What does a locust look like?
Migratory (Asian) locust (Locusta migratoria)
The locust is a large insect with an elongated body 1–6 cm long, some species grow up to 14 cm. In appearance, the pest resembles a grasshopper .
The pest has a large, not very mobile head and large eyes. The insect's antennae are shorter than those of other members of the family. The chest is covered with dense hairs.
The color of the integument performs a camouflage function and depends on the environment and developmental phase. Single males and females are bright green, brown-olive, gray with small spots. In the gregarious form, all insects have the same color and are similar to each other.
Of the 6 legs, the front legs are the weakest, the hind legs are bent at the knees, they are longer than the middle and front legs. The insect's wings are translucent, covered with hard elytra and invisible when folded.
The locust has a powerful jaw, which allows it to chew not only soft, but also hard food . The pest gnaws out leaves and stems with its upper mandibles and crushes them with its lower mandibles. The insect does not feed on flower nectar.
There are special notches on the thighs of males, and thickenings on the elytra. When they rub in flight, the insect makes specific creaking sounds. When a swarm of locusts flies, these sounds turn into a strong roar , similar in power to thunder.
Insect eggs are 6–8 mm long and resemble grains in color and shape. The larvae look like adult locusts. The color of the gregarious form is variegated, single larvae are most often green.
How to recognize locusts
Some types of locusts are very similar to grasshoppers. However, there are a number of differences that will help you recognize the insect:
- unlike the grasshopper, the locust has wings;
- the length of the legs and antennae of the locust is less than that of the grasshopper;
- Locust activity occurs during the day, and grasshopper activity occurs at night.
Grasshoppers are predators by nature, but they do not harm crops. Locusts, on the contrary, eat grain crops, and only occasionally a weaker individual from the swarm to obtain liquid.
Features of the life of a pest
Italian locust (Calliptamus italicus)
Locusts are widespread everywhere, with the exception of cold climate zones. The family has over 10,000 species. In our country, the migratory (Asian) locust (Locusta migratoria) , the Italian locust (Calliptamus italicus) the Moroccan locust (Dociostaurus maroccanus) in the south . Some species live near rivers in dense thickets of grass, others in arid and rocky areas overgrown with sparse bushes and grass.
In adult insects, there are 2 stages: solitary and gregarious. Single individuals (fillies) live separately, they are inactive and feed on moderate plant foods. One such locust eats 300 g of food during its life.
Having gathered in a flock, the insect becomes voracious . It devastates grain fields and gardens and eats its weakened relatives.
The development of the pest is incomplete. After fertilization in the summer, the female lays 50–150 eggs, protected by an egg capsule, . Depending on the species, the female lays 1–18 egg capsules during her life.
The walls of the cocoon are thin and soft, consisting of a mixture of brown insect secretions and particles of earth. After the end of oviposition, the adults die, and the eggs overwinter in a capsule. In the spring, the eggs burst and larvae emerge from them. They look like adult insects, but without wings.
The larva develops in 30–50 days, in the southern regions it takes 14–16 days, and during this time 5 instars pass, accompanied by molting. After the last molt, the locusts develop wings. Depending on the species, the insect lives 8–24 months.
Biological characteristics of locusts
To effectively fight the enemy, you need to know him “in person” - habits, tastes, methods of reproduction. What are locusts?
A locust, or locust, is a gregarious insect belonging to the order Orthoptera and the family Acrididae. On the territory of the former Soviet Union, there are mainly two species: the Italian Locust and the Asian, or migratory, Locust. The latter is considered the most voracious and dangerous.
The filly is a rather large insect, growing up to 6 cm in length. Its color can range from gray to olive-brown with small spots. It constantly lives in the floodplains of many large rivers - the Volga, Don, Terek.
In appearance, the locust is very similar to the common grasshopper, of which it is a relative. They are even often confused, especially where locust infestations are extremely rare. They differ only in the size of their mustache and the presence of wings, with the help of which they can not only jump, but also make short flights. In their normal state, these insects lead a completely sedentary lifestyle, which can last as long as desired. But there comes a time when they suddenly begin to gather in flocks - the so-called swarms, which go in search of a new habitat.
Locust larvae emerge from eggs in early May. Outwardly, they are very similar to adult insects and differ only in the absence of reproductive organs and underdeveloped wings. Under normal conditions, growing up, these little ones become just solitary fillies, living sedentary lives. What makes them change their usual lifestyle?
The locust is a unique insect, having two alternative development programs laid down by nature at the genetic level. The cause of disaster for others is that which protects against overpopulation. Without it, the population would very quickly die from lack of food.
