, and is therefore
greatly reduced. The insect circulatory system is open; it has no veins or arteries, and instead consists of little more than a
single, perforated dorsal tube that pulses peristaltically. This dorsal blood vessel (element 14) is divided into two sections: the
heart and aorta. The dorsal blood vessel circulates the hemolymph, arthropods' fluid analog of blood, from the rear of the body
cavity forward.[34]:61–65[74] Hemolymph is composed of plasma in which hemocytes are suspended. Nutrients, hormones,
wastes, and other substances are transported throughout the insect body in the hemolymph. Hemocytes include many types of
cells that are important for immune responses, wound healing, and other functions. Hemolymph pressure may be increased by
muscle contractions or by swallowing air into the digestive system to aid in moulting.[75] Hemolymph is also a major part of the
open circulatory system of other arthropods, such as spiders and crustaceans.[76][77]

Reproduction and development

The majority of insects hatch from eggs. The fertilization and development takes place inside
the egg, enclosed by a shell (chorion) that consists of maternal tissue. In contrast to eggs of
other arthropods, most insect eggs are drought resistant. This is because inside the chorion
two additional membranes develop from embryonic tissue, the amnion and the serosa. This
serosa secretes a cuticle rich in chitin that protects the embryo against desiccation. In
Schizophora however the serosa does not develop, but these flies lay their eggs in damp
places, such as rotting matter.[78] Some species of insects, like the cockroach Blaptica dubia,
A pair of Simosyrphus as well as juvenile aphids and tsetse flies, are ovoviviparous. The eggs of ovoviviparous
grandicornis hoverflies mating in animals develop entirely inside the female, and then hatch immediately upon being laid.[7]
flight. Some other species, such as those in the genus of cockroaches known as Diploptera, are
viviparous, and thus gestate inside the mother and are born alive.[34]:129, 131, 134–135 Some
insects, like parasitic wasps, show polyembryony, where a single fertilized egg divides into
many and in some cases thousands of separate embryos.[34]:136–137 Insects may be univoltine,
bivoltine or multivoltine, i.e. they may have one, two or many broods (generations) in a
year.[79]

Other developmental and reproductive variations include

haplodiploidy, polymorphism, paedomorphosis or
A pair of grasshoppers mating. peramorphosis, sexual dimorphism, parthenogenesis and
more rarely hermaphroditism.[34]:143 In haplodiploidy,
which is a type of sex-determination system, the
offspring's sex is determined by the number of sets of chromosomes an individual receives.
This system is typical in bees and wasps.[80] Polymorphism is where a species may have
different morphs or forms, as in the oblong winged katydid, which has four different
varieties: green, pink and yellow or tan. Some insects may retain phenotypes that are
normally only seen in juveniles; this is called paedomorphosis. In peramorphosis, an
opposite sort of phenomenon, insects take on previously unseen traits after they have
matured into adults. Many insects display sexual dimorphism, in which males and females
have notably different appearances, such as the moth Orgyia recens as an exemplar of
sexual dimorphism in insects.

Some insects use parthenogenesis, a process in which the female can reproduce and give
The different forms of the male (top)
birth without having the eggs fertilized by a male. Many aphids undergo a form of
and female (bottom) tussock moth
parthenogenesis, called cyclical parthenogenesis, in which they alternate between one or Orgyia recens is an example of
many generations of asexual and sexual reproduction.[81][82] In summer, aphids are sexual dimorphism in insects.
generally female and parthenogenetic; in the autumn, males may be produced for sexual
reproduction. Other insects produced by parthenogenesis are bees, wasps and ants, in
which they spawn males. However, overall, most individuals are female, which are produced by fertilization. The males are
haploid and the females are diploid.[7] More rarely, some insects display hermaphroditism, in which a given individual has both
male and female reproductive organs.

Insect life-histories show adaptations to withstand cold and dry conditions. Some temperate region insects are capable of
activity during winter, while some others migrate to a warmer climate or go into a state of torpor.[83] Still other insects have
evolved mechanisms of diapause that allow eggs or pupae to survive these conditions.[84]

Metamorphosis
Metamorphosis in insects is the biological process of development all insects must undergo. There are two forms of
metamorphosis: incomplete metamorphosis and complete metamorphosis.

Incomplete metamorphosis

Hemimetabolous insects, those with incomplete metamorphosis, change gradually by undergoing a series of molts. An insect
molts when it outgrows its exoskeleton, which does not stretch and would otherwise restrict the insect's growth. The molting
process begins as the insect's epidermis secretes a new epicuticle inside the old one. After this new epicuticle is secreted, the
epidermis releases a mixture of enzymes that digests the endocuticle and thus detaches the old cuticle. When this stage is
complete, the insect makes its body swell by taking in a large quantity of water or air, which makes the old cuticle split along
predefined weaknesses where the old exocuticle was thinnest.[34]:142[85]
Immature insects that go through incomplete metamorphosis are called nymphs or in the case of dragonflies and damselflies,
also naiads. Nymphs are similar in form to the adult except for the presence of wings, which are not developed until adulthood.
With each molt, nymphs grow larger and become more similar in appearance to adult insects.

This southern hawker dragonfly molts its exoskeleton several times during its life as a nymph; shown is the final molt to become a winged adult (eclosion).

Complete metamorphosis

Holometabolism, or complete metamorphosis, is where the insect changes in four

stages, an egg or embryo, a larva, a pupa and the adult or imago. In these species, an
egg hatches to produce a larva, which is generally worm-like in form. This worm-like
form can be one of several varieties: eruciform (caterpillar-like), scarabaeiform (grub-
like), campodeiform (elongated, flattened and active), elateriform (wireworm-like) or
vermiform (maggot-like). The larva grows and eventually becomes a pupa, a stage
marked by reduced movement and often sealed within a cocoon. There are three types
of pupae: obtect, exarate or coarctate. Obtect pupae are compact, with the legs and
other appendages enclosed. Exarate pupae have their legs and other appendages free
and extended. Coarctate pupae develop inside the larval skin.[34]:151 Insects undergo
considerable change in form during the pupal stage, and emerge as adults. Butterflies
are a well-known example of insects that undergo complete metamorphosis, although
most insects use this life cycle. Some insects have evolved this system to
hypermetamorphosis.
Gulf fritillary life cycle, an example of
Complete metamorphosis is a trait of the most diverse insect group, the
holometabolism.
Endopterygota.[34]:143 Endopterygota includes 11 Orders, the largest being Diptera
(flies), Lepidoptera (butterflies and moths), and Hymenoptera (bees, wasps, and ants),
and Coleoptera (beetles). This form of development is exclusive to insects and not seen in any other arthropods.

Senses and communication

Many insects possess very sensitive and specialized organs of perception. Some insects such as bees can perceive ultraviolet
wavelengths, or detect polarized light, while the antennae of male moths can detect the pheromones of female moths over
distances of many kilometers.[86] The yellow paper wasp (Polistes versicolor) is known for its wagging movements as a form of
communication within the colony; it can waggle with a frequency of 10.6±2.1 Hz (n=190). These wagging movements can signal
the arrival of new material into the nest and aggression between workers can be used to stimulate others to increase foraging
expeditions.[87] There is a pronounced tendency for there to be a trade-off between visual acuity and chemical or tactile acuity,
such that most insects with well-developed eyes have reduced or simple antennae, and vice versa. There are a variety of
different mechanisms by which insects perceive sound; while the patterns are not universal, insects can generally hear sound if
they can produce it. Different insect species can have varying hearing, though most insects can hear only a narrow range of
frequencies related to the frequency of the sounds they can produce. Mosquitoes have been found to hear up to 2 kHz, and
some grasshoppers can hear up to 50 kHz.[88] Certain predatory and parasitic insects can detect the characteristic sounds made
by their prey or hosts, respectively. For instance, some nocturnal moths can perceive the ultrasonic emissions of bats, which
helps them avoid predation.[34]:87–94 Insects that feed on blood have special sensory structures that can detect infrared
emissions, and use them to home in on their hosts.

Some insects display a rudimentary sense of numbers,[89] such as the solitary wasps that prey upon a single species. The
mother wasp lays her eggs in individual cells and provides each egg with a number of live caterpillars on which the young feed
when hatched. Some species of wasp always provide five, others twelve, and others as high as twenty-four caterpillars per cell.
The number of caterpillars is different among species, but always the same for each sex of larva. The male solitary wasp in the
genus Eumenes is smaller than the female, so the mother of one species supplies him with only five caterpillars; the larger
female receives ten caterpillars in her cell.

Light production and vision

A few insects, such as members of the families Poduridae and Onychiuridae (Collembola), Mycetophilidae (Diptera) and the
beetle families Lampyridae, Phengodidae, Elateridae and Staphylinidae are bioluminescent. The most familiar group are the
fireflies, beetles of the family Lampyridae. Some species are able to control this light
generation to produce flashes. The function varies with some species using them to attract
mates, while others use them to lure prey. Cave dwelling larvae of Arachnocampa
(Mycetophilidae, fungus gnats) glow to lure small flying insects into sticky strands of
silk.[90] Some fireflies of the genus Photuris mimic the flashing of female Photinus species
to attract males of that species, which are then captured and devoured.[91] The colors of
emitted light vary from dull blue (Orfelia fultoni, Mycetophilidae) to the familiar greens
and the rare reds (Phrixothrix tiemanni, Phengodidae).[92]

Most insects, except some species of cave crickets, are able to perceive light and dark. Many
species have acute vision capable of detecting minute movements. The eyes may include
simple eyes or ocelli as well as compound eyes of varying sizes. Many species are able to
detect light in the infrared, ultraviolet and the visible light wavelengths. Color vision has
been demonstrated in many species and phylogenetic analysis suggests that UV-green-blue
trichromacy existed from at least the Devonian period between 416 and 359 million years
ago.[93]

Sound production and hearing Most insects have compound eyes

and two antennae.
Insects were the earliest organisms to produce and sense sounds. Insects make sounds
mostly by mechanical action of appendages. In grasshoppers and crickets, this is achieved
by stridulation. Cicadas make the loudest sounds among the insects by producing and amplifying sounds with special
modifications to their body to form tymbals and associated musculature. The African cicada Brevisana brevis has been
measured at 106.7 decibels at a distance of 50 cm (20 in).[94] Some insects, such as the Helicoverpa zea moths, hawk moths
and Hedylid butterflies, can hear ultrasound and take evasive action when they sense that they have been detected by
bats.[95][96] Some moths produce ultrasonic clicks that were once thought to have a role in jamming bat echolocation. The
ultrasonic clicks were subsequently found to be produced mostly by unpalatable moths to warn bats, just as warning
colorations are used against predators that hunt by sight.[97] Some otherwise palatable moths have evolved to mimic these
calls.[98] More recently, the claim that some moths can jam bat sonar has been revisited. Ultrasonic recording and high-speed
infrared videography of bat-moth interactions suggest the palatable tiger moth really does defend against attacking big brown
bats using ultrasonic clicks that jam bat sonar.[99]

Very low sounds are also produced in various species of Coleoptera, Hymenoptera, Lepidoptera, Mantodea and Neuroptera.
These low sounds are simply the sounds made by the insect's movement. Through microscopic stridulatory structures located
on the insect's muscles and joints, the normal sounds of the insect moving are amplified and can be used to warn or
communicate with other insects. Most sound-making insects also have tympanal organs that can perceive airborne sounds.
Some species in Hemiptera, such as the corixids (water boatmen), are known to communicate via underwater sounds.[100] Most
insects are also able to sense vibrations transmitted through surfaces.

