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Among the two million species of insects that inhabit the Earth, there are those that are capable of becoming a true natural disaster. One of them, the Asiatic locust, belongs to the Orthoptera order.
Grasshoppers, briskly jumping on meadow grasses, are related to locusts, however, unlike them, they never breed in huge numbers and do not become a serious threat to all the surrounding greenery.
REFERENCE! The easiest way to distinguish a locust from a grasshopper is by the length of the antennae: in grasshoppers, they are longer than the body, and in locusts, shorter than the head.
Insects belonging to the species Asiatic Migratory Locust (Locusta migratoria) live in Europe and Asia Minor, in North China and North Africa, in Korea. On the territory of Russia and the CIS countries, these Orthoptera gravitate towards the south of the European part, the Caucasus, Central Asia, Kazakhstan and the southern regions of Western Siberia.
In a temperate climate zone, an insectleaves overwintering clutches of eggs in loose, sandy, sufficiently moist soil... Ideal nurseries for future generations of these insects are river floodplains and the banks of reservoirs covered with thickets of reeds and sedges.
Accordingly, on the territory of Russia and neighboring countries, especially large foci of locust breeding are located in the deltas of the rivers flowing into the Black, Caspian, Aral Seas and Lake Balkhash, as well as in the Danube delta.
In the spring, if the clutch is not dry and flooded by a prolonged flood, miniature locust larvae emerge from underground egg-pods, bypassing the pupal stage, which have a shape and structure similar to an adult insect. Young growth rapidly develops and grows, passing several molts.
In "well-fed" years, when these Orthoptera can find abundant plant food rich in protein, they from spring to late autumn live in a solitary form of "filly" up to 4-5 cm long... This “peaceful” form is green or yellowish-green in color, is inactive, has a pronounced “hump” on the back and feeds on wild grasses - mainly reeds and wheatgrass.
However, harmless "filly" can acquire a completely different look, forming herd form, which is so different from a single species that for a long time it was attributed to a special, separate species.
Periodically, at intervals of about 10-12 years, in especially dry and hot years, the Asian migratory locust reproduces in extreme quantities... Then the larvae, which have not yet grown wings, increase in size up to 6.5 cm.
They straighten their stooped backs, instead of a cheerful green color, they are covered with a formidable rusty-mourning camouflage and begin to march in formation, gathering in dense columns - bands that destroy everything growing, juicy and green on their way.
After the fourth or fifth molt, acquiring long, straight wings and the ability to fly for up to 12 hours without a break, they turn into a real biblical horror, the eighth Egyptian execution - a cloud of insects, independently moving at a distance of up to 300 km, and with a tailwind, overcoming a thousand-kilometer distance.
REFERENCE! During the day, a small flock of a million "heads", having landed, destroys 20 tons of vegetation.
A horde of billions of locusts in flight makes a thunderous sound, composed of the crackling of a myriad of thin mesh wings, and when landing breaks off tree branches with its weight.
Both walking bands and flying flocks eat crops - wheat and rye, barley, oats, corn, rice, sorghum and millet. Alfalfa and clover fields, hayfields and pastures are devastated, forest trees, fruit seedlings and berry bushes are deprived of their foliage.
Destroy the growth of legumes and melons, foliage of potatoes and root crops, planting hops, tobacco, grapes, flax and cotton, oilseeds. The massive invasion of the Asian migratory locust is a real disaster for any agricultural economy.
Forms of locust development in pictures:
Solitary Peace Form
Young Asian Locust without wings
In order to prevent agricultural disasters, insects are monitored in the breeding areas at different stages of development of the migratory locust.
Such accounting allows you to predict the appearance of a herd form and to use insecticides in the phase of population growth - including, to carry out barrier treatment of nesting sites.
The biological enemies of locusts are insectivorous mammals and birds (especially starlings), as well as some fungi pathogenic for orthoptera.
Agrotechnical prevention of the growth in the number of the Asian locust is:
- Drainage of floodplains of rivers and lakes using them for agricultural planting.
- Improvement of pastures mass sowing of forage grasses. The soil, densely rooted, becomes unsuitable for laying eggs.
- Deep plowing of areasinfested with locusts, with overturning of the earth layer and harrowing.
- Spring disc loosening on roadsides and the slopes of irrigation canals.
Asian migratory locust (family name - locust), type of development - indirect. During the period of mass reproduction, this pest poses a real threat to all agricultural crops.
An increase in the number of these insects can be prevented by agrotechnical and biological prevention, as well as by timely treatment of breeding centers with insecticides.
How locusts eat: