3.

1Culicidae (Mosquito )
The word Culicidae is drived from the Latin word “culec” which means”gnat”
or “midge” ( how to resemblance with mosquitoes it's fun to be different
from mosquitoes some of it's auspicious are harmless or do not cause any
bite at all while some are painful when exposed to their biting). Culicidae has
been used to describe this kind of soft insect for century and still is used as
an interchangeable name for mosquito families. Culicidae spices found to be
numerous as it's includes about 3,600 species which are found world of
widely with the exception of Antarctica and some isolated Islands.

What are the key characteristics of Culicidae ?

Anatomy;- slender ( skinny) police with long legs and wings and the females are
found to a proboscis ( an elongated appendage on the head of animal functioning
for feeding, sensing and sucking.

Life cycle:- complete metamorphosis ( egg – larvae – pupa – adult )

Egg Stage: Female mosquitoes lay their eggs on the surface of stagnant water,
such as ponds, puddles, or even in containers like buckets and flowerpots and the
number of eggs laid depends on the spices while the hatching takes few days to
several weeks depending on the species and small in size less than 15mm in length

2. Larval Stage: Mosquito larvae, often called “wigglers,” live underwater and feed
on algae and organic matter in the water. They use siphons to breath in the water
surface and molt ( shade ) several times as they grow.

3. Pupal Stage :- their appearance in this stage is comma-shaped and do not feed
and slow a transitional period in which the larvae transforms to adult and in this
stage they breath through tubes called “ trumpets”

4. Adult Stage: Adult mosquitoes emerge from the pupal shell. While male mosquito
are fed on nectar female mosquito need blood meal to produce egg. diverse
habitats including freshwater bodies, swamps and urban areas
There are some behaviours that makes Culicidae that makes them to be
unique from others . Behaviours including;

Blood-feeding :- given to female mosquito , these species bite to obtain

blood for egg production .

Disease vectors:- many spices are vectors for serious diseases like malaria,
dengue and the likes

Diverse habitats:- they inhibit a wide range of habitat as mentioned above

( e.g. swamps, urban areas )

Nocturnal activity:- many spices of this insects are found to be active during
dusk and dawn

The above listed behaviours are what makes Culicidae to be different from
other organisms that are insects that may or may not harm our environment
or humans.

Culicidae or mosquito are of significant medical importance due to their role

playing as vectors for numerous diseases. They act as a transportation of
wide range of pathogens like viruses, bacteria and parasites. Disease caused
by mosquitos includes ;
Dengue fever :- a viral infections that causes fever, headache, muscle and
joint pain , skin rash and its transmitted by Aedes mosquito particularly
Aedes aegypti & Aedes albopictus

Zica virus :- a viral infection that can cause mild symptoms in most people
and is transmitted by Aedes mosquitos which lead to several health defect in
pregnant women.

Malaria:- thjs disease is a familiar one to all but to make some points
regarding it , it’s caused by the plasmodium parasite malaria which is a life
threatening to everyone but mostly habituated tropical and subtropical
regions that’s transmitted by Anopheles mosquito .

Yellow fever:- transmitted by Aedes mosquito , this diseases have a viral

haemorrhagic fever ( symptoms including fever ,bleeding , even organ
damage ) they can cause in the worst case scenario dearh.

Mosquito are of significant veterinary importance due to their role as vectors

for numerous diseases affecting animals these includes;

Eastern equine encephalitis ( EEE) :- affecting horses by causing severe

neurological disease and In an Extreme case death .

Western equine encephalitis ( WEE) :- mild to severe neurological disease on

horses

Heart worm disease:- concentrating on cats and dogs, mosquito transmit the
heart worm parasite, Dirofilaria limmitis and can cause severe heart and lung
damage

Equine infectious Anenia :- indirectly transmitted by mosquito by acting as

an immediate transfer between the virus and the horses

Reduced livestock productivity – by causing biting irritation and stress in

livestock, reducing weight gain , milk production, mosquito plays a
significant role in the agricultural ( particularly the live stocks) sector

We can reduce the effect of mosquito borne disease on animals by using;

Insect repellent:- using appropriate insect repellent on animals can help

reduce mosquito bite

Veterinary treatment:- prompt veterinary care help, manage and treat

mosquito airborne diseases.
Vaccinating :- vaccinating everyone including humans and animals, it can
widely help to reduce the severity of mosquito deiseas.