Communication using surface-borne vibrational signals is more widespread among insects

0:00 MENU
because of size constraints in producing air-borne sounds.[101] Insects cannot effectively
produce low-frequency sounds, and high-frequency sounds tend to disperse more in a Cricket in garage with familiar call.
dense environment (such as foliage), so insects living in such environments communicate
primarily using substrate-borne vibrations.[102] The mechanisms of production of
vibrational signals are just as diverse as those for producing sound in insects.

Some species use vibrations for communicating within members of the same species, such as to attract mates as in the songs of
the shield bug Nezara viridula.[103] Vibrations can also be used to communicate between entirely different species; lycaenid
(gossamer-winged butterfly) caterpillars, which are myrmecophilous (living in a mutualistic association with ants)
communicate with ants in this way.[104] The Madagascar hissing cockroach has the ability to press air through its spiracles to
make a hissing noise as a sign of aggression;[105] the death's-head hawkmoth makes a squeaking noise by forcing air out of their
pharynx when agitated, which may also reduce aggressive worker honey bee behavior when the two are in close proximity.[106]

Chemical communication
Chemical communications in animals rely on a variety of aspects including taste and smell. Chemoreception is the physiological
response of a sense organ (i.e. taste or smell) to a chemical stimulus where the chemicals act as signals to regulate the state or
activity of a cell. A semiochemical is a message-carrying chemical that is meant to attract, repel, and convey information. Types
of semiochemicals include pheromones and kairomones. One example is the butterfly Phengaris arion which uses chemical
signals as a form of mimicry to aid in predation.[107]

In addition to the use of sound for communication, a wide range of insects have evolved chemical means for communication.
These chemicals, termed semiochemicals, are often derived from plant metabolites include those meant to attract, repel and
provide other kinds of information. Pheromones, a type of semiochemical, are used for attracting mates of the opposite sex, for
aggregating conspecific individuals of both sexes, for deterring other individuals from approaching, to mark a trail, and to
trigger aggression in nearby individuals. Allomones benefit their producer by the effect they have upon the receiver.
Kairomones benefit their receiver instead of their producer. Synomones benefit the producer and the receiver. While some
chemicals are targeted at individuals of the same species, others are used for communication across species. The use of scents is
especially well known to have developed in social insects.[34]:96–105

Social behavior
Social insects, such as termites, ants and many bees and wasps, are the most familiar
species of eusocial animals.[108] They live together in large well-organized colonies that
may be so tightly integrated and genetically similar that the colonies of some species are
sometimes considered superorganisms. It is sometimes argued that the various species of
honey bee are the only invertebrates (and indeed one of the few non-human groups) to
have evolved a system of abstract symbolic communication where a behavior is used to
represent and convey specific information about something in the environment. In this
communication system, called dance language, the angle at which a bee dances represents a
direction relative to the sun, and the length of the dance represents the distance to be
flown.[34]:309–311 Though perhaps not as advanced as honey bees, bumblebees also
potentially have some social communication behaviors. Bombus terrestris, for example,
exhibit a faster learning curve for visiting unfamiliar, yet rewarding flowers, when they can
see a conspecific foraging on the same species.[109]

Only insects that live in nests or colonies demonstrate any true capacity for fine-scale
spatial orientation or homing. This can allow an insect to return unerringly to a single hole
A cathedral mound created by
a few millimeters in diameter among thousands of apparently identical holes clustered termites (Isoptera).
together, after a trip of up to several kilometers' distance. In a phenomenon known as
philopatry, insects that hibernate have shown the ability to recall a specific location up to a
year after last viewing the area of interest.[110] A few insects seasonally migrate large distances between different geographic
regions (e.g., the overwintering areas of the monarch butterfly).[34]:14

Care of young
The eusocial insects build nests, guard eggs, and provide food for offspring full-time (see Eusociality). Most insects, however,
lead short lives as adults, and rarely interact with one another except to mate or compete for mates. A small number exhibit
some form of parental care, where they will at least guard their eggs, and sometimes continue guarding their offspring until
adulthood, and possibly even feeding them. Another simple form of parental care is to construct a nest (a burrow or an actual
construction, either of which may be simple or complex), store provisions in it, and lay an egg upon those provisions. The adult
does not contact the growing offspring, but it nonetheless does provide food. This sort of care is typical for most species of bees
and various types of wasps.[111]

Locomotion

Flight
Insects are the only group of invertebrates to have developed flight. The evolution of insect
wings has been a subject of debate. Some entomologists suggest that the wings are from
paranotal lobes, or extensions from the insect's exoskeleton called the nota, called the
paranotal theory. Other theories are based on a pleural origin. These theories include
suggestions that wings originated from modified gills, spiracular flaps or as from an
appendage of the epicoxa. The epicoxal theory suggests the insect wings are modified
epicoxal exites, a modified appendage at the base of the legs or coxa.[112] In the White-lined sphinx moth feeding in
Carboniferous age, some of the Meganeura dragonflies had as much as a 50 cm (20 in) flight
wide wingspan. The appearance of gigantic insects has been found to be consistent with
high atmospheric oxygen. The respiratory system of insects constrains their size, however
the high oxygen in the atmosphere allowed larger sizes.[113] The largest flying insects today are much smaller and include
several moth species such as the Atlas moth and the white witch (Thysania agrippina).

Insect flight has been a topic of great interest in aerodynamics due partly to the inability of steady-state theories to explain the
lift generated by the tiny wings of insects. But insect wings are in motion, with flapping and vibrations, resulting in churning
and eddies, and the misconception that physics says "bumblebees can't fly" persisted throughout most of the twentieth century.

Unlike birds, many small insects are swept along by the prevailing winds[114] although many of the larger insects are known to
make migrations. Aphids are known to be transported long distances by low-level jet streams.[115] As such, fine line patterns
associated with converging winds within weather radar imagery, like the WSR-88D radar network, often represent large groups
of insects.[116]
Walking
Many adult insects use six legs for walking and have adopted a tripedal gait. The
tripedal gait allows for rapid walking while always having a stable stance and has been
studied extensively in cockroaches and ants. The legs are used in alternate triangles
touching the ground. For the first step, the middle right leg and the front and rear left
legs are in contact with the ground and move the insect forward, while the front and
rear right leg and the middle left leg are lifted and moved forward to a new position.
When they touch the ground to form a new stable triangle the other legs can be lifted
and brought forward in turn and so on.[117] The purest form of the tripedal gait is seen
in insects moving at high speeds. However, this type of locomotion is not rigid and
insects can adapt a variety of gaits. For example, when moving slowly, turning, Basic motion of the insect wing in insect
avoiding obstacles, climbing or slippery surfaces, four (tetrapod) or more feet (wave- with an indirect flight mechanism scheme
gait[118]) may be touching the ground. Insects can also adapt their gait to cope with the of dorsoventral cut through a thorax
loss of one or more limbs. segment with
a wings
Cockroaches are among the fastest insect runners and, at full speed, adopt a bipedal b joints
run to reach a high velocity in proportion to their body size. As cockroaches move very c dorsoventral muscles
quickly, they need to be video recorded at several hundred frames per second to reveal d longitudinal muscles.
their gait. More sedate locomotion is seen in the stick insects or walking sticks
(Phasmatodea). A few insects have evolved to walk on the surface of the water,
especially members of the Gerridae family, commonly known as water striders. A few
species of ocean-skaters in the genus Halobates even live on the surface of open
oceans, a habitat that has few insect species.[119]

Use in robotics

Insect walking is of particular interest as an alternative form of locomotion in robots.

The study of insects and bipeds has a significant impact on possible robotic methods of
transport. This may allow new robots to be designed that can traverse terrain that
robots with wheels may be unable to handle.[117]
Spatial and temporal stepping pattern of
walking desert ants performing an
alternating tripod gait. Recording rate: 500
Swimming
fps, Playback rate: 10 fps.

A large number of insects live either part or the whole of their lives underwater. In
many of the more primitive orders of insect, the immature stages are spent in an
aquatic environment. Some groups of insects, like certain water beetles, have aquatic adults
as well.[72]

Many of these species have adaptations to help in under-water locomotion. Water beetles
and water bugs have legs adapted into paddle-like structures. Dragonfly naiads use jet
propulsion, forcibly expelling water out of their rectal chamber.[120] Some species like the
water striders are capable of walking on the surface of water. They can do this because their
claws are not at the tips of the legs as in most insects, but recessed in a special groove
further up the leg; this prevents the claws from piercing the water's surface film.[72] Other The backswimmer Notonecta glauca
insects such as the Rove beetle Stenus are known to emit pygidial gland secretions that underwater, showing its paddle-like
reduce surface tension making it possible for them to move on the surface of water by hindleg adaptation
Marangoni propulsion (also known by the German term
Entspannungsschwimmen).[121][122]

Ecology
Insect ecology is the scientific study of how insects, individually or as a community, interact with the surrounding environment
or ecosystem.[123]:3 Insects play one of the most important roles in their ecosystems, which includes many roles, such as soil
turning and aeration, dung burial, pest control, pollination and wildlife nutrition. An example is the beetles, which are
scavengers that feed on dead animals and fallen trees and thereby recycle biological materials into forms found useful by other
organisms.[124] These insects, and others, are responsible for much of the process by which topsoil is created.[34]:3, 218–228

Defense and predation

Insects are mostly soft bodied, fragile and almost defenseless compared to other, larger lifeforms. The immature stages are
small, move slowly or are immobile, and so all stages are exposed to predation and parasitism. Insects then have a variety of
defense strategies to avoid being attacked by predators or parasitoids. These include camouflage, mimicry, toxicity and active
defense.[126]
Camouflage is an important defense strategy, which involves the use of coloration or shape to blend into the surrounding
environment.[127] This sort of protective coloration is common and widespread among beetle families, especially those that feed
on wood or vegetation, such as many of the leaf beetles (family Chrysomelidae) or weevils. In some of these species, sculpturing
or various colored scales or hairs cause the beetle to resemble bird dung or other inedible objects. Many of those that live in
sandy environments blend in with the coloration of the substrate.[126] Most phasmids are known for effectively replicating the
forms of sticks and leaves, and the bodies of some species (such as O. macklotti and Palophus centaurus) are covered in mossy
or lichenous outgrowths that supplement their disguise. Very rarely, a species may
have the ability to change color as their surroundings shift (Bostra scabrinota). In a
further behavioral adaptation to supplement crypsis, a number of species have been
noted to perform a rocking motion where the body is swayed from side to side that is
thought to reflect the movement of leaves or twigs swaying in the breeze. Another
method by which stick insects avoid predation and resemble twigs is by feigning death
(catalepsy), where the insect enters a motionless state that can be maintained for a
long period. The nocturnal feeding habits of adults also aids Phasmatodea in remaining
concealed from predators.[128]

Another defense that often uses color or shape to deceive potential enemies is mimicry.
A number of longhorn beetles (family Cerambycidae) bear a striking resemblance to
wasps, which helps them avoid predation even though the beetles are in fact
harmless.[126] Batesian and Müllerian mimicry complexes are commonly found in
Lepidoptera. Genetic polymorphism and natural selection give rise to otherwise edible
species (the mimic) gaining a survival advantage by resembling inedible species (the
model). Such a mimicry complex is referred to as Batesian. One of the most famous
examples, where the viceroy butterfly was long believed to be a Batesian mimic of the
inedible monarch, was later disproven, as the viceroy is more toxic than the monarch,
Perhaps one of the most well-known
and this resemblance is now considered to be a case of Müllerian mimicry.[125] In examples of mimicry, the viceroy butterfly
Müllerian mimicry, inedible species, usually within a taxonomic order, find it (top) appears very similar to the monarch
advantageous to resemble each other so as to reduce the sampling rate by predators butterfly (bottom).[125]
who need to learn about the insects' inedibility. Taxa from the toxic genus Heliconius
form one of the most well known Müllerian complexes.[129]

Chemical defense is another important defense found among species of Coleoptera and Lepidoptera, usually being advertised
by bright colors, such as the monarch butterfly. They obtain their toxicity by sequestering the chemicals from the plants they
eat into their own tissues. Some Lepidoptera manufacture their own toxins. Predators that eat poisonous butterflies and moths
may become sick and vomit violently, learning not to eat those types of species; this is actually the basis of Müllerian mimicry.
A predator who has previously eaten a poisonous lepidopteran may avoid other species with similar markings in the future,
thus saving many other species as well.[130] Some ground beetles of the family Carabidae can spray chemicals from their
abdomen with great accuracy, to repel predators.[126]

Pollination
Pollination is the process by which pollen is transferred in the reproduction of plants,
thereby enabling fertilisation and sexual reproduction. Most flowering plants require an
animal to do the transportation. While other animals are included as pollinators, the
majority of pollination is done by insects.[131] Because insects usually receive benefit for the
pollination in the form of energy rich nectar it is a grand example of mutualism. The
various flower traits (and combinations thereof) that differentially attract one type of
pollinator or another are known as pollination syndromes. These arose through complex
plant-animal adaptations. Pollinators find flowers through bright colorations, including
European honey bee carrying pollen
ultraviolet, and attractant pheromones. The study of pollination by insects is known as
in a pollen basket back to the hive
anthecology.

