Each order of insects contains pests of agricultural plants.
Orthoptera squad (locusts and bears)
The Asian or migratory locust is especially dangerous. From its invasion, bare earth with eaten plants remains in the fields. The main breeding grounds for locusts are reed beds of large southern rivers. The larvae hatch from their eggs in spring, molt 4–5 times, while the larvae develop wings, and the locust flies away from their nests for great distances.
From the bear, the common bear is widespread. She lives in the soil. To lay eggs at a depth of 10–20 cm, the female makes a nest. When arranging nests and numerous passages, it gnaws at the roots and underground parts of the stems, eats up tubers, roots, seeds.
Homoptera squad (aphids)
Among the Homoptera, there are many insect pests: aphids, whiteflies, scale insects, scale insects, leaf flies, gall midges. Aphids are especially harmful to human agricultural activities.
Aphids (cabbage, melon, beet, pea) suck the juices from young shoots and leaves. Plants are severely stunted or dry out.
Aphids multiply rapidly. They have several generations over the summer.
Order Hemiptera (Bedbugs)
Both adults and bug larvae damage cereals, especially wheat. Piercing not yet ripe caryopses, the bug introduces saliva into them and sucks the dissolved contents.
Squad Coleoptera (Beetles)
Of the coleoptera, the greatest harm to agriculture is caused by the beet weevil, the Colorado potato beetle, and click beetles.
The beet weevil can kill up to 10 young plants per day. It brings the greatest harm during the period of beet growth. At this time, the female weevil lays eggs in the soil near the beet seedlings. The worm-like larvae feed on beet roots.
The Colorado potato beetle, a dangerous pest of potatoes, was brought to Europe from America along with potatoes. During the summer, two to three generations of beetles develop. Both adult beetles and their larvae feed on potato leaves.
The larvae of click beetles – wireworms – damage potato tubers, carrots, and beets.
Order Lepidoptera (Butterflies)
Caterpillars of the cabbage butterfly feed on the leaves of cabbage and other cruciferous plants, leaving only the largest veins. They keep openly: birds do not eat them because of the poisonous liquid they release.
Caterpillars of winter moths live in the soil, where they destroy the sown seeds and emerging seedlings, gnaw the stems of plants at the soil level, and then, crawling to the surface, eat the leaves.
Onion fly females lay their eggs on lumps of soil near onions or garlic. The larvae emerging from the eggs are drilled into the bulbs and leaves, eat out the passages in them.
Cabbage and carrot flies bring similar harm.