By understanding the vertenaty importance as well as medical

importance, we can greatly reduce the prevalence of mosquito engaging
disease and our immunity as well as our environment can begin a healthy
way.

3.2 psychodidae ( sand

fly)
Psychodidae ( phylum and class – inscta , order – diptera ) are well-known
for their diversity and also includes some sub-families with the most notable
thing phlebotominae ( commonly known as sand flies ). they are commonly
known as moth files, drain flies, or sewer gants that possessed hairy wing
bodies and wings that give them a moth- like appearance.

Additionally it’s important to note that not all psychodidaes are not sand files
even if all sand files are included in the family of psychodidae. Even if sand
flies are found in the sub- families of psychodidae (I.e. Phlebotominae), there
are some key differences that are found between the two families. These
includes;

Feeding habits :- while psychodidae are known for their not biting humans
behaviours, subfamily phlebotominae ( specifically the female sand fly ) are
blood-feeding insects that consequence are some diseases.

Disease transmission:- while the families of psychodidae are not considered

to be diseases vectors, subfamily phlebotominae ( specifically sand flies) are
found to be vectors for various diseases.

Medical importance:- psychodidae can be nuisance but are not to the

extreme degrees like that of phlebotomists ( we’ll try to cover this on a
deeper levels)

Habitat:- while psychodidae are commonly found in damp , organic-rich

environment , phlebotominaes are typically found in warm or arid to semi-
arid regions

Psychodidae (particularly sand flies) possess the following characteristics

that make them both similar and unique to other insects that are included in
this phylum’s sub- family characteristics including;

 Size:- small ranging from 0.3175 – 0.635 cm long

  Appearance:- like the others families and sub-families, they are
hairy and moth-like wings and grey to dark brown.
 Behaviours :- Nocturnal ( like that of mosquito active at night )
and also biting humans and animals at night causing them
considerable problems in their life and day to day activities.
 Habitat:- Thrive in warm and prefer humid environments and
sometimes are found in sandy and arid region.

When we come to the life cycle of sand flies, their life cycle is found to be a
complete metamorphosis one (i.e. Egg-adult-pupa-adult ). Let’s see them
one by one

Egg :- laid by female sand fly in a moist, organic matter ( soil , leaf litter ...),
its found to be small and oval shaped one . it’s incubation period depending
upon the environmental conditions takes about 4-20 days.

Larvae :- After the hatchment from the egg , they appear to be worm-like
They feed on organic matter in the soil, such as decaying plant material and
fungi. Larvae go through four instars before pupating. This stage can last
from 20 to 30 days, depending on environmental conditions.

Pupa: Larvae transform into pupae, which are immobile and encased in a
protective shell. This stage is fond to be a very important one as the insect
undergoes significant physical changes transforming into an adult. This stage
typically lasts 6-13 days.

Adult: adult sand flies emerge from the pupal cases. And the female sand
flies are the only ones that bite and feed on blood, which is necessary for
egg production. While males feed on plant nectar and other sugary
substances.

Even though Sand flies, belonging to the family Psychodidae, are small, hairy
insects , they can be significant vectors of various diseases affecting both
humans and animals. Let’s try to see them one by one;

Leishmaniasis: Sand flies are the primary vectors of Leishmania parasites,

which cause various forms of leishmaniasis.Leishmaniasis is a disease
caused by parasites of the genus Leishmania, which are transmitted by the
bite of infected female sand flies. These diseases can manifest as skin
lesions, organ damage, and even death however, It is a neglected tropical
disease that affects millions of people worldwide, primarily in tropical and
subtropical regions the forms of leishmaniasis can be in cutaneous (
common form that can take months and years to heal and can leave scars
and it can cause skin soars ) mucocutaneous ( a form that affects the
mucus membrane of the nose mouth and the throat that causes severe
tissue damage) visceral ( the most serious one that can cause that affects
the internal organs like the bone marrow, liver that can be fatal if left
untreated).

The major symptoms of this disease includes; spleen bleeding, skin soars,
fever , weight loss , anaemia. Diagnosis of leishmaniasis is typically made
through a combination of clinical examination, microscopic examination of
tissue samples, and laboratory tests. Antiseptic , surgery and
immunotherapy are some of the treatment methods of the disease. This
disease also is found in some dogs causing canine leishmaniasis, which can
be a serious and often fatal disease.