Parasitism
Many insects are parasites of other insects such as the parasitoid wasps. These insects are known as entomophagous parasites.
They can be beneficial due to their devastation of pests that can destroy crops and other resources. Many insects have a
parasitic relationship with humans such as the mosquito. These insects are known to spread diseases such as malaria and
yellow fever and because of such, mosquitoes indirectly cause more deaths of humans than any other animal.

Relationship to humans

As pests
Many insects are considered pests by humans. Insects commonly regarded as pests include those that are parasitic (e.g. lice,
bed bugs), transmit diseases (mosquitoes, flies), damage structures (termites), or destroy agricultural goods (locusts, weevils).
Many entomologists are involved in various forms of pest control, as in research for companies to produce insecticides, but
increasingly rely on methods of biological pest control, or biocontrol. Biocontrol uses one
organism to reduce the population density of another organism—the pest—and is
considered a key element of integrated pest management.[132][133]

Despite the large amount of effort focused at controlling insects, human attempts to kill
pests with insecticides can backfire. If used carelessly, the poison can kill all kinds of
organisms in the area, including insects' natural predators, such as birds, mice and other
insectivores. The effects of DDT's use exemplifies how some insecticides can threaten
wildlife beyond intended populations of pest insects.[134][135]

Aedes aegypti, a parasite, is the

In beneficial roles vector of dengue fever and yellow
fever
Although pest insects attract the most attention, many
insects are beneficial to the environment and to
humans. Some insects, like wasps, bees, butterflies and ants, pollinate flowering plants.
Pollination is a mutualistic relationship between plants and insects. As insects gather
nectar from different plants of the same species, they also spread pollen from plants on
which they have previously fed. This greatly increases plants' ability to cross-pollinate,
which maintains and possibly even improves their evolutionary fitness. This ultimately
affects humans since ensuring healthy crops is critical to agriculture. As well as pollination
ants help with seed distribution of plants. This helps to spread the plants, which increases
Because they help flowering plants to plant diversity. This leads to an overall better environment.[136] A serious environmental
cross-pollinate, some insects are problem is the decline of populations of pollinator insects, and a number of species of
critical to agriculture. This European insects are now cultured primarily for pollination management in order to have sufficient
honey bee is gathering nectar while pollinators in the field, orchard or greenhouse at bloom time.[137]:240–243 Another solution,
pollen collects on its body.
as shown in Delaware, has been to raise native plants to help support native pollinators like
L. vierecki.[138] Insects also produce useful substances such as honey, wax, lacquer and
silk. Honey bees have been cultured by humans for thousands of years for honey, although
contracting for crop pollination is becoming more significant for beekeepers. The silkworm
has greatly affected human history, as silk-driven trade established relationships between
China and the rest of the world.

Insectivorous insects, or insects that feed on other insects, are beneficial to humans if they
eat insects that could cause damage to agriculture and human structures. For example,
aphids feed on crops and cause problems for farmers, but ladybugs feed on aphids, and can
be used as a means to significantly reduce pest aphid populations. While birds are perhaps
A robberfly with its prey, a hoverfly. more visible predators of insects, insects themselves account for the vast majority of insect
Insectivorous relationships such as consumption. Ants also help control animal populations by consuming small
these help control insect populations.
vertebrates.[139] Without predators to keep them in check, insects can undergo almost
unstoppable population explosions.[34]:328–348[34]:400[140][141]

Insects are also used in medicine, for example fly larvae (maggots) were formerly used to treat wounds to prevent or stop
gangrene, as they would only consume dead flesh. This treatment is finding modern usage in some hospitals. Recently insects
have also gained attention as potential sources of drugs and other medicinal substances.[142] Adult insects, such as crickets and
insect larvae of various kinds, are also commonly used as fishing bait.[143]

In research
Insects play important roles in biological research. For example, because of its small size,
short generation time and high fecundity, the common fruit fly Drosophila melanogaster is
a model organism for studies in the genetics of higher eukaryotes. D. melanogaster has
been an essential part of studies into principles like genetic linkage, interactions between
genes, chromosomal genetics, development, behavior and evolution. Because genetic
systems are well conserved among eukaryotes, understanding basic cellular processes like
DNA replication or transcription in fruit flies can help to understand those processes in
other eukaryotes, including humans.[144] The genome of D. melanogaster was sequenced
in 2000, reflecting the organism's important role in biological research. It was found that
70% of the fly genome is similar to the human genome, supporting the evolution The common fruitfly Drosophila
theory.[145] melanogaster is one of the most
widely used organisms in biological
research.
As food
In some cultures, insects, especially deep-fried cicadas, are considered to be delicacies, whereas in other places they form part
of the normal diet. Insects have a high protein content for their mass, and some authors suggest their potential as a major
source of protein in human nutrition.[34]:10–13 In most first-world countries, however, entomophagy (the eating of insects), is
taboo.[146] Since it is impossible to entirely eliminate pest insects from the human food chain, insects are inadvertently present
in many foods, especially grains. Food safety laws in many countries do not prohibit insect parts in food, but rather limit their
quantity. According to cultural materialist anthropologist Marvin Harris, the eating of insects is taboo in cultures that have
other protein sources such as fish or livestock.

Due to the abundance of insects and a worldwide concern of food shortages, the Food and Agriculture Organization of the
United Nations considers that the world may have to, in the future, regard the prospects of eating insects as a food staple.
Insects are noted for their nutrients, having a high content of protein, minerals and fats and are eaten by one-third of the global
population.[147]

As feed
Several insect species such as the black soldier fly or the housefly in their maggot forms, as well as beetle larvae such as
mealworms can be processed and used as feed for farmed animals such as chicken, fish and pigs.[148]

In other products
Insect larvae (i.e. black soldier fly larvae) can provide protein, grease, and chitin. The grease is usable in the pharmaceutical
industry (cosmetics,[149] surfactants for shower gel) -hereby replacing other vegetable oils as palm oil.[150]

Also, insect cooking oil, insect butter and fatty alcohols can be made from such insects as the superworm (Zophobas
morio).[151][152]

As pets
Many species of insects are sold and kept as pets.

In culture
Scarab beetles held religious and cultural symbolism in Old Egypt, Greece and some shamanistic Old World cultures. The
ancient Chinese regarded cicadas as symbols of rebirth or immortality. In Mesopotamian literature, the epic poem of
Gilgamesh has allusions to Odonata that signify the impossibility of immortality. Among the Aborigines of Australia of the
Arrernte language groups, honey ants and witchety grubs served as personal clan totems. In the case of the 'San' bush-men of
the Kalahari, it is the praying mantis that holds much cultural significance including creation and zen-like patience in
waiting.[34]:9

See also
Chemical ecology
Defense in insects
Entomology
Ethnoentomology
Flying and gliding animals
Insect biodiversity
Insect ecology
Insect-borne diseases
Prehistoric insects
Pain in invertebrates

References
1. Engel, Michael S.; David A. Grimaldi (2004). "New light shed on the oldest insect". Nature. 427 (6975): 627–630.
Bibcode:2004Natur.427..627E (https://ui.adsabs.harvard.edu/abs/2004Natur.427..627E). doi:10.1038/nature02291 (https://
doi.org/10.1038%2Fnature02291). PMID 14961119 (https://pubmed.ncbi.nlm.nih.gov/14961119).
2. Chapman, A.D. (2006). Numbers of living species in Australia and the World (http://www.deh.gov.au/biodiversity/abrs/public
ations/other/species-numbers/index.html). Canberra: Australian Biological Resources Study. ISBN 978-0-642-56850-2.
3. Wilson, E.O. "Threats to Global Diversity" (https://web.archive.org/web/20150220154543/http://www.globalchange.umich.ed
u/globalchange2/current/lectures/biodiversity/biodiversity.html). Archived from the original (http://www.globalchange.umich.e
du/globalchange2/current/lectures/biodiversity/biodiversity.html) on 20 February 2015. Retrieved 17 May 2009.
4. Novotny, Vojtech; Basset, Yves; Miller, Scott E.; Weiblen, George D.; Bremer, Birgitta; Cizek, Lukas; Drozd, Pavel (2002).
 "Low host specificity of herbivorous insects in a tropical forest". Nature. 416 (6883): 841–844.
Bibcode:2002Natur.416..841N (https://ui.adsabs.harvard.edu/abs/2002Natur.416..841N). doi:10.1038/416841a (https://doi.o
rg/10.1038%2F416841a). PMID 11976681 (https://pubmed.ncbi.nlm.nih.gov/11976681).
5. Erwin, Terry L. (1997). Biodiversity at its utmost: Tropical Forest Beetles (http://entomology.si.edu/StaffPages/Erwin/T's%20
updated%20pub%20PDFs%2010Jan2014/121_1995_Biodiversity-at-its-utmost.pdf) (PDF). pp. 27–40. Archived (https://we
b.archive.org/web/20181109151957/https://entomology.si.edu/staffpages/Erwin/T's%20updated%20pub%20PDFs%2010Ja
n2014/121_1995_Biodiversity-at-its-utmost.pdf) (PDF) from the original on 9 November 2018. Retrieved 16 December
2017. In: Reaka-Kudla, M.L.; Wilson, D.E.; Wilson, E.O. (eds.). Biodiversity II (https://archive.org/details/biodiversityiiun00re
ak). Joseph Henry Press, Washington, D.C.
6. Erwin, Terry L. (1982). "Tropical forests: their richness in Coleoptera and other arthropod species" (https://repository.si.edu/
bitstream/handle/10088/4383/Classic_papers_in_Foundations.pdf?sequence=1&isAllowed=y) (PDF). The Coleopterists
Bulletin. 36: 74–75. Archived (https://web.archive.org/web/20150923014947/https://repository.si.edu/bitstream/handle/1008
8/4383/Classic_papers_in_Foundations.pdf?sequence=1&isAllowed=y) (PDF) from the original on 23 September 2015.
Retrieved 16 September 2018.
7. "insect physiology" McGraw-Hill Encyclopedia of Science and Technology, Ch. 9, p. 233, 2007
8. Vincent Brian Wigglesworth. "Insect" (http://www.britannica.com/EBchecked/topic/289001/insect). Encyclopædia Britannica
online. Archived (https://web.archive.org/web/20120504183402/http://www.britannica.com/EBchecked/topic/289001/insect)
from the original on 4 May 2012. Retrieved 19 April 2012.
9. Damian Carrington. "Insects could be the key to meeting food needs of growing global population (https://www.theguardian.
com/environment/2010/aug/01/insects-food-emissions) Archived (https://web.archive.org/web/20180616203853/https://ww
w.theguardian.com/environment/2010/aug/01/insects-food-emissions) 16 June 2018 at the Wayback Machine", The
Guardian 1 August 2010. Retrieved 27 February 2011.
10. Ramos-Elorduy, Julieta; Menzel, Peter (1998). Creepy crawly cuisine: the gourmet guide to edible insects (https://books.go
ogle.com/?id=Q7f1LkFz11gC). Inner Traditions / Bear & Company. p. 44. ISBN 978-0-89281-747-4. Retrieved 23 April
2014.
11. Harper, Douglas; Dan McCormack (November 2001). "Online Etymological Dictionary" (http://www.etymonline.com/index.p
hp?term=insect&allowed_in_frame=0). LogoBee.com. p. 1. Archived (https://web.archive.org/web/20120111164850/http://w
ww.etymonline.com/index.php?term=insect&allowed_in_frame=0) from the original on 11 January 2012. Retrieved
1 November 2011.
12. "Insect translations" (http://www.ezglot.com/words.php?w=insect&l=eng).
13. Sasaki, Go; Sasaki, Keisuke; Machida, Ryuichiro; Miyata, Takashi & Su, Zhi-Hui (2013). "Molecular phylogenetic analyses
support the monophyly of Hexapoda and suggest the paraphyly of Entognatha" (https://www.ncbi.nlm.nih.gov/pmc/articles/
PMC4228403). BMC Evolutionary Biology. 13: 236. doi:10.1186/1471-2148-13-236 (https://doi.org/10.1186%2F1471-2148-
13-236). PMC 4228403 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4228403). PMID 24176097 (https://pubmed.ncbi.nl
m.nih.gov/24176097).
14. Chinery 1993, p. 10.
15. Chinery 1993, pp. 34–35.
16. Kjer, Karl M.; Simon, Chris; Yavorskaya, Margarita & Beutel, Rolf G. (2016). "Progress, pitfalls and parallel universes: a
history of insect phylogenetics" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5014063). Journal of the Royal Society
Interface. 13 (121): 121. doi:10.1098/rsif.2016.0363 (https://doi.org/10.1098%2Frsif.2016.0363). PMC 5014063 (https://ww
w.ncbi.nlm.nih.gov/pmc/articles/PMC5014063). PMID 27558853 (https://pubmed.ncbi.nlm.nih.gov/27558853).
17. Hughes, Joseph & Longhorn, Stuart (2016). "The role of next generation sequencing technologies in shaping the future of
insect molecular systematics" (https://books.google.com/books?hl=en&lr=&id=C3JNDAAAQBAJ&oi=fnd&pg=PA28). In
Olson, Peter D.; Hughes, Joseph & Cotton, James A. (eds.). Next Generation Systematics. Cambridge University Press.
pp. 28–61. ISBN 978-1-139-23635-5. Retrieved 27 July 2017., pp. 29–30
18. "Arthropoda" (http://www.tolweb.org/Arthropoda). Tree of Life. Tree of Life Web Project. 1995. Archived (https://web.archive.
org/web/20090506025632/http://tolweb.org/arthropoda) from the original on 6 May 2009. Retrieved 9 May 2009.
19. Russell Garwood; Gregory Edgecombe (2011). "Early terrestrial animals, evolution and uncertainty". Evolution: Education
and Outreach. 4 (3): 489–501. doi:10.1007/s12052-011-0357-y (https://doi.org/10.1007%2Fs12052-011-0357-y).
20. "Palaeos invertebrates:Arthropoda" (https://web.archive.org/web/20090215010139/http://palaeos.com/Invertebrates/Arthrop
ods/Pancrustacea.html). Palaeos Invertebrates. 3 May 2002. Archived from the original (http://www.palaeos.com/Invertebra
tes/Arthropods/Pancrustacea.html) on 15 February 2009. Retrieved 6 May 2009.
21. Misof, Bernhard; et al. (7 November 2014). "Phylogenomics resolves the timing and pattern of insect evolution" (http://www.
sciencemag.org). Science. 346 (6210): 763–767. Bibcode:2014Sci...346..763M (https://ui.adsabs.harvard.edu/abs/2014Sci.
..346..763M). doi:10.1126/science.1257570 (https://doi.org/10.1126%2Fscience.1257570). PMID 25378627 (https://pubmed
.ncbi.nlm.nih.gov/25378627). Archived (https://web.archive.org/web/20091018132952/http://www.sciencemag.org/) from the
original on 18 October 2009. Retrieved 17 October 2009.
22. "Evolution of insect flight" (http://dml.cmnh.org/1994Oct/msg00116.html). Malcolm W. Browne. 25 October 1994. Archived (
https://web.archive.org/web/20070218015237/http://dml.cmnh.org/1994Oct/msg00116.html) from the original on 18
February 2007. Retrieved 6 May 2009.
23. "Researchers Discover Oldest Fossil Impression of a Flying Insect" (http://newswise.com/articles/view/545296/). Newswise.
14 October 2008. Archived (https://web.archive.org/web/20141110032001/http://newswise.com/articles/view/545296/) from
the original on 10 November 2014. Retrieved 21 September 2014.
24. Rice, C.M.; Ashcroft, W.A.; Batten, D.J.; Boyce, A.J.; Caulfield, J.B.D.; Fallick, A.E.; Hole, M.J.; Jones, E.; Pearson, M.J.;
Rogers, G.; Saxton, J.M.; Stuart, F.M.; Trewin, N.H.; Turner, G. (1995). "A Devonian auriferous hot spring system, Rhynie,
Scotland". Journal of the Geological Society, London. 152 (2): 229–250. Bibcode:1995JGSoc.152..229R (https://ui.adsabs.
harvard.edu/abs/1995JGSoc.152..229R). doi:10.1144/gsjgs.152.2.0229 (https://doi.org/10.1144%2Fgsjgs.152.2.0229).
25. Wiegmann BM, Trautwein MD, Winkler IS, Barr NB, Kim JW, Lambkin C, Bertone MA, Cassel BK, Bayless KM, Heimberg
AM, Wheeler BM, Peterson KJ, Pape T, Sinclair BJ, Skevington JH, Blagoderov V, Caravas J, Kutty SN, Schmidt-Ott U,
 Kampmeier GE, Thompson FC, Grimaldi DA, Beckenbach AT, Courtney GW, Friedrich M, Meier R, Yeates DK (2011).
"Episodic radiations in the fly tree of life" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3078341). Proceedings of the
National Academy of Sciences. 108 (14): 5690–5695. Bibcode:2011PNAS..108.5690W (https://ui.adsabs.harvard.edu/abs/2
011PNAS..108.5690W). doi:10.1073/pnas.1012675108 (https://doi.org/10.1073%2Fpnas.1012675108). PMC 3078341 (http
s://www.ncbi.nlm.nih.gov/pmc/articles/PMC3078341). PMID 21402926 (https://pubmed.ncbi.nlm.nih.gov/21402926).
26. Grimaldi, D.; Engel, M. S. (2005). Evolution of the Insects. Cambridge University Press. ISBN 978-0-521-82149-0.
27. Garwood, Russell J.; Sutton, Mark D. (2010). "X-ray micro-tomography of Carboniferous stem-Dictyoptera: New insights
into early insects" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2936155). Biology Letters. 6 (5): 699–702.
doi:10.1098/rsbl.2010.0199 (https://doi.org/10.1098%2Frsbl.2010.0199). PMC 2936155 (https://www.ncbi.nlm.nih.gov/pmc/
articles/PMC2936155). PMID 20392720 (https://pubmed.ncbi.nlm.nih.gov/20392720).
28. Rasnitsyn, A.P.; Quicke, D.L.J. (2002). History of Insects. Kluwer Academic Publishers. ISBN 978-1-4020-0026-3.
29. J. Stein Carter (29 March 2005). "Coevolution and Pollination" (https://web.archive.org/web/20090430183230/http://biology.
clc.uc.edu/Courses/bio303/coevolution.htm). University of Cincinnati. Archived from the original (http://biology.clc.uc.edu/co
urses/bio303/coevolution.htm) on 30 April 2009. Retrieved 9 May 2009.
30. Sroka, Günter; Staniczek, Arnold H.; Bechly (December 2014). "Revision of the giant pterygote insect Bojophlebia prokopi
Kukalová-Peck 1985 (Hydropalaeoptera: Bojophlebiidae) from the Carboniferous of the Czech Republic, with the first
cladistic analysis of fossil palaeopterous insects" (https://www.researchgate.net/publication/269920314). Journal of
Systematic Palaeontology. 13 (11): 963–982. doi:10.1080/14772019.2014.987958 (https://doi.org/10.1080%2F14772019.2
014.987958). Retrieved 21 May 2019.
31. Prokop, Jakub (2017). "Redefining the extinct orders Miomoptera & Hypoperlida as stem acercarian insects" (https://hal.sor
bonne-universite.fr/hal-01589476/document). BMC Evolutionary Biology. 17: 205. doi:10.1186/s12862-017-1039-3 (https://d
oi.org/10.1186%2Fs12862-017-1039-3). PMC 5574135 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5574135).
PMID 28841819 (https://pubmed.ncbi.nlm.nih.gov/28841819). Retrieved 21 May 2017.
32. Wipfler, B (February 2019). "Evolutionary history of Polyneoptera & its implications for our understanding of early winged
insects". Proceedings of the National Academy of Sciences. 116 (8): 3024–3029. doi:10.1073/pnas.1817794116 (https://doi
.org/10.1073%2Fpnas.1817794116).
33. "Insecta" (http://www.tolweb.org/Insecta/8205). Tree of Life Web Project. 2002. Archived (https://web.archive.org/web/2009
0414174042/http://tolweb.org/Insecta/8205) from the original on 14 April 2009. Retrieved 12 May 2009.
34. Gullan, P.J.; Cranston, P.S. (2005). The Insects: An Outline of Entomology (https://archive.org/details/isbn_9781405111133)
(3rd ed.). Oxford: Blackwell Publishing. ISBN 978-1-4051-1113-3.
35. Kendall, David A. (2009). "Classification of Insect" (https://web.archive.org/web/20090520201746/http://www.kendall-biores
earch.co.uk/class.htm). Archived from the original (http://www.kendall-bioresearch.co.uk/class.htm) on 20 May 2009.
Retrieved 9 May 2009.
36. Gilliott, Cedric (1995). Entomology (https://books.google.com/?id=DrTKxvZq_IcC&pg=PA96) (2nd ed.). Springer-Verlag
New York, LLC. p. 96. ISBN 978-0-306-44967-3.
37. Kapoor, V.C.C. (1998). Principles and Practices of Animal Taxonomy. 1 (1st ed.). Science Publishers. p. 48. ISBN 978-1-
57808-024-3.
38. Johnson, K. P.; Yoshizawa, K.; Smith, V. S. (2004). "Multiple origins of parasitism in lice" (https://www.ncbi.nlm.nih.gov/pmc/
articles/PMC1691793). Proceedings of the Royal Society of London. 271 (1550): 1771–1776. doi:10.1098/rspb.2004.2798 (
https://doi.org/10.1098%2Frspb.2004.2798). PMC 1691793 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1691793).
PMID 15315891 (https://pubmed.ncbi.nlm.nih.gov/15315891).