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It's actually quite simple. While the number of fillies is not large, they behave like ordinary grasshoppers. Unless they jump higher and crack louder. The damage they cause to plants is also no more than from their smaller counterparts. But as soon as the number begins to reach its maximum size, when young individuals are in direct visibility of each other, protection is triggered. Development is turning in a different direction. Instead of the usual ones, larger individuals grow, having elongated wings and a different color, which appears after the final molt. They are noticeably more active and have a need to accumulate in some place. As a result, insects gather in huge flocks and go to explore new territories - where there is enough food and the environment is favorable for reproduction.
It turns out that in order to prevent locust invasions, it is enough to deprive them of the ability to reproduce quickly. If individual fillies do not constantly collide with and see each other, the protective program will not work and swarms of insects will not form.
On the other hand, while the fillies are in the development stage and live alone, not accumulating in one place, it is quite difficult to find them. They will begin to move to the neighboring territory as adults. It will be quite easy to detect them, but to destroy them will be much more difficult.
Why do the locusts come?
Moroccan locust (Dociostaurus maroccanus)
For a long time, the reasons for the appearance of locusts were not clear to people. Why in some years did safe and modest single individuals gather in flocks of millions and turn into pests of mass destruction over thousands of square kilometers?
At first it was believed that such temporary mutations occur during dry seasons, when most vegetation quickly burns out and there is less food for the insect. But the facts contradict this. The formation of a flock occurs not only in hot years and when there is an abundance of food.
Scientists' latest discovery is that hordes of locusts appear not due to hunger, but due to a lack of protein in food . This leads to cannibalism among them. Some insects attack their protein-rich relatives.
Fearing being eaten, single individuals (fillies) gather together. The gregarious form most often forms in river floodplains. Seeing many relatives nearby, a “marching” program is launched in the insect’s body.
The offspring from the laid eggs appear already programmed to search for food . For about 2 weeks after birth, young insects remain in one place. The signal for migration is population density. As soon as a critical mass accumulates and all the vegetation around is eaten, the army of the pest goes in search of a better habitat.
At first, insects walk on foot, since there are no wings yet. They move quickly in orderly rows, crossing even wide rivers. Many walking locusts die in this case, but this decline does not seriously affect the herd. After several molts, the pest increases in size - muscles and wings grow. They become larger and lighter than single individuals.
The locusts are becoming more aggressive and voracious. Scientists believe that solar activity also affects the aggressiveness of the pest. Having spread its wings and risen upward, the locust then moves through the air.
The flock flies at a speed of 10–15 km per hour and can cover 80–120 km per day . The pest eats everything in its path, but as soon as they accumulate a sufficient supply of protein, the locusts again turn into peaceful insects, and the formidable swarm disappears.
Harm of locusts
Knowing how serious the consequences of insect bites are, it becomes quite logical to ask whether locusts are dangerous to humans. Unlike its fellow grasshopper, locusts are not capable of biting. But it causes enormous harm. Locusts typically make creaking sounds that resemble crackling sounds. Even with a small number of individuals on the site, a fair amount of noise is produced, which irritates both humans and animals. As a result, the latter begin to show concern.
But still, the main factor why locusts are dangerous is the destruction of crops. Priority is given to cereals and melons. Not a trace remains of the plants; the locusts devour them from roots to tips of leaves.
Insects of all ages have a herd reflex. As soon as they see their own kind, they begin to unite. Under favorable conditions and a good food supply, they multiply rapidly and eventually form a powerful flock. Its population can be in the thousands, millions and even billions of individuals. Such a horde destroys everything in its path, leaving flowering fields as wastelands. Insects eat grape plantations, grain and vegetable fields, thatched roofs of houses, reeds, and orchards. It is interesting that during long migrations the flock does not shun cannibalism. The tribe immediately absorbs weakened individuals.
The most severe locust attack in Russia over the past 30 years was recorded in 2015. Hordes of harmful insects destroyed 30 thousand hectares in Bashkiria, 10 thousand in Chechnya, 35 thousand in the Astrakhan region. The Stavropol and Orenburg regions were affected. The total area of damaged land is equal to the territory of Romania.
According to some experts, temperatures above 28°C cause the Asian locust, which lives in Crimea and the Caucasus, to become more active. Suffering from a lack of moisture, individuals try to replenish it, thereby destroying vegetation. If global warming continues at the same rate as now, then in 30-40 years hordes of locusts will reach Karelia.
What plants does the pest attack?
Locusts are omnivorous . Moving through the fields of large farms, it destroys grain plantings: wheat, rye, oats, barley . It gnaws the ears and eats unripe grains.
Damages crops of rice, millet, sorghum, corn, buckwheat, sunflower, hops, flax, soybeans . Swarms of locusts attack pastures and haylands where alfalfa, clover and other grasses grow.