Phleboviruses: Some sand fly species transmit phleboviruses, which can

cause diseases like sandfly fever and Toscana virus infection.

Other Diseases: Sand flies may also vector other diseases affecting livestock
and other animals, although research in this area is ongoing.

Generally, the controlling of these diseases that are caused by sand flies can
be a challenging one but essential in that it failing to control it can make the
life of the living to be questionable. Through chemical control, vaccine and
medication ( even if the right vaccination hasn’t become available yet ) ,
chemical control (insecticide) we can help reduce the burden of these
diseases both on human and animal health.

3.3 Simulidae(black fly)

Black fly also known as buffalo gnats and turkey gnats belonging ti the family
simulidae are small,blood sucking insects that can be found in various region
around the world.black fly are small insects,1 to 5mm in length.they bite
during the day,only the female sucks the blood of animals nad humans.they
breed and live in all kinds of unpollunated water.Black flies can be annoying
biting pests, but none are known to transmit disease agents to humans in
the U. S. However, they transmit one parasitic nematode worm that infects
humans in other regions of the world. Onchocerca volvulus causes a
significant human disease known as onchocerciasis or “river blindness” in
equatorial Africa and mountainous regions of northern South America and
Central America.The bites of black flies cause different reactions in humans,
ranging from a small puncture wound where the original blood meal was
taken to a swelling that can be the size of a golf ball. Reactions to black fly
bites that collectively are known as “black fly fever” include headache,
nausea, fever, and swollen lymph nodes in the neck. In eastern North
America, only about six black fly species are known to feed on humans.
Several other species are attracted to humans, but they typically do not bite.
However, the non-biting species fly around the head and may crawl into the
ears, eyes, nose, or mouth, causing extreme annoyance to anyone engaged
in outdoor activities. Black flies can be found throughout most of the U. S.,
but their impact on outdoor activities varies depending on the specific region
and time of year. For example, in parts of the upper Midwest and the
Northeast, black fly biting can be so extreme, especially in late spring into
early summer, it may disrupt or prevent outdoor activities such as hiking,
fishing, and kayaking. Besides being a nuisance to humans, black flies can
pose a threat to livestock. They are capable of transmitting a number of
different disease agents to livestock, including protozoa and nematode
worms, none of which cause disease in humans. In addition to being vectors
of disease agents, black flies pose other threats to livestock. For example,
when numerous enough, black flies have caused suffocation by crawling into
the nose and throat of pastured animals. On rare occasions, black flies have
been known to cause exsanguination (death due to blood loss) from extreme
rates of biting. Saliva injected by biting black flies can cause a condition
known as “toxic shock” in livestock and poultry, which may result in death.

How Many Types of Black Flies Are There?

Black flies are true flies (Order Diptera) in the family Simuliidae, which
includes more than 1,700 species worldwide. In North America, 255 species
in 11 genera have been identified, but additional species remain to be
discovered and named. Very little is known about black flies in Indiana, and
there are no estimates of the number of species in the state. For
perspective, 12 species have been documented in Illinois, while over 30
species have been documented in both Minnesota and Wisconsin, where
black fly habitats are more abundant.

How Can Recognize an Adult Black Fly?

Black flies range in size from 5 to 15 mm, and they are relatively robust, with
an arched thoracic region.They have large compound eyes, short antennae,
and a pair of large, fan-shaped wings. Most species have a black body, but
yellow and even orange species exist.

What Is the Life Cycle of Black Flies?

Black flies undergo a type of development known as “complete
metamorphosis” (Figure 2). This means the last larval stage molts into a non-
feeding pupal stage that eventually transforms into a winged adult. After
taking a blood meal, females develop a single batch of 200-500 eggs. Most
species lay their eggs in or on flowing water, but some attach them to wet
surfaces such as blades of aquatic grasses.The length of time it takes an egg
to hatch varies greatly from species to species. Eggs of most species hatch in
4-30 days, but those of certain species may not hatch for a period of several
months or longer. The number of larval stages ranges from 4-9, with 7 being
the usual number. The duration of larval development ranges from 1-6
months, depending in part on water temperature and food supply. The life
cycle stage that passes though winter is the last stage larva attached
underwater to rocks, driftwood, and concrete surfaces such as dams and
sides of man-made channels

The pupal stage is formed the following spring or summer, typically in the
same site as the last stage larva, but may occur downstream following larval
“drift” with the current. Adults emerge from the pupal stage in 4-7 days and
can live for a few weeks. Adults of most species are active from mid-May to
July. The number of generations completed in one year varies among
species, with some having only one generation, but most species that are
major pests complete several generations per year.