39. Terry, M. D.; Whiting, M. F. (2005). "Mantophasmatodea and phylogeny of the lower neopterous insects" (https://www.resea
rchgate.net/publication/227604832). Cladistics. 21 (3): 240–257. doi:10.1111/j.1096-0031.2005.00062.x (https://doi.org/10.1
111%2Fj.1096-0031.2005.00062.x).
40. Lo, Nathan; Tokuda, Gaku; Watanabe, Hirofumi; Rose, Harley; Slaytor, Michael; Maekawa, Kiyoto; Bandi, Claudio; Noda,
Hiroaki (2000). "Evidence from multiple gene sequences indicates that termites evolved from wood-feeding cockroaches".
Current Biology. 10 (13): 801–804. doi:10.1016/S0960-9822(00)00561-3 (https://doi.org/10.1016%2FS0960-9822%2800%2
900561-3). PMID 10898984 (https://pubmed.ncbi.nlm.nih.gov/10898984).
41. Bonneton, F.; Brunet, F.G.; Kathirithamby J. & Laudet, V. (2006). "The rapid divergence of the ecdysone receptor is a
synapomorphy for Mecopterida that clarifies the Strepsiptera problem". Insect Molecular Biology. 15 (3): 351–362.
doi:10.1111/j.1365-2583.2006.00654.x (https://doi.org/10.1111%2Fj.1365-2583.2006.00654.x). PMID 16756554 (https://pub
med.ncbi.nlm.nih.gov/16756554).
42. Whiting, M.F. (2002). "Mecoptera is paraphyletic: multiple genes and phylogeny of Mecoptera and Siphonaptera" (https://se
manticscholar.org/paper/d3537d8be461ca0419bc02920d0f4d69b50c0214). Zoologica Scripta. 31 (1): 93–104.
doi:10.1046/j.0300-3256.2001.00095.x (https://doi.org/10.1046%2Fj.0300-3256.2001.00095.x).
43. Sahney, S.; Benton, M.J.; Falcon-Lang, H.J. (2010). "Rainforest collapse triggered Pennsylvanian tetrapod diversification in
Euramerica" (https://semanticscholar.org/paper/c5d4c814a4bef9c0556a7210282a65470f9f682e). Geology. 38 (12): 1079–
1082. Bibcode:2010Geo....38.1079S (https://ui.adsabs.harvard.edu/abs/2010Geo....38.1079S). doi:10.1130/G31182.1 (http
s://doi.org/10.1130%2FG31182.1).
44. "Coevolution and Pollination" (https://web.archive.org/web/20090430183230/http://biology.clc.uc.edu/Courses/bio303/coevo
lution.htm). University of Cincinnati. Archived from the original (http://biology.clc.uc.edu/courses/bio303/coevolution.htm) on
30 April 2009. Retrieved 9 May 2009.
45. Stork, Nigel E. (7 January 2018). "How Many Species of Insects and Other Terrestrial Arthropods Are There on Earth?" (htt
ps://semanticscholar.org/paper/77cd50721ab3e98487cd43c0b4d1d1ad8bd72b07). Annual Review of Entomology. 63 (1):
31–45. doi:10.1146/annurev-ento-020117-043348 (https://doi.org/10.1146%2Fannurev-ento-020117-043348).
PMID 28938083 (https://pubmed.ncbi.nlm.nih.gov/28938083).
46. Dirzo, Rodolfo; Young, Hillary; Galetti, Mauro; Ceballos, Gerardo; Isaac, Nick; Collen, Ben (25 July 2014), "Defaunation in
the Anthropocene" (http://discovery.ucl.ac.uk/1436030/1/Collen_Dirzo%20etal%202014%20Science%20Accepted.pdf)
(PDF), Science, 345 (6195): 401–406, doi:10.1126/science.1251817 (https://doi.org/10.1126%2Fscience.1251817),
 PMID 25061202 (https://pubmed.ncbi.nlm.nih.gov/25061202), archived (https://web.archive.org/web/20170922095643/http:
//discovery.ucl.ac.uk/1436030/1/Collen_Dirzo%20etal%202014%20Science%20Accepted.pdf) (PDF) from the original on
22 September 2017, retrieved 28 April 2019
47. Briggs, John C (October 2017). "Emergence of a sixth mass extinction?". Biological Journal of the Linnean Society. 122 (2):
243–248. doi:10.1093/biolinnean/blx063 (https://doi.org/10.1093%2Fbiolinnean%2Fblx063).
48. Owens, Avalon C. S.; Lewis, Sara M. (November 2018). "The impact of artificial light at night on nocturnal insects: A review
and synthesis" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6262936). Ecology and Evolution. 8 (22): 11337–11358.
doi:10.1002/ece3.4557 (https://doi.org/10.1002%2Fece3.4557). PMC 6262936 (https://www.ncbi.nlm.nih.gov/pmc/articles/P
MC6262936). PMID 30519447 (https://pubmed.ncbi.nlm.nih.gov/30519447).
49. Tscharntke, Teja; Klein, Alexandra M.; Kruess, Andreas; Steffan-Dewenter, Ingolf; Thies, Carsten (August 2005).
"Landscape perspectives on agricultural intensification and biodiversity and ecosystem service management" (https://sema
nticscholar.org/paper/137128a6623ab5265983db14636a0df94b954735). Ecology Letters. 8 (8): 857–874.
doi:10.1111/j.1461-0248.2005.00782.x (https://doi.org/10.1111%2Fj.1461-0248.2005.00782.x).
50. Insect-plant interactions in a crop protection perspective. 19 January 2017. pp. 313–320. ISBN 978-0-12-803324-1.
51. Braak, Nora; Neve, Rebecca; Jones, Andrew K.; Gibbs, Melanie; Breuker, Casper J. (November 2018). "The effects of
insecticides on butterflies – A review" (https://radar.brookes.ac.uk/radar/items/fddc88d3-25f2-4274-9321-2f9b3b72047a/1).
Environmental Pollution. 242 (Pt A): 507–518. doi:10.1016/j.envpol.2018.06.100 (https://doi.org/10.1016%2Fj.envpol.2018.
06.100). PMID 30005263 (https://pubmed.ncbi.nlm.nih.gov/30005263).
52. Wagner, David L.; Van Driesche, Roy G. (January 2010). "Threats Posed to Rare or Endangered Insects by Invasions of
Nonnative Species". Annual Review of Entomology. 55 (1): 547–568. doi:10.1146/annurev-ento-112408-085516 (https://doi.
org/10.1146%2Fannurev-ento-112408-085516). PMID 19743915 (https://pubmed.ncbi.nlm.nih.gov/19743915).
53. Sánchez-Bayo, Francisco; Wyckhuys, Kris A.G. (April 2019). "Worldwide decline of the entomofauna: A review of its
drivers". Biological Conservation. 232: 8–27. doi:10.1016/j.biocon.2019.01.020 (https://doi.org/10.1016%2Fj.biocon.2019.0
1.020).
54. Saunders, Manu (16 February 2019). "Insectageddon is a great story. But what are the facts?" (https://ecologyisnotadirtywo
rd.com/2019/02/16/insectageddon-is-a-great-story-but-what-are-the-facts/). Ecology is not a dirty word. Archived (https://we
b.archive.org/web/20190225044750/https://ecologyisnotadirtyword.com/2019/02/16/insectageddon-is-a-great-story-but-wha
t-are-the-facts/) from the original on 25 February 2019. Retrieved 24 February 2019.
55. van Klink, Roel (24 April 2020), "Meta-analysis reveals declines in terrestrial but increases in freshwater insect
abundances" (https://science.sciencemag.org/content/368/6489/417), Science, doi:10.1126/science.aax9931 (https://doi.or
g/10.1126%2Fscience.aax9931)
56. McGrath, Matt (23 April 2020). " 'Insect apocalypse' more complex than thought" (https://www.bbc.com/news/science-enviro
nment-52399373). BBC News. Retrieved 24 April 2020.
57. "Global Insect Biodiversity: Frequently Asked Questions" (http://www.entsoc.org/sites/default/files/files/Science-Policy/2019/
Global%20Insect%20Biodiversity%20FAQs.pdf) (PDF). Entomological Society of America. Retrieved 6 March 2019.
58. "O. Orkin Insect zoo" (https://web.archive.org/web/20090602045832/http://www.insectzoo.msstate.edu/Students/basic.struc
ture.html). The University of Nebraska Department of Entomology. Archived from the original (http://insectzoo.msstate.edu/
Students/basic.structure.html) on 2 June 2009. Retrieved 3 May 2009.
59. Resh, Vincent H.; Ring T. Carde (2009). Encyclopedia of Insects (2 ed.). U.S: Academic Press. ISBN 978-0-12-374144-8.
60. Schneiderman, Howard A. (1960). "Discontinuous respiration in insects: role of the spiracles" (http://www.biolbull.org/cgi/rep
rint/119/3/494?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=insect+thoracic+spiracle&andorexactfulltext=a
nd&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT). The Biological Bulletin. 119 (3): 494–528.
doi:10.2307/1539265 (https://doi.org/10.2307%2F1539265). JSTOR 1539265 (https://www.jstor.org/stable/1539265).
Archived (https://web.archive.org/web/20090625011339/http://www.biolbull.org/cgi/reprint/119/3/494?maxtoshow=&HITS=1
0&hits=10&RESULTFORMAT=&fulltext=insect+thoracic+spiracle&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&so
rtspec=relevance&resourcetype=HWCIT) from the original on 25 June 2009. Retrieved 22 May 2009.
61. Eisemann, C.H.; Jorgensen, W.K.; Merritt, D.J.; Rice, M.J.; Cribb, B.W.; Webb, P.D.; Zalucki, M.P. (1984). "Do insects feel
pain? – A biological view". Cellular and Molecular Life Sciences. 40 (2): 1420–1423. doi:10.1007/BF01963580 (https://doi.or
g/10.1007%2FBF01963580).
62. Tracey, J; Wilson, RI; Laurent, G; Benzer, S (2003). "painless, a Drosophila gene essential for nociception". Cell. 113 (2):
261–273. doi:10.1016/S0092-8674(03)00272-1 (https://doi.org/10.1016%2FS0092-8674%2803%2900272-1).
PMID 12705873 (https://pubmed.ncbi.nlm.nih.gov/12705873).
63. Sømme, LS (14 January 2005). "Sentience and pain in invertebrates" (http://www.vkm.no/dav/413af9502e.pdf) (PDF).
Norwegian Scientific Committee for Food Safety. Archived (https://web.archive.org/web/20111017040616/http://www.vkm.n
o/dav/413af9502e.pdf) (PDF) from the original on 17 October 2011. Retrieved 30 September 2009.
64. "Evolutionary Biology of Insect Learning" (http://www.annualreviews.org/eprint/5PHddkgYYKaduPp4CcN5/full/10.1146/annu
rev.ento.53.103106.093343), Annual Review of Entomology, Vol. 53: 145–160
65. "General Entomology – Digestive and Excritory system" (http://www.cals.ncsu.edu/course/ent425/library/tutorials/internal_a
natomy/digestive.html). NC state University. Archived (https://web.archive.org/web/20090523024349/http://www.cals.ncsu.e
du/course/ent425/library/tutorials/internal_anatomy/digestive.html) from the original on 23 May 2009. Retrieved 3 May
2009.
66. Bueno, Odair Correa; Tanaka, Francisco André Ossamu; de Lima Nogueira, Neusa; Fox, Eduardo Gonçalves Paterson;
Rossi, Mônica Lanzoni; Solis, Daniel Russ (1 January 2013). "On the morphology of the digestive system of two
Monomorium ant species" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3835044). Journal of Insect Science. 13 (1): 70.
doi:10.1673/031.013.7001 (https://doi.org/10.1673%2F031.013.7001). PMC 3835044 (https://www.ncbi.nlm.nih.gov/pmc/art
icles/PMC3835044). PMID 24224520 (https://pubmed.ncbi.nlm.nih.gov/24224520).
67. "General Entomology – Digestive and Excretory system" (http://www.cals.ncsu.edu/course/ent425/library/tutorials/internal_a
natomy/digestive.html). NC state University. Archived (https://web.archive.org/web/20090523024349/http://www.cals.ncsu.e
du/course/ent425/library/tutorials/internal_anatomy/digestive.html) from the original on 23 May 2009. Retrieved 3 May
 du/course/ent425/library/tutorials/internal_anatomy/digestive.html) from the original on 23 May 2009. Retrieved 3 May
2009.
68. Duncan, Carl D. (1939). A Contribution to The Biology of North American Vespine Wasps (1st ed.). Stanford: Stanford
University Press. pp. 24–29.
69. Nation, James L. (2001). "Digestion" (https://books.google.com/?id=l3v2tOvz1uQC&pg=PA31). Insect Physiology and
Biochemistry (1st ed.). CRC Press. ISBN 978-0-8493-1181-9.
70. "What Keeps Bugs from Being Bigger?" (https://web.archive.org/web/20170514060330/https://www1.aps.anl.gov/APS-Scie
nce-Highlight/2007/What-Keeps-Bugs-from-Being-Bigger). Argonne National Laboratory. 8 August 2007. Archived from the
original (https://www1.aps.anl.gov/APS-Science-Highlight/2007/What-Keeps-Bugs-from-Being-Bigger) on 14 May 2017.
Retrieved 15 July 2013.
71. Chown, S.L.; S.W. Nicholson (2004). Insect Physiological Ecology. New York: Oxford University Press. ISBN 978-0-19-
851549-4.
72. Richard W. Merritt; Kenneth W. Cummins; Martin B. Berg (editors) (2007). An Introduction to the Aquatic Insects of North
America (4th ed.). Kendall Hunt Publishers. ISBN 978-0-7575-5049-2.
73. Merritt, RW; KW Cummins & MB Berg (2007). An Introduction To The Aquatic Insects Of North America. Kendall Hunt
Publishing Company. ISBN 978-0-7575-4128-5.
74. Meyer, John R. (17 February 2006). "Circulatory System" (https://web.archive.org/web/20090927000720/http://www.cals.nc
su.edu/course/ent425/tutorial/circulatory.html). NC State University: Department of Entomology, NC State University. p. 1.
Archived from the original (http://www.cals.ncsu.edu/course/ent425/tutorial/circulatory.html) on 27 September 2009.
Retrieved 11 October 2009.
75. Triplehorn, Charles (2005). Borror and DeLong's introduction to the study of insects. Johnson, Norman F., Borror, Donald J.
(7th ed.). Belmont, CA: Thompson Brooks/Cole. pp. 27–28. ISBN 978-0030968358. OCLC 55793895 (https://www.worldcat
.org/oclc/55793895).
76. Chapman, R. F. (1998). The Insects; Structure and Function (https://archive.org/details/insectsstructure0000chap) (4th ed.).
Cambridge, UK: Cambridge University Press. ISBN 978-0521578905.
77. Wyatt, G.R. (1961). "The Biochemistry of Insect Hemolymph" (https://semanticscholar.org/paper/f5218cb8d670def949b184
b0a6ceeca464adb440). Annual Review of Entomology. 6: 75–102. doi:10.1146/annurev.en.06.010161.000451 (https://doi.o
rg/10.1146%2Fannurev.en.06.010161.000451).
78. Jacobs, C.G.; Rezende, G.L.; Lamers, G.E.; van der Zee, M. (2013). "The extraembryonic serosa protects the insect egg
against desiccation" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3712428). Proceedings of the Royal Society of London
B. 280 (1764): 20131082. doi:10.1098/rspb.2013.1082 (https://doi.org/10.1098%2Frspb.2013.1082). PMC 3712428 (https://
www.ncbi.nlm.nih.gov/pmc/articles/PMC3712428). PMID 23782888 (https://pubmed.ncbi.nlm.nih.gov/23782888).
79. "Glossary of Lepidopteran and Odonate anatomy" (http://www.vararespecies.org/glossary.shtml). Rare species atlas.
Virginia Department of Conservation and Recreation. 2013. Archived (https://web.archive.org/web/20131004213832/http://
www.vararespecies.org/glossary.shtml) from the original on 4 October 2013. Retrieved 14 June 2013.
80. Hughes, William O. H.; Oldroyd, Benjamin P.; Beekman, Madeleine; Ratnieks, Francis L. W. (2008). "Ancestral Monogamy
Shows Kin Selection Is Key to the Evolution of Eusociality". Science. 320 (5880): 1213–1216.
Bibcode:2008Sci...320.1213H (https://ui.adsabs.harvard.edu/abs/2008Sci...320.1213H). doi:10.1126/science.1156108 (http
s://doi.org/10.1126%2Fscience.1156108). PMID 18511689 (https://pubmed.ncbi.nlm.nih.gov/18511689).
81. Nevo, E.; Coll, M. (2001). "Effect of nitrogen fertilization on Aphis gossypii (Homoptera: Aphididae): variation in size, color,
and reproduction". Journal of Economic Entomology. 94 (1): 27–32. doi:10.1603/0022-0493-94.1.27 (https://doi.org/10.1603
%2F0022-0493-94.1.27). PMID 11233124 (https://pubmed.ncbi.nlm.nih.gov/11233124).
82. Jahn, G.C.; Almazan, L.P.; Pacia, J. (2005). "Effect of nitrogen fertilizer on the intrinsic rate of increase of the rusty plum
aphid, Hysteroneura setariae (Thomas) (Homoptera: Aphididae) on rice (Oryza sativa L.)" (http://webarchive.nationalarchiv
es.gov.uk/20100909141631/http%3A//docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/0046225x/v34n4s26.pdf)
(PDF). Environmental Entomology. 34 (4): 938–943. doi:10.1603/0046-225X-34.4.938 (https://doi.org/10.1603%2F0046-22
5X-34.4.938). Archived from the original (http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/0046225x/v34n4s2
6.pdf) (PDF) on 9 September 2010.
83. Debbie Hadley. "Where do insects go in winter?" (http://insects.about.com/od/adaptations/p/wintersurvival.htm). About.com.
Archived (https://web.archive.org/web/20120118125346/http://insects.about.com/od/adaptations/p/wintersurvival.htm) from
the original on 18 January 2012. Retrieved 19 April 2012.
84. Lee, Richard E Jr. (1989). "Insect Cold-Hardiness: To Freeze or Not to Freeze" (http://www.units.muohio.edu/cryolab/public
ations/documents/Lee89_BioSci.pdf) (PDF). BioScience. 39 (5): 308–313. doi:10.2307/1311113 (https://doi.org/10.2307%2
F1311113). JSTOR 1311113 (https://www.jstor.org/stable/1311113). Archived (https://web.archive.org/web/20110110023731/
http://www.units.muohio.edu/cryolab/publications/documents/Lee89_BioSci.pdf) (PDF) from the original on 10 January
2011. Retrieved 2 December 2009.
85. Ruppert, E.E.; Fox, R.S. & Barnes, R.D. (2004). Invertebrate Zoology (https://archive.org/details/isbn_9780030259821/pag
e/523) (7th ed.). Brooks / Cole. pp. 523–524 (https://archive.org/details/isbn_9780030259821/page/523). ISBN 978-0-03-
025982-1.
86. "Insects" (http://crazydaz.com/insects.pdf) (PDF). Alien Life Forms. p. 4. Archived (https://web.archive.org/web/2011070820
1217/http://crazydaz.com/insects.pdf) (PDF) from the original on 8 July 2011. Retrieved 17 May 2009.
87. Esch, Harald (1971). "Wagging Movements in the Wasp Polistes versicolor Vulgaris Bequaert". Zeitschrift für Vergleichende
Physiologie. 72 (3): 221–225. doi:10.1007/bf00297781 (https://doi.org/10.1007%2Fbf00297781).
88. Cator, L.J.; Arthur, B.J.; Harrington, L.C.; Hoy, R.R. (2009). "Harmonic convergence in the love songs of the dengue vector
mosquito" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2847473). Science. 323 (5917): 1077–1079.
Bibcode:2009Sci...323.1077C (https://ui.adsabs.harvard.edu/abs/2009Sci...323.1077C). doi:10.1126/science.1166541 (http
s://doi.org/10.1126%2Fscience.1166541). PMC 2847473 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2847473).
PMID 19131593 (https://pubmed.ncbi.nlm.nih.gov/19131593).
89. Möller, R. (2002). A Biorobotics Approach to the Study of Insect Visual Homing Strategies (http://www.ti.uni-bielefeld.de/do
 wnloads/publications/habil.pdf) (PDF) (in German). p. 11. Archived (https://web.archive.org/web/20110110023731/http://ww
w.ti.uni-bielefeld.de/downloads/publications/habil.pdf) (PDF) from the original on 10 January 2011. Retrieved 23 April 2009.
90. Pugsley, Chris W. (1983). "Literature review of the New Zealand glowworm Arachnocampa luminosa (Diptera: Keroplatidae)
and related cave-dwelling Diptera" (https://web.archive.org/web/20071020094802/http://www.ento.org.nz/nzentomologist/fr
ee_issues/NZEnto07_4_1983/Volume%207-4-419-424.pdf) (PDF). New Zealand Entomologist. 7 (4): 419–424.
doi:10.1080/00779962.1983.9722435 (https://doi.org/10.1080%2F00779962.1983.9722435). Archived from the original (htt
p://www.ento.org.nz/nzentomologist/free_issues/NZEnto07_4_1983/Volume%207-4-419-424.pdf) (PDF) on 20 October
2007.
91. Lloyd, James E. (1984). "Occurrence of Aggressive Mimicry in Fireflies" (https://semanticscholar.org/paper/f11aa2641d31c1
e1e5578821c6edb060a943ebc8). The Florida Entomologist. 67 (3): 368–376. doi:10.2307/3494715 (https://doi.org/10.2307
%2F3494715). JSTOR 3494715 (https://www.jstor.org/stable/3494715).
92. Lloyd, James E.; Erin C. Gentry (2003). The Encyclopedia of Insects (https://archive.org/details/encyclopediaofin00bada/pa
ge/115). Academic Press. pp. 115–120 (https://archive.org/details/encyclopediaofin00bada/page/115). ISBN 978-0-12-
586990-4.
93. Briscoe, AD; Chittka, L (2001). "The evolution of color vision in insects" (https://semanticscholar.org/paper/195de55dbf4fa7
44998682d1542a386f34430ac8). Annual Review of Entomology. 46: 471–510. doi:10.1146/annurev.ento.46.1.471 (https://d
oi.org/10.1146%2Fannurev.ento.46.1.471). PMID 11112177 (https://pubmed.ncbi.nlm.nih.gov/11112177).
94. Walker, T.J., ed. (2001). University of Florida Book of Insect Records (http://entnemdept.ifas.ufl.edu/walker/ufbir/index.shtml
) Archived (https://web.archive.org/web/20121208115924/http://entnemdept.ifas.ufl.edu/walker/ufbir/index.shtml) 8
December 2012 at the Wayback Machine.
95. Kay, Robert E. (1969). "Acoustic signalling and its possible relationship to assembling and navigation in the moth, Heliothis
zea". Journal of Insect Physiology. 15 (6): 989–1001. doi:10.1016/0022-1910(69)90139-5 (https://doi.org/10.1016%2F0022-
1910%2869%2990139-5).
96. Spangler, Hayward G. (1988). "Moth hearing, defense, and communication". Annual Review of Entomology. 33 (1): 59–81.
doi:10.1146/annurev.ento.33.1.59 (https://doi.org/10.1146%2Fannurev.ento.33.1.59).
97. Hristov, N.I.; Conner, W.E. (2005). "Sound strategy: acoustic aposematism in the bat–tiger moth arms race".
Naturwissenschaften. 92 (4): 164–169. Bibcode:2005NW.....92..164H (https://ui.adsabs.harvard.edu/abs/2005NW.....92..16
4H). doi:10.1007/s00114-005-0611-7 (https://doi.org/10.1007%2Fs00114-005-0611-7). PMID 15772807 (https://pubmed.nc
bi.nlm.nih.gov/15772807).
98. Barber, J.R.; W.E. Conner (2007). "Acoustic mimicry in a predator–prey interaction" (https://www.ncbi.nlm.nih.gov/pmc/articl
es/PMC1890494). Proceedings of the National Academy of Sciences. 104 (22): 9331–9334.
Bibcode:2007PNAS..104.9331B (https://ui.adsabs.harvard.edu/abs/2007PNAS..104.9331B).
doi:10.1073/pnas.0703627104 (https://doi.org/10.1073%2Fpnas.0703627104). PMC 1890494 (https://www.ncbi.nlm.nih.gov
/pmc/articles/PMC1890494). PMID 17517637 (https://pubmed.ncbi.nlm.nih.gov/17517637).
99. Corcoran, Aaron J.; Jesse R. Barber; William E. Conner (2009). "Tiger Moth Jams Bat Sonar" (https://semanticscholar.org/p
aper/e3ab897bd7b8a27ee336a9685c783b0b96bbd310). Science. 325 (5938): 325–327. Bibcode:2009Sci...325..325C (http
s://ui.adsabs.harvard.edu/abs/2009Sci...325..325C). doi:10.1126/science.1174096 (https://doi.org/10.1126%2Fscience.1174
096). PMID 19608920 (https://pubmed.ncbi.nlm.nih.gov/19608920).
00. Theiss, Joachim (1982). "Generation and radiation of sound by stridulating water insects as exemplified by the corixids".
Behavioral Ecology and Sociobiology. 10 (3): 225–235. doi:10.1007/BF00299689
(https://doi.org/10.1007%2FBF00299689).
01. Virant-Doberlet, M.; Čokl A. (2004). "Vibrational communication in insects". Neotropical Entomology. 33 (2): 121–134.
doi:10.1590/S1519-566X2004000200001 (https://doi.org/10.1590%2FS1519-566X2004000200001).
02. Bennet-Clark, H.C. (1998). "Size and scale effects as constraints in insect sound communication" (https://www.ncbi.nlm.nih.
gov/pmc/articles/PMC1692226). Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences.
353 (1367): 407–419. doi:10.1098/rstb.1998.0219 (https://doi.org/10.1098%2Frstb.1998.0219). PMC 1692226 (https://www.
ncbi.nlm.nih.gov/pmc/articles/PMC1692226).
03. Miklas, Nadège; Stritih, Nataša; Čokl, Andrej; Virant-Doberlet, Meta; Renou, Michel (2001). "The Influence of Substrate on
Male Responsiveness to the Female Calling Song in Nezara viridula". Journal of Insect Behavior. 14 (3): 313–332.
doi:10.1023/A:1011115111592 (https://doi.org/10.1023%2FA%3A1011115111592).
04. DeVries, P.J. (1990). "Enhancement of symbiosis between butterfly caterpillars and ants by vibrational communication".
Science. 248 (4959): 1104–1106. Bibcode:1990Sci...248.1104D (https://ui.adsabs.harvard.edu/abs/1990Sci...248.1104D).
doi:10.1126/science.248.4959.1104 (https://doi.org/10.1126%2Fscience.248.4959.1104). PMID 17733373 (https://pubmed.
ncbi.nlm.nih.gov/17733373).
05. Nelson, Margaret C.; Jean Fraser (1980). "Sound production in the cockroach, Gromphadorhina portentosa: evidence for
communication by hissing". Behavioral Ecology and Sociobiology. 6 (4): 305–314. doi:10.1007/BF00292773 (https://doi.org/
10.1007%2FBF00292773).
06. Moritz, R.F.A.; Kirchner, W.H.; Crewe, R.M. (1991). "Chemical camouflage of the death's head hawkmoth (Acherontia
atropos L.) in honeybee colonies". Naturwissenschaften. 78 (4): 179–182. Bibcode:1991NW.....78..179M (https://ui.adsabs.
harvard.edu/abs/1991NW.....78..179M). doi:10.1007/BF01136209 (https://doi.org/10.1007%2FBF01136209).
07. Thomas, Jeremy; Schönrogge, Karsten; Bonelli, Simona; Barbero, Francesca; Balletto, Emilio (2010). "Corruption of ant
acoustical signals by mimetic social parasites" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2889977). Communicative
and Integrative Biology. 3 (2): 169–171. doi:10.4161/cib.3.2.10603 (https://doi.org/10.4161%2Fcib.3.2.10603).
PMC 2889977 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2889977). PMID 20585513 (https://pubmed.ncbi.nlm.nih.gov
/20585513).
08. Brewer, Gary. "Social insects" (https://web.archive.org/web/20080321171246/http://www.ndsu.nodak.edu/entomology/topics
/societies.htm). North Dakota State University. Archived from the original (http://www.ndsu.nodak.edu/entomology/topics/so
cieties.htm) on 21 March 2008. Retrieved 6 May 2009.
09. Leadbeater, E.; L. Chittka (2007). "The dynamics of social learning in an insect model, the bumblebee (Bombus terrestris)".
 Behavioral Ecology and Sociobiology. 61 (11): 1789–1796. doi:10.1007/s00265-007-0412-4 (https://doi.org/10.1007%2Fs0
0265-007-0412-4).
10. Salt, R.W. (1961). "Principles of Insect Cold-Hardiness". Annual Review of Entomology. 6: 55–74.
doi:10.1146/annurev.en.06.010161.000415 (https://doi.org/10.1146%2Fannurev.en.06.010161.000415).
11. "Social Insects" (https://web.archive.org/web/20080321171246/http://www.ndsu.nodak.edu/entomology/topics/societies.htm
). North Dakota State University. Archived from the original (http://www.ndsu.nodak.edu/entomology/topics/societies.htm)
on 21 March 2008. Retrieved 12 October 2009.
12. Jockusch, EL; Ober, KA (September 2004). "Hypothesis testing in evolutionary developmental biology: a case study from
insect wings". Journal of Heredity. 95 (5): 382–396. doi:10.1093/jhered/esh064 (https://doi.org/10.1093%2Fjhered%2Fesh0
