Locust is the most dangerous pest of the plant world. Insect locust: appearance, species, method of reproduction, nutrition

(living mainly in the south of Russia), Australian, Moroccan.

Stages of development of the locust

Members of the locust family indirect development of the embryo.

The development of the embryo in the world of animals and insects is of 2 types:

• direct when a child differs from his parents only in a smaller size and underdevelopment of organs (mammals);
• indirect when a newborn child (larva) differs in appearance from its parents.

In insects, the second type of development is also divided into 2 types:

• complete metamorphosis(transformation), when females lay eggs, a larva hatches, grows until a certain period, then there is a transformation into a chrysalis. This "doll" period is called the resting stage. Inside the pupa, absolutely all vital organs are rebuilt and an adult insect is formed. Such a metamorphosis is characteristic of butterflies, flies, wasps,;
• incomplete metamorphosis: the absence of a "pupal stage", the larva immediately takes the form of an adult insect in the process of several molts. This metamorphosis is characteristic of grasshoppers and locusts.

Therefore, the statement that the locust has a chrysalis is incorrect and is simply a delusion.

Locust breeding

How do locusts reproduce? The process is going on in the following way: the male secretes and distributes a special hormonal substance around him which attracts the female. Then he jumps on his partner, as if saddling her from above and tightly attaches to her