Black fly larvae and pupae develop in flowing water, typically non-polluted
water with a high level of dissolved oxygen. Suitable aquatic habitats for
black fly larval development vary greatly and include large rivers, icy
mountain streams, trickling creeks, and waterfalls. Larvae of most species
typically are found in only one of these habitats.

Larvae remain attached to stationary objects in flowing water, held on by

silken threads extruded from glands located at the end of the bulbous
abdomen. Depending on species, mature larvae range from 5-15 mm in
length and may be brown, green, gray, or nearly black in color. They possess
a large head that bears two prominent structures known as “labral fans” that
project forward (see Figure 2). Labral fans are the primary feeding structures,
filtering organic matter or small invertebrates out of the water current.

Pupae remain attached to stationary objects in flowing water as well. They

typically are orange and appear mummy-like because the developing wings
and legs are tightly attached to the body. Pupae of many species produce a
delicate, silken “cocoon” of varying density, weave, and size that partially or

nearly entirely encloses them; other species produce hardly any cocoon at
all.

What Should Know About the Feeding Habits of Adult Black Flies?

It is estimated that females of 90% of the black fly species require a blood
meal for the development of eggs. Those of most species feed on mammals,
while others feed on birds. Females of some black fly species feed on only
one host, whereas others are known to feed on over 30 different host
species. No North American species feed exclusively on humans. Male black
flies are not attracted to humans, and their mouthparts are not capable of
biting.Females of most species of black flies feed during the day, usually
biting on the upper body and head. Unlike certain species of mosquitoes and
biting midges, black flies do not enter human structures to seek blood meals.

Do Humans Contribute to Black Fly Problems?

Human activities can lead to an increase in black fly numbers in an area.
Structures such as concrete dams and concrete-lined stream channels
provide excellent developmental sites for larvae and pupae of certain black
fly species. In addition, the restoration of polluted streams, especially in New
England, has increased the dissolved oxygen content of streams and created
suitable larval habitat for some of our most important pest species.

Veterinary Impact:

Black flies are transmitters of pathogens (nematodes, protozoans and

viruses) that can cause disease. Black fly females have very painful bites
and can exhibit nuisance swarms. Large numbers of black flies can cause
bird and livestock death as well as cause a stamped, trampling of young,
structure crashing and tumbling. Suffocation has been reported and blamed
for animal deaths by blocking respiratory passages. Excess blood loss can
be detrimental to the host’s health. Most deaths are caused by toxemia and
shock to the actual bites. Persistent attacks cause unruly host behavior,
weight loss, reduced egg and milk production, malnutrition of young animals,
dermatitis and epidermal necrosis, impotence, delayed pregnancy and
stress-related diseases.

Medical significance:

The significance of Simuliidae among medically important insects is twofold:

first, that this family includes all the carriers of human onchocerciasis (′river
blindness′), and secondly that the species include some of the world′s most
persistent and demoralizing man-biting insect pests. There are several areas
of the world, such as rural eastern Canada and southern New Zealand, where
simuliids are the most dreaded noxious arthropods even though they
transmit no human disease. In tropical medicine, however, it is the role of
simuliids as vectors of human onchocerciasis that makes headlines in the
fast-growing literature about this disease (Muller and Horsburgh, 1987:
bibliography). All vectors belong to Simulium. In this genus, as in other
Simuliidae and other biting Nematocera, only the females suck blood and
males are harmless. The hosts are birds and mammals (only warmblooded
vertebrates are bitten).
What Should Know About Controlling Black Flies?

Control of black flies is difficult, typically aimed at the larval stages, and
usually involves aerial applications of insecticides or physically altering the
habitat of pest species. The most effective control programs are conducted
by state agencies or by professional pest control companies contracted by
the state. Any effect is limited in duration, however, in large part because
females of pest species are capable of flying long distances from the larval
developmental site, and they soon re-infest treated areas.There is little that
an affected homeowner or person engaging in outdoor activities can do to
control black flies. For personal protection, it is best to avoid peak periods of
black fly activity. Information pertaining to the predicted “black fly season”
in a particular area often can be obtained by contacting a local Cooperative
Extension office. When venturing outdoors in infested areas, apply an insect
repellent containing DEET, wear protective clothing, and minimize openings
such as buttonholes through which black flies crawl in an attempt to feed.
Outdoor activities in heavily infested areas may require the wearing of fine-
mesh head nets, similar to those worn by beekeepers.

3.4 Ceratopogonidae(bitting midge)

Bitting midges are the vectors of parasitic round worms in several

genera,including Acanthocheilonema,Dipetalonema,mansonella and
Onchocera.midges constitute abitting nuisance in many parts of the
world,usually in the warmerseason.They can bite in swaems eslecially
targeting the faces, thus running many acampingtrip,tiny through.they are
skme speciess of midges can also transmit some fairly harmless species of
filarial worms in both Africa and south America.can be a nuisance to
campers, fishermen, hunters, hikers, gardeners, and others who spend time
outdoors during early morning and evenings, and even during the daytime
on cloudy days when winds are calm. They will readily bite humans; the bites
are irritating, painful, and can cause long-lasting painful lesions for some
people.A common observation upon experiencing a bite from this insect is
that something is biting, but the person suffering cannot see what it is. Biting
midges are sometimes incorrectly referred to as sand flies. Sand flies are
insects that belong to a different biological group and should not be confused
with the biting midges.

Distribution

There are over 4,000 species of biting midges in the Ceratopogonidae family,
and over 1,000 in just one genus, Culicoides. The distribution of midges in
the genus Culicoides is world-wide; 47

Species are known to occur in Florida. Species belonging to the genus

Leptoconops occur in the tropics, sub-tropics, the Caribbean, and some
coastal areas of southeast Florida.The natural habitats of biting midges vary
by species. Areas with substantial salt marsh habitat are major producers of
many biting midge species. Additional sources for some species, like the
bluetongue virus vector Culicoides sonorensis Wirth and Jones, include highly
organic soil that is wet but not underwater such as those found with high
manure loads in swine-, sheep- and cattle-farming operations. These insects
do not establish inside homes, apartments, or inside humans or other
animals.

Description

Immature Stages: The eggs can be cigar-, banana-, or sausage-shaped and

approximately 0.25 mm long. They are white when first laid but later turn
brown or black. The eggs are laid on moist soil and cannot withstand drying
out. Some species can lay up to 450 eggs per batch and as many as seven
batches in a lifespan. Eggs typically hatch within two to 10 days of being
laid; time to hatch is dependent on the species and temperatures.

The larvae are worm-like, creamy white, and approximately 2 to 5 mm long.

Larvae develop through four instars; the first instar larvae possess a
functional spine-bearing proleg. Pupal color can be pale yellow to light brown
to dark brown. They are 2 to 5 mm in length with an unsegmented
cephalothorax that has a pair of respiratory horns that may bear spines or
wrinkles. During this stage, the insects possess a spiny integument which
can be used to identify the fly to species level.

Adults: The adult no-see-ums are gray and less than 1/8-inch long. The two
wings possess dense hairs and give rise to pigmentation patterns. These
wing patterns are used by biologists to identify species. The large compound
eyes are more or less contiguous above the bases of the 15-segmented
antennae. The pedicel of the males’ antennae houses the Johnston’s organ.
The mouthparts are well-developed with cutting teeth on elongated
mandibles in the proboscis, adapted for blood-sucking in females, but not in
males. The thorax extends slightly over the head, and the abdomen is nine-
segmented and tapered at the end.

Life Cycle

Adults: Biting midges are holometabolous, progressing from egg to larva to

pupa, and finally to the adult stage. The complete cycle can occur in two to
six weeks, but is dependent on the species and environmental conditions.
The adults are most abundant near productive breeding sites, but will
disperse to mate and to feed. The mean distance for female flight is 2 km,
less than half of that distance for males.Male Culicoides typically emerge
before the females and are ready to mate when the female emerges from
the pupal stage. Mating typically occurs in flight when females fly into
swarms of males and the insects are oriented end to end with the ventral
parts of the genitalia in contact. Some species mate without swarming;
instead, the males go to hosts where the female is likely to feed on blood;
mating occurs when she finishes feeding.