64). PMID 15388766 (https://pubmed.ncbi.nlm.nih.gov/15388766).
13. Dudley, R (1998). "Atmospheric oxygen, giant Paleozoic insects and the evolution of aerial locomotor performance" (http://j
eb.biologists.org/content/201/8/1043.full.pdf) (PDF). Journal of Experimental Biology. 201 (8): 1043–1050. Archived (https://
web.archive.org/web/20130124032600/http://jeb.biologists.org/content/201/8/1043.full.pdf) (PDF) from the original on 24
January 2013. Retrieved 8 December 2012.
14. Yates, Diana (2008). Birds migrate together at night in dispersed flocks, new study indicates. (http://news.illinois.edu/news/
08/0707birds.html) Archived (https://www.webcitation.org/68bxugwwF?url=http://news.illinois.edu/news/08/0707birds.html)
22 June 2012 at WebCite University of Illinois at Urbana–Champaign. Retrieved on 26 April 2009.
15. Drake, V.A.; R.A. Farrow (1988). "The Influence of Atmospheric Structure and Motions on Insect Migration". Annual Review
of Entomology. 33: 183–210. doi:10.1146/annurev.en.33.010188.001151 (https://doi.org/10.1146%2Fannurev.en.33.010188
.001151).
16. Bart Geerts and Dave Leon (2003). P5A.6 "Fine-Scale Vertical Structure of a Cold Front As Revealed By Airborne 95 GHZ
Radar" (http://www-das.uwyo.edu/wcr/projects/ihop02/coldfront_preprint.pdf) Archived (https://web.archive.org/web/200810
07173000/http://www-das.uwyo.edu/wcr/projects/ihop02/coldfront_preprint.pdf) 7 October 2008 at the Wayback Machine.
University of Wyoming. Retrieved on 26 April 2009.
17. Biewener, Andrew A (2003). Animal Locomotion. Oxford University Press. ISBN 978-0-19-850022-3.
18. Grabowska, Martyna; Godlewska, Elzbieta; Schmidt, Joachim; Daun-Gruhn, Silvia (2012). "Quadrupedal gaits in hexapod
animals – inter-leg coordination in free-walking adult stick insects". Journal of Experimental Biology. 215 (24): 4255–4266.
doi:10.1242/jeb.073643 (https://doi.org/10.1242%2Fjeb.073643). PMID 22972892 (https://pubmed.ncbi.nlm.nih.gov/229728
92).
19. Ikawa, Terumi; Okabe, Hidehiko; Hoshizaki, Sugihiko; Kamikado, Takahiro; Cheng, Lanna (2004). "Distribution of the
oceanic insects Halobates (Hemiptera: Gerridae) off the south coast of Japan". Entomological Science. 7 (4): 351–357.
doi:10.1111/j.1479-8298.2004.00083.x (https://doi.org/10.1111%2Fj.1479-8298.2004.00083.x).
20. Mill, P.J.; R.S. Pickard (1975). "Jet-propulsion in anisopteran dragonfly larvae". Journal of Comparative Physiology A. 97
(4): 329–338. doi:10.1007/BF00631969 (https://doi.org/10.1007%2FBF00631969).
21. Linsenmair, K.; Jander R. (1976). "Das "entspannungsschwimmen" von Velia and Stenus" (https://nbn-resolving.org/urn:nb
n:de:bvb:20-opus-44663). Naturwissenschaften. 50 (6): 231. Bibcode:1963NW.....50..231L (https://ui.adsabs.harvard.edu/a
bs/1963NW.....50..231L). doi:10.1007/BF00639292 (https://doi.org/10.1007%2FBF00639292).
22. Bush, J.W.M.; David L. Hu (2006). "Walking on Water: Biolocomotion at the Interface" (https://web.archive.org/web/200707
10022624/http://www.cims.nyu.edu/~dhu/Pubweb/Bush_Hu_06.pdf) (PDF). Annual Review of Fluid Mechanics. 38 (1):
339–369. Bibcode:2006AnRFM..38..339B (https://ui.adsabs.harvard.edu/abs/2006AnRFM..38..339B).
doi:10.1146/annurev.fluid.38.050304.092157 (https://doi.org/10.1146%2Fannurev.fluid.38.050304.092157). Archived from
the original (http://www.cims.nyu.edu/~dhu/Pubweb/Bush_Hu_06.pdf) (PDF) on 10 July 2007.
23. Schowalter, Timothy Duane (2006). Insect ecology: an ecosystem approach (https://books.google.com/books?id=3PD6R-A
EvwEC) (2nd (illustrated) ed.). Academic Press. p. 572. ISBN 978-0-12-088772-9. Archived (https://web.archive.org/web/20
160603221311/https://books.google.com/books?id=3PD6R-AEvwEC) from the original on 3 June 2016. Retrieved
27 October 2015.
24. Losey, John E.; Vaughan, Mace (2006). "The Economic Value of Ecological Services Provided by Insects" (http://wordinfo.in
fo/unit/3562?letter=I&spage=3). BioScience. 56 (4): 311–323(13). doi:10.1641/0006-3568(2006)56[311:TEVOES]2.0.CO;2 (
https://doi.org/10.1641%2F0006-3568%282006%2956%5B311%3ATEVOES%5D2.0.CO%3B2). Archived (https://web.archi
ve.org/web/20120112041609/http://wordinfo.info/unit/3562?letter=I&spage=3) from the original on 12 January 2012.
Retrieved 8 November 2011.
25. Ritland, D.B.; L.P. Brower (1991). "The viceroy butterfly is not a Batesian mimic". Nature. 350 (6318): 497–498.
Bibcode:1991Natur.350..497R (https://ui.adsabs.harvard.edu/abs/1991Natur.350..497R). doi:10.1038/350497a0 (https://doi.
org/10.1038%2F350497a0). "Viceroys are as unpalatable as monarchs, and significantly more unpalatable than queens
from representative Florida populations."
26. Evans, Arthur V.; Charles Bellamy (2000). An Inordinate Fondness for Beetles (https://books.google.com/?id=ZZ_hfpMo8o
AC&pg=PA31). University of California Press. ISBN 978-0-520-22323-3.
27. "Photos: Masters of Disguise – Amazing Insect Camouflage" (http://news.nationalgeographic.com/news/2014/03/140321-in
sects-fossil-camouflage-mimicry-pictures/). 24 March 2014. Archived (https://web.archive.org/web/20150612201555/http://n
ews.nationalgeographic.com/news/2014/03/140321-insects-fossil-camouflage-mimicry-pictures/) from the original on 12
June 2015. Retrieved 11 June 2015.
28. Bedford, Geoffrey O. (1978). "Biology and Ecology of the Phasmatodea". Annual Review of Entomology. 23: 125–149.
doi:10.1146/annurev.en.23.010178.001013 (https://doi.org/10.1146%2Fannurev.en.23.010178.001013).
29. Meyer, A. (2006). "Repeating Patterns of Mimicry" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1617347). PLoS Biology.
4 (10): e341. doi:10.1371/journal.pbio.0040341 (https://doi.org/10.1371%2Fjournal.pbio.0040341). PMC 1617347 (https://w
ww.ncbi.nlm.nih.gov/pmc/articles/PMC1617347). PMID 17048984 (https://pubmed.ncbi.nlm.nih.gov/17048984).
30. Kricher, John (1999). "6" (https://books.google.com/?id=Z3pgdvrSmG8C&pg=PA158). A Neotropical Companion. Princeton
University Press. pp. 157–158. ISBN 978-0-691-00974-2.
31. "Pollinator Factsheet" (https://web.archive.org/web/20080410135644/http://www.fs.fed.us/wildflowers/pollinators/documents
/factsheet_pollinator.pdf) (PDF). United States Forest Service. Archived from the original (http://www.fs.fed.us/wildflowers/p
ollinators/documents/factsheet_pollinator.pdf) (PDF) on 10 April 2008. Retrieved 19 April 2012.
32. Bale, JS; van Lenteren, JC; Bigler, F. (27 February 2008). "Biological control and sustainable food production" (https://www.
ncbi.nlm.nih.gov/pmc/articles/PMC2610108). Philosophical Transactions of the Royal Society of London. Series B,
Biological Sciences. 363 (1492): 761–776. doi:10.1098/rstb.2007.2182 (https://doi.org/10.1098%2Frstb.2007.2182).
PMC 2610108 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2610108). PMID 17827110 (https://pubmed.ncbi.nlm.nih.gov
/17827110).
33. Davidson, E. (2006). Big Fleas Have Little Fleas: How Discoveries of Invertebrate Diseases Are Advancing Modern
Science (https://archive.org/details/bigfleashavelitt0000davi). Tucson, Ariz.: University of Arizona Press. ISBN 978-0-8165-
2544-7.
34. Colborn, T; vom Saal, FS; Soto, AM (October 1993). "Developmental effects of endocrine-disrupting chemicals in wildlife
and humans" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1519860). Environmental Health Perspectives. 101 (5): 378–
384. doi:10.2307/3431890 (https://doi.org/10.2307%2F3431890). JSTOR 3431890 (https://www.jstor.org/stable/3431890).
PMC 1519860 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1519860). PMID 8080506 (https://pubmed.ncbi.nlm.nih.gov/
8080506).
35. Nakamaru, M; Iwasab, Y; Nakanishic, J (October 2003). "Extinction risk to bird populations caused by DDT exposure".
Chemosphere. 53 (4): 377–387. Bibcode:2003Chmsp..53..377N (https://ui.adsabs.harvard.edu/abs/2003Chmsp..53..377N).
doi:10.1016/S0045-6535(03)00010-9 (https://doi.org/10.1016%2FS0045-6535%2803%2900010-9). PMID 12946395 (https:
//pubmed.ncbi.nlm.nih.gov/12946395).
36. Holldobler, Wilson (1994). Journey to the ants: a story of scientific exploration (https://archive.org/details/journeytoantss00h
oll/page/196). Westminster college McGill Library: Cambridge, Mass.:Belknap Press of Haravard University Press, 1994.
pp. 196–199 (https://archive.org/details/journeytoantss00holl/page/196). ISBN 978-0-674-48525-9.
37. Smith, Deborah T (1991). Agriculture and the Environment: The 1991 Yearbook of Agriculture (https://books.google.com/?id
=fDTbAAAAMAAJ) (1991 ed.). United States Government Printing. ISBN 978-0-16-034144-1.
38. Kuehn, F. Coordinator. (2015). "Farming for native bees" (http://mysare.sare.org/sare_project/LNE07-261/?page=final)
Archived (https://web.archive.org/web/20160816152139/http://mysare.sare.org/sare_project/LNE07-261/?page=final) 16
August 2016 at the Wayback Machine. World Wide Web electronic publication. (Retrieved: September 22, 2015).
39. Camargo, Rafael; Paulo Oliveira (2011). "Natural history of the Neotrobical arboreal ant, Odontomachus hastatus: Nest
sites, foraging schedule, and diet" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3476954). Journal of Insect Science. 12
(18): 48. doi:10.1673/031.012.4801 (https://doi.org/10.1673%2F031.012.4801). PMC 3476954 (https://www.ncbi.nlm.nih.go
v/pmc/articles/PMC3476954). PMID 22957686 (https://pubmed.ncbi.nlm.nih.gov/22957686).
40. "Biocontrol Network – Beneficial Insects" (http://www.biconet.com/biocontrol.html). Biocontrol Network. Archived (https://we
b.archive.org/web/20090228043847/http://www.biconet.com/biocontrol.html) from the original on 28 February 2009.
Retrieved 9 May 2009.
41. Davidson, RH; William F. Lyon (1979). Insect Pests of Farm, Garden, and Orchard. Wiley, John & Sons. p. 38. ISBN 978-0-
471-86314-4.
42. Dossey, Aaron T. (December 2010). "Insects and their chemical weaponry: New potential for drug discovery". Natural
Product Reports. 27 (12): 1737–1757. doi:10.1039/c005319h (https://doi.org/10.1039%2Fc005319h). PMID 20957283 (http
s://pubmed.ncbi.nlm.nih.gov/20957283).
43. Sherman, Ronald A.; Pechter, Edward A. (1987). "Maggot therapy: a review of the therapeutic applications of fly larvae in
human medicine, especially for treating osteomyelitis". Medical and Veterinary Entomology. 2 (3): 225–230.
doi:10.1111/j.1365-2915.1988.tb00188.x (https://doi.org/10.1111%2Fj.1365-2915.1988.tb00188.x). PMID 2980178 (https://p
ubmed.ncbi.nlm.nih.gov/2980178).
44. Pierce, BA (2006). Genetics: A Conceptual Approach (https://archive.org/details/geneticsconceptu0000unse/page/87) (2nd
ed.). New York: W.H. Freeman and Company. p. 87 (https://archive.org/details/geneticsconceptu0000unse/page/87).
ISBN 978-0-7167-8881-2.
45. Adams, MD; Celniker, SE; Holt, RA; Evans, CA; Gocayne, JD; Amanatides, PG; Scherer, SE; Li, PW; et al. (24 March
2000). "The genome sequence of Drosophila melanogaster". Science. 287 (5461): 2185–2195.
Bibcode:2000Sci...287.2185. (https://ui.adsabs.harvard.edu/abs/2000Sci...287.2185.). CiteSeerX 10.1.1.549.8639 (https://ci
teseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.549.8639). doi:10.1126/science.287.5461.2185 (https://doi.org/10.1126%
2Fscience.287.5461.2185). PMID 10731132 (https://pubmed.ncbi.nlm.nih.gov/10731132).
46. Michels, John (1880). John Michels (ed.). Science (https://books.google.com/?id=aDkLAAAAYAAJ&pg=PA69). 1. American
Association for the Advance of Science. 229 Broadway ave., N.Y.: American Association for the Advance of Science.
pp. 2090pp. ISBN 978-1-930775-36-7.
47. Maierbrugger, Arno (14 May 2013). "UN: Insects are 'food of the future' (video)" (http://investvine.com/un-bugs-are-food-of-t
he-future-video/). Inside Investor. Archived (https://web.archive.org/web/20130910061538/http://investvine.com/un-bugs-ar
e-food-of-the-future-video/) from the original on 10 September 2013. Retrieved 17 May 2013.
48. AgriProtein using food and abattoir waste to farm maggots (https://www.wired.co.uk/article/food-of-larvae)
49. Insects as an alternative source for the production of fats for cosmetics (https://www.researchgate.net/publication/32667173
6_Insects_as_an_Alternative_Source_for_the_Production_of_Fats_for_Cosmetics)
50. EOS magazine, February 2020
51. Biteback Insect website (http://www.bitebackinsect.com/)
52. From Pest to Pot: Can Insects Feed the World? (https://www.nationalgeographic.com/culture/food/the-plate/2016/08/spons
or-content-from-pest-pot-can-insects-feed-the-world/)