On farm and private plots, locusts feed on potatoes, beets, cabbage, rutabaga, pumpkins and legumes . The pest can cope with young fruit trees, forest trees and shrubs . Locusts eat their bark.
Methods of locust control in large farms
Not only farmers themselves, but also government services are involved in the fight against locusts. In the regions, special centers monitor locusts, make forecasts for the spread of the pest, determine affected areas and control methods . Their task also includes mandatory informing agricultural producers about the results obtained.
Farmers, for their part, must regularly assess the phytosanitary condition of their fields. Currently, the most effective and fastest methods of control in large farms is the use of pesticides .
Spraying is carried out from small aircraft at low altitude or on the ground using wide-cover sprayers . It is important to carry out these treatments on time - until the locusts take wing. Adults are resistant to poisons, and larvae of 3–4 instars can be successfully destroyed with insecticides. Large farms use pesticides: Image, Dimilin, Gladiator KE , etc. Additional control measures are autumn harrowing, cultivation and peeling of the soil .
How to destroy locusts in the garden
While researchers are busy in laboratories, the locusts do not sleep. And if the average gardener is not yet able to cope with the invasion of a multimillion-dollar flock, he is quite capable of eradicating rare settlers.
Reminder on how to deal with locusts:
- Having discovered an adult or oviposition, immediately destroy it mechanically.
- Dig the soil deeply at the end of summer to find and neutralize locust egg capsules. During the same period, you can burn plant residues and stubble. This will eliminate locust eggs that are on the soil surface. But as a rule, most egg capsules are located at a depth of 5-7 cm, so burning will not help completely get rid of egg-laying eggs.
- Chemical soil treatment is most effective before sowing seeds and planting plants. To do this, use products from the group of pyrethroids: “Taran”, “Caesar”, “Karate”, “Fastak”. The working solution is prepared in accordance with the instructions. If the treatment is carried out at the end of May, June, when the locust larvae are 2 or 3 instars, organophosphorus preparations are additionally added to the solution.
- During the period of invasions, imidacloprid-based products are used to protect plants: “Image”, “Tanker”.
- In late autumn, agrotechnical measures are carried out, including plowing and cultivation.
To combat locusts, natural enemies are also used: reptiles, blister beetles, birds.
How to deal with locusts in your area
Chemical and biological drugs
Karate Zeon
A pyrethroid insecticide quickly penetrates the insect's integument and acts on its nervous system. The feeding activity of the pest is blocked, paralysis and death of the locusts occurs.
To combat the pest, solutions of different concentrations are prepared. For single locusts and younger larvae, 7 ml of the drug is diluted in 10–20 liters of water. For older larvae, you will need 10 ml of product per 10 liters of water.
Clothiamet
New generation enteric-contact insecticide. Used during mass emergence of locust larvae. First, 0.5 g of the drug is thoroughly mixed with 2–3 liters of water, then the liquid is added to a volume of 10 liters.
Mospilan
The drug, without a toxic odor, has a nerve-paralytic effect on the pest. One treatment protects plants for 30 days. For spraying, 2.5 g of powder is dissolved in 1 liter of water, then 8–10 liters of water are added to the concentrate.
Metarizin
Biological product based on an entomopathogenic fungus. It grows into the body of the larvae, causing mycosis and death of the pest. Safe for humans and soil. Protects against locusts for several years.
It is recommended to apply the drug to damp soil during digging: 5–10 g per 1 sq.m. Metarizin can be added to irrigation water, sprayed on the soil, or mixed with fertilizers.
Traditional methods
Herbal infusions and mixtures will not help cope with the pest . A non-chemical method of control is manual collection of insects . This is suitable for small areas.
You can catch adult insects using ultraviolet traps . 2-3 light bulbs are attached to the trap structure. They are turned on during the day during the summer of insects. Locusts have good eyesight and ultraviolet light will attract its attention. Large containers of water are placed under the lamps, where the insects will fall.
Prevention
- The soil on the site must be dug up in spring and late autumn. This is how egg capsules are discovered and burned.
- Weeds are regularly destroyed in your garden and surrounding areas. The perimeter of the site is mowed and the weeds are not allowed to grow.
- The pest has many natural enemies among animals; they should be used as helpers. Locust is a nutritious, high-protein food for birds. It is readily eaten by starlings, crows, sparrows and other birds. Poultry also loves it: chickens, ducks and turkeys. The insect's enemies are also frogs and blister beetles.
Modern methods help predict the appearance of the pest, and the latest drugs quickly deal with it. Both in agricultural enterprises and in small summer cottages, you need to fight insects together with your neighbors. Only joint efforts will contain the locust numbers.
You will learn more about the insect pest from the video.