Eggs: Males and females feed on nectar, but the females require blood for
their eggs to mature. The females will blood-feed primarily around dawn and
dusk; however, there are some species that prefer to feed during the day.
Some species are autogenous and therefore may produce the first batch of
viable eggs without a blood meal using reserves stored from the larval
period; blood meals are required for subsequent batches of eggs.

The number of eggs produced varies among species and size of bloodmeal.
For example, Culicoides furens (Poey) can lay 50 to 110 eggs per bloodmeal,
and C. Mississippiensis Hoffman, 25 to 50 eggs per bloodmeal. The adults
can live two to seven weeks in a laboratory setting, but only a few weeks
under natural conditions.

Larvae: Larvae require water, air and food and are not strictly aquatic or
terrestrial. They cannot develop without moisture. The larvae are present in
and around salt-marsh and mangrove swamps, on shores of streams and
ponds, and in muddy substrates. They feed on small organisms. Most species
cannot exist more than a few inches below the air-water interface.In the
tropics, the larval habitat of many species is in rotting fruit, bromeliads, and
other water-holding plants. Other larval habitats include mud, sand, and
debris at edges of ponds, lakes and springs, tree holes, and slime-covered
bark. The larval stage can last from two weeks to a year, depending on the
species, temperatures, and geographic area.While some larvae can develop
in wet manure-contaminated areas (Mullen 2002), they do not develop inside
the animal. The larvae also do not develop inside humans or other animals.

Pupae: The pupal stage typically lasts ~ two to three days.

Medical Significance

In the U.S., the biting midges are primarily a nuisance and the major medical
issue associated with Culicoides is allergic reactions to the bites. However,
like other blood feeding Diptera, Culicoides species are vectors of pathogens
that can cause disease in humans and animals. In Central and South
America, western and central Africa, and some Caribbean islands, biting
midges are the vectors of filarial worms in the genus Mansonella. These
parasites cause infection in humans that produces dermatitis and skin
lesions because the adult worms are located in the skin.

Biting midges, primarily the species Culicoides sonorensis, are responsible

for transmission of bluetongue virus to sheep and cattle in the U.S.
Bluetongue is a serious disease of ruminants. Bluetongue viruses are found
world-wide and are transmitted by different Culicoides species in different
regions. Many countries that are bluetongue free prohibit the movement of
livestock from bluetongue endemic regions. The annual economic damage in
lost trade is in the millions of dollars.Other animal disease causing pathogens
transmitted by the bite of infected biting midges include African
Horsesickness virus in equines that is confined primarily to Africa and
Epizootic Hemorrhagic Disease virus in ruminants found in North America
and principally having lethal effects on deer. Some equines experience
allergic reactions to the bites, resulting in equine allergic dermatitis, affecting
the withers, mane, tail and ears of the animal.

Management and Prevention

Historically, management methods included diking and drainage of

marshlands to reduce the habitats used by the immature stages. The
insecticide DDT was used to target the adult stage. Currently, larval habitats
are not targeted in control efforts because of the extensive amount of area
that the habitats may cover, some negative environmental impacts resulting
from changing water flow patterns of large areas, and the spotty spatial
distribution of larvae within a given habitat.Applications of insecticides
targeting the adult stage are not efficient. While this type of application may
kill biting midges active on a given night, they are continually dispersing
from the larval habitat and entering areas of human activity. It would require
insecticide applications on a daily basis in some areas, and this is not
efficient or environmentally sound. Many government agencies that provide
mosquito control services receive complaint calls about biting midges.
However, most of the programs are not mandated or allowed to respond by
providing control measures.On a large scale, removal trapping is conducted
using CO2 as an attractant to lure the biting midges to an insecticide-treated
target where they are killed. Research from the the University of Florida,
Institute of Food and Agricultural Sciences Florida Medical Entomology
Laboratory showed that biting midge populations were reduced in test areas
of Vero Beach and Boynton Beach, FL, and Castaway Cay, Bahamas. This
method of control is more appropriate for islands and specific inland areas
where pest control personnel can make a long term commitment to this
technique.Homeowners can install proper screening for windows and patios
to prevent no-see-ums from entering
 3.5 Tabanidae(Horsefly)

Introduction:Tabanidae are a family of diptera in the suborder Brachycera.