Bibliography
 Chinery, Michael (1993), Insects of Britain & Northern Europe (3rd ed.), London, etc.: HarperCollins, ISBN 978-0-00-
219918-6

Further reading
Vogel, Gretchen (2017). "Where have all the insects gone?" (http://www.sciencemag.org/news/2017/05/where-have-all-inse
cts-gone). Science. doi:10.1126/science.aal1160 (https://doi.org/10.1126%2Fscience.aal1160).

External links
Insects of North America (http://bugguide.net/node/view/52/tree/)
Overview of Orders of Insects (http://bugguide.net/node/view/222292)
"Insect" (https://www.eol.org/pages/344) at the Encyclopedia of Life
A Safrinet Manual for Entomology and Arachnology (https://web.archive.org/web/20091122074740/http://www.spc.int/PPS/
SAFRINET/inse-scr.pdf) SPC
Tree of Life Project (http://tolweb.org/Insecta/8205) – Insecta, Insecta Movies (http://tolweb.org/movies/Insecta/8205)
Insect Morphology (https://web.archive.org/web/20110303060627/http://www.entomology.umn.edu/cues/4015/morpology/)
Overview of insect external and internal anatomy
Fossil Insect Database (http://edna.palass-hosting.org/) International Palaeoentological Society
UF Book of Insect Records (http://entomology.ifas.ufl.edu/walker/ufbir/)
InsectImages.org (http://www.insectimages.org/) 24,000 high resolution insect photographs
BBC Nature: (http://www.bbc.com/earth/tags/insect) Insect news, and video clips from BBC programmes past and present.
The Nature Explorers (http://www.thenatureexplorers.com/) Many insect video clips.

Retrieved from "https://en.wikipedia.org/w/index.php?title=Insect&oldid=953242127"

This page was last edited on 26 April 2020, at 11:38 (UTC).

Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use
and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.