Insects are the most diverse in terms of species composition of a class of animals that differ from each other in various ways. One of them is the type of transformation in the process of individual development.
Types of Insect Development
In all representatives of this class, a newborn individual is significantly different from adults. This type of development is called indirect. But in different groups of insects, it can occur with complete and incomplete transformation. Often, the larva and the adult individual differ not only in appearance, but also in the way they live. So, the butterfly larva feeds on green foliage, and the adult individual on floral nectar. Insects, which are characterized by incomplete transformation, lead the same way of life at all stages of development.
The term "transformation" itself means the presence of a larval stage in the process of individual development. Only ontogenesis of insects can occur in different ways.
Complete and incomplete transformation
In some insects, a larva hatches from an egg, in general terms resembling an adult - an adult. These are individuals with incomplete transformation. Their larvae are immediately capable of self-feeding, growth and molting, after the last of which they turn into adult insects. For example, incomplete transformation is characteristic of cockroaches. In the course of their development, they go through the following stages: egg, larva, adult.
Various types of beetles, butterflies, bees, bumblebees, ants and mosquitoes develop with complete transformation. Their larvae are significantly visually different from adult individuals. This primarily consists in the absence of wings, complex eyes. In addition, the larvae have shortened or missing limbs, and the oral apparatus is modified. After this stage, in insects with complete conversion pupation occurs. This process is very important. At the pupal stage, insects do not feed and practically do not move, which ensures the experience of adverse conditions. The duration of this period varies from 6 days to several months, depending on the species. In the photo you can see the larvae of the Colorado potato beetle, which, you see, barely resemble an adult.
Incomplete Insects
This group of animals includes representatives of the orders Termites, Orthoptera, Lice, Bedbugs, Praying Mantis, etc. Incomplete transformation means that the appearance and lifestyle of the newly emerged larvae are no different from adults. For example, in all parasitic bugs at different stages, the body is flattened, and the wings are absent. And termites have very thin, and sometimes transparent, covers that persist throughout life.
Orthoptera squad
Incomplete transformation is also a hallmark of all representatives of the Orthoptera squad. They are quite diverse: in total in nature there are more than 20 thousand species. Orthoptera is easily distinguished from other insects by the leathery hind elytra. During the flight they unfold fan-shaped. This device serves as reliable protection for thin webbed wings. Also characteristic features of this detachment are the gnawing mouth apparatus and hind legs, capable of jumping sufficiently high and long in relation to the size of the insect itself.
Incomplete transformation is characteristic of all Orthoptera. These are well-known grasshoppers. And the owners of gardens and kitchen gardens will probably remember the bear, which is a pest of the root systems of many cultivated plants. This insect has well-developed digging legs, with the help of which it makes long passages in the soil.
Locusts are also direct-winged herbivorous insects with indirect development. They pose a significant danger to agriculture, because when flying from place to place, they destroy everything in its path. And above all - the crop of cultivated plants, as they are very voracious.
Lice Squad
Surely many recognized the wingless parasitic insects depicted in the photograph. These are lice. Attaching to the hairs on the host's body with the help of the moving claws of each leg, they feed on his blood. To do this, lice have a characteristic piercing-sucking-type mouth apparatus.
These insects are very dangerous. Human louse is a carrier of diseases such as relapsing fever and typhus. For a long time, drugs against them did not exist. During severe epidemics over the past century, about 30 million people have died from typhoid. To avoid becoming infected with lice, you need to adhere to basic hygiene rules: do not use other people's combs, towels, clothes, or headgear.
Thus, incomplete transformation is one of the types of indirect development of insects in which the pupal stage is absent, and the larva is morphologically and anatomically similar to an adult - an adult.