Within the Infraorder Tabanomorpha, there are some other hematophagous.
Some species of Rhagionidae and Atherecidae, called snipe flies, bite
humans, sometimes insistently, especially in the Palearctic and Nearctic
regions. The genus Suragina Walker, 1858 (Atherecidae) in Panama is
suspected of mechanical transmission of agents causing tuleremia and
anaplasmosis. Popularly, flies from this family are known as buttock, estrus,
gusano, gadfly, motuca, horsefly, and tavão. TheTabanidae females of these
insects present several adaptations related to the hematophagous habit,
which increase their potential as vectors of infectious agents. Among these
adaptations, anautogeny, telmophagy, the large volume of blood meal, the
long time of blood meal, and the interruption of feeding are highlighted. It
is emphasized that these insects are important because, in addition to
bothering humans by attacking them in search of a blood meal, they are
potential transmitters of diseases to animals and humans, being capable of
mechanically transporting viruses, bacteria, protozoa, and helminths,
through the fact that these pathogens adhere to the structure of the
proboscis.

Biology, Ecology and Distribution:Aquatic species are generally found buried

in the substrate. They can be large, reaching 6 cm. They have an elongated
appearance and with two fusiform ends, a very small head. Thick and rigid
cuticle, with a clearly segmented appearance, like short aligned cylinders.
Varied coloration, and may have a zebra pattern. The larvae are also
voracious predators, they feed on worms, mollusks, and insects, and may
have cannibalistic behavior. They can inflict a painful sting on humans,
often reported in rice fields. Pupation occurs out of water, in marginal lands.
Tabanidae are generally associated with rural or forested environments
and avoid enclosed spaces. The highest concentration of hematophagous
flies is found in locations that host high population densities of potential
guests. The events that lead to the mechanical transmission of pathogens
occur due to the fact that the insect starts feeding on an infected host and,
when it is interrupted, due to the pain felt, the insect is displaced and
moves to another host, transporting the agent inside the body or in the part
that comes into contact with the host, passing the agent throughA
cosmopolitan family, its range also includes the most remote islands of all
zoo-geographical regions on Earth, with the exception of Antarctica. The
greatest concentration of species occurs in tropical regions. Occur in
temperate, subtropical, and tropical locations, but hematopoiesis is absent
from Australia and South America .

Life Cycle: After oviposition, the egg takes 3 to 4 days for embryogenesis can
last up to 21 days. The female can lay 100 to 800 eggs in a single mass and
her eggs measure 1 to 3 mm in length. Horseflies often oviposit on leaves or
stems of emerging vegetation on the banks of lakes and streams. Some
species lay their eggs on tree bark hanging underwater, above the water line
on rocks, and also on dry soil and leaf litter.

Similar to all flies, horse and develop from egg to adult via a process of
“complete metamorphosis.” This means the last larval stage passes through
a non-feeding pupal stage, from which the adult eventually emerges.

The summarized life cycle of horsfly begins with the emergence of adults
from late spring into summer, depending on the species. Upon becoming
active, adults of both sexes feed on energy-rich sugars in nectar, plant sap,
or honey dew produced by sap-sucking insects such as aphids and scale
insects. Mating of the few species of that have been observed takes place in
flight. Females of some species are capable of developing an initial batch of
eggs without taking a blood meal (autogeny), otherwise blood is required for
the development of eggs. Females search for a place to lay a single mass of
eggs consisting of 100-800 eggs, depending on the species. Egg masses of
most species that have been studied are laid on the underside of leaves or
along the stems of emergent vegetation growing in wetlands. Hatching
occurs in approximately 2-3 days, and newly emerged larvae drop down into
water or saturated soil in which they feed and develop.
The sites in which horse fly larvae develop are known for only about a third
of the species in the U.S. Deer fly larvae appear to be limited to aquatic
habitats, including marshes, ponds, and streams. Developmental sites of
horse fly larvae are more varied. Larvae of most species are found in
freshwater and saltwater marshes, some in streams, some in moist forest
soils, and a few in moist decomposing wood. Larvae of all species of horse
flies that have been studied are predators. They feed primarily on other soft-
bodied animals such as insect larvae and worms, but larvae of some large
species of horse flies feed on small vertebrates, including tadpoles, frogs,
and toads. Horse fly larvae appear to possess a toxin in their saliva that is
involved in subduing their prey. Much less is known about the feeding
behavior of deer fly larvae, and there is no consensus as to whether they are
predators or scavengers.

The larval stages of horse range in number from 6-13, depending on the
species. The last larval stage passes through winter in the site in which it
developed and molts into a pupa the following spring. Most species complete
one generation per year. However, small species of deer flies can complete
2-3 generations per year and very large species of horse flies require 2-3
years in which to complete larval develop
 Medical-Veterinary and economic importance Horse flt is made up of
Diptera of medical-veterinary and economic importance, due to the
hematophagy carried out by the female, which causes blood spoliation and
transmission of agents pathogens. The wound opened by the bite allows
bacterial invasion and the emergence of myiasis. The economic importance
is related to the stripping and irritating action that Tabanidae cause mainly in
horses and cattle. They interfere with the animal’s feeding and rest,causing
loss of milk production and weight and due to myiasis, leather depreciation
The harmfulness of hematophagous Tabanidae manifests itself in three
aspects: Economic damage caused to the livestock sector, discomfort and
discomfort caused to people and pets, and transmission of pathogens. The
economic damage is due to the reduction in zootechnical production, due to
the stress caused by domestic animals systematically attacked by flies.
Persistent persistence in parts of the body that cannot be reached causes
stress, reduced appetite, weakening due to blood collection, and
transmission of more or less serious infections. They are a nuisance to
livestock and humans due to the insertion of the frontal style into the skin’s
epidermis.The main species of pathogenic bacteria mechanically transmitted
by Tabanidae in animals are Anaplasma marginale (Anaplasmataceae)
(carbuncle and malignant pustule), Bacillus anthracis (Bacillales) (carbuncle
and malignant pustule)), Pasteurella multocida (Gammaproteobacteria),
Francisella tularensis (Francisella), Clostridium chauvoei(Bacillaceae),
Brucella sp., Listeria monocytogenes (Bacillales), and Erysipelothrix
rhusiopathiae (Erysipelothrix), although only some of them have been
demonstrated experimentally. In addition to the ability to transmit bacteria,
and viruses (viruses equine infectious anemia, bovine leukemia, and swine
cholera) some species of Tabanidae are proven biological transmitters of
other etiological agents, such as the protozoan Trypanosoma vivax, a
parasite of cattle in South America.

Host

Horseflies feed on various vertebrate hosts, including domestic and wild

animals, such as cattle, camels, pigs, horses, rodents, reptiles, and birds.
Tabanids prefer donkeys, followed by cows, horses, and finally humans. The
search for the host involves olfactory attraction (CO2), the color of the
animal also interferes witattractiveness, for example, tabanids are more
attracted to dark horses than to light horses. Some hypotheses suggest that
this preference occurs due to the dark coat.Human blood does not have
exclusive characteristics that attract females. In fact, there are a number of
factors that contribute to a person being more attractive to mosquitoes. “In
general, CO2 from breathing, smell, perspiration, and temperature are
chemical and physical signals that attract females to feed [1-19].

Etiology The reason lies in the etiology of flies and the transmission
mechanism. The bite of flies is very painful and therefore immediately
attracts the attention of the victim, whose reaction can interrupt the insect’s
feeding and force it to move to another point or to another guest [1-20].To
complete a meal, a fly must generally practice more bites, and often on
different hosts,atashortdistance. This behavior facilitates the accidental and
mechanical transmission of pathogens with a mechanism similar to the
transmission of viruses transmitted by stylets by aphids on plants: the
pathogen does not establish any biological relationship with the carrier, it is
taken over by accidental contact of the mouthparts with the blood of an
infected host and transmitted immediately afterward with a puncture into a
healthy host [1-21].

Prevention and Control There are native beneficial insects that target
tabanids. Eggs are parasitized by such Hymenoptera families as
Trichogrammatidae, Scelionidae, and Chalcididae. Diapriidae and
Pteromalidae (Hymenoptera) and Bombyliidae and Tachinidae (Diptera)
parasitize the larvae and pupa. Tabanid adults are used as provisions for
nest-building wasps. Cattle egrets and killdeer are also tabanid feeders.
Preventive protection of the body with repellent products, available on the
market, is completely useless since flies are not attracted by smell, but by
heat. In fact, many governments have shown that the only effective tool for
fighting these flies is the trap. In the case of bites, specific products are used
to treat insect bites, such as antihistamines, and, in the case of more severe
and prolonged inflammation, the use of corticosteroids combined with
antibiotic