An insect with complete transformation (with metamorphosis) goes through four stages in its development: an egg – a larva – a pupa – an adult insect (imago).
Groups of insects with complete transformation: butterflies (lepidoptera), beetles (coleoptera), dipterans, hymenoptera, fleas.
Most insect species develop with complete transformation. In insects with complete transformation (butterflies, beetles, flies, wasps, ants), the larvae do not at all look like adults. They do not have compound eyes (there are only simple eyes, or the organs of vision are completely absent); antennae are often absent, there are no wings; the body is most often worm-like (for example, butterfly caterpillars).
In insects with complete transformation, the larvae often live in completely different places and feed on a different food than adult insects. This eliminates competition between different stages of the same species.
Insect larvae with complete transformation molt several times, grow and, having reached their maximum size, turn into a pupa. The pupa is usually motionless. An adult insect emerges from the pupa.
Watch the video that shows the emergence of the Monarch butterfly from the chrysalis.
Order Butterflies, or Lepidoptera
Butterflies differ from other insects mainly in two features: a scaly cover of the wings and a sucking mouth apparatus, coiled in a spiral.
Butterflies are called Lepidoptera because they have small chitinous scales on their wings. They refract incident light, creating a whimsical play of shades.
Coloring the wings of butterflies helps them recognize each other, disguises in the grass and on the bark of trees, or warns enemies that the butterfly is inedible.
The sucking mouth apparatus in butterflies is a proboscis coiled into a spiral. Butterflies feed on the nectar of flowers.
The larvae of butterflies (caterpillars) have a gnawing mouth apparatus, they feed on plant tissues (most often).
When pupating, the caterpillars of some butterflies secrete silk threads. The silk thread is secreted by a special silk-separating gland located on the lower lip of the caterpillar.
Silkworms are bred by people to obtain silk fabrics (this is the only insect that does not occur in nature in the wild).
Detachment Beetles, or Coleoptera
Representatives of this group have dense rigid elytra covering the second pair of leathery wings, with the help of which they fly. The mouth apparatus is gnawing.
Among the beetles there are many herbivores, there are predators and carrion eaters.
Beetles live in the ground-air environment (on plants, the surface of the earth, in the soil) and in water.
Beetle larvae are both very mobile predators, living openly, and inactive, worm-like, living in shelters and feeding on plants, fungi, and sometimes decaying remains of organisms.
These insects have only one pair of wings. The second pair is greatly reduced and serves to stabilize the flight. This group includes mosquitoes and flies. They have a piercing-sucking or licking mouth apparatus. Some dipterans feed on pollen and nectar of flowers (sirfid flies), there are predators (ktyri) and bloodsuckers (mosquitoes, biting midges, midges, horseflies). Their larvae live in the decaying remains of cesspools, composts (house flies), in water (mosquitoes and midges) or lead a wandering lifestyle and prey on small insects.
The group includes such well-known insects as bumblebees, wasps, bees, ants, sawflies, wasps. They have two pairs of membranous wings (some have no wings).
The Flea order includes parasitic insects that suck blood from rodents, other mammals and humans. They have a piercing-sucking mouth apparatus and no wings. Fleas have hopping hind legs. Fleas are extremely dangerous because they are carriers of the plague pathogens.