The life cycle of the louse has three stages: egg, nymph, and adult.

Eggs: Nits are head lice eggs. They are hard to see and are often confused for dandruff or
hair spray droplets. Nits are laid by the adult female and are cemented at the base of the
hair shaft nearest the scalp . They are 0.8 mm by 0.3 mm, oval and usually yellow to white.
Nits take about 1 week to hatch (range 6 to 9 days). Viable eggs are usually located within
6 mm of the scalp.

Nymphs: The egg hatches to release a nymph  . The nit shell then becomes a more visible
dull yellow and remains attached to the hair shaft. The nymph looks like an adult head
louse, but is about the size of a pinhead. Nymphs mature after three molts and become
adults about 7 days after hatching.

Adults: The adult louse is about the size of a sesame seed, has 6 legs (each with claws),
and is tan to grayish-white  . In persons with dark hair, the adult louse will appear darker.
Females are usually larger than males and can lay up to 8 nits per day. Adult lice can live up
to 30 days on a person’s head. To live, adult lice need to feed on blood several times daily.
Without blood meals, the louse will die within 1 to 2 days off the host.

APHIDS

In October the females lay eggs usually on the stems of trees or shrubs. The eggs are black, with thick
shells and can withstand extremes of temperature. It is in the egg form only that aphids pass the
winter. In March the eggs hatch out into wingless female nymphs which are similar to the adults, with
three pairs of legs, compound eyes, antennae, etc. There is no larval or pupal stage comparable to
those of the butterfly, but with successive moults and continuous growth the nymphs become mature
females. No males are hatched at all.
The aphid life cycle has three stages: egg, nymph and adult. Eggs overwinter on the host plant and a generation of
females hatch in the spring. Within ten days of being born, the female aphid can give birth asexually (without
mating) to a second generation of females. This process can continue throughout the summer allowing aphid
populations to reach high numbers very quickly. In the fall, winged males are produced to mate with remaining
females. The eggs which are produced from this union overwinter. The following spring, the cycle continues.

The cicada life cycle has three stages: eggs, nymphs, and adults. Female cicadas
can lay up to 400 eggs  divided among dozens of sites—generally in twigs and
branches. After six to 10 weeks, young cicada nymphs hatch from their eggs and
dig themselves into the ground to suck the liquids of plant roots. They spend
their entire developmental period in these underground burrows before molting
their shells and surfacing as adults to mate and lay eggs.
Cicadas begin life as a rice-shaped egg, which the female deposits in a groove she makes in a tree
limb, using her ovipositor. The groove provides shelter and exposes the tree fluids, which the young
cicadas feed on. These grooves can kill small branches. When the branches die and the leaves turn
brown, it is called flagging.
Once the cicada hatches from the egg it will begin to feed on the tree fluids. At this point, it looks like a
termite or small white ant. Once the young cicada is ready, it crawls from the groove and falls to the
ground where it will dig until it finds roots to feed on. It will typically start with smaller grass roots and
work its way up to the roots of its host tree. The cicada will stay underground from 2 to 17 years
depending on the species. Cicadas are active underground, tunneling, and feeding, and not sleeping
or hibernating as commonly thought.
After the long 2 to 17 years, cicadas emerge from the ground as nymphs. Nymphs climb the nearest
available vertical surface (usually a plant) and begin to shed their nymph exoskeleton. Free of their old
skin, their wings will inflate with fluid (haemolymph) and their adult skin will harden (sclerotize). Once
their new wings and body are ready, they can begin their brief adult life.

Aphid eggs are variously elliptical to chisel-shaped, and either glued to a support or
attached by a thread (as are adelgid eggs, and those of Pineus pini). The first image
(below) shows Adelges cooleyi eggs attached by threads to a needle of Douglas fir,
albeit hanging beneath the wax wool produced by their mother. The second image is a
micrograph of a Pineus pini egg, showing its attachment thread. This arrangement
presumably helps to protect the eggs from predators such as mites.

The life cycle of a dragonfly starts with eggs. After breeding, a female dragonfly selects a pond
or marsh in which to lay her eggs. Dragonfly eggs are only laid in still water, as eggs laid in
quickly moving water will wash into fish-feeding areas.

Female dragonflies lay their eggs on submerged aquatic plants, mud banks submerged in water,
or if they can't find a better spot, directly in the water. Depending on the species, a female can
lay hundreds or thousands of eggs during her lifespan.

When dragonflies hatch they are called nymphs. Dragonfly nymphs are voracious predators that
have no resemblance to their adult forms. They molt (shed their skin) up to 12 times, depending
on the species, and can spend as long as four years as nymphs.

Dragonflies living in tropical regions spend less time in the nymph form while dragonflies living in
temperate regions will spend longer as nymphs as the onset of winter delays maturation.

Dragonfly nymphs are aquatic, living in ponds and marshes until emerging to molt for one final
time. During the final molting, the nymph's skin splits and the nymph emerges as an adult
dragonfly. Dragonfly nymphs are hemimetabolous, meaning they don't form a cocoon or pupate
before emerging as an adult.

After the final molt from nymph to adult, occurring in late spring or early summer in temperate
regions and at any time of the year in tropical regions, most dragonfly species spend the next
month fully maturing. Their gonads (sex organs) finish developing, their color becomes brighter
with their final markings emerging and they disperse, sometimes hundreds of miles, from the
pond or marsh where they developed.
Adult dragonflies are also voracious predators eating small insects, primarily mosquitoes and
flies, which they catch while flying. Dragonflies can hover, fly backwards, forwards and
sideways.

Once fully developed, a female dragonfly can mate with several males before she is ready to lay
her eggs. Both female and male dragonflies only live two to four months as adults before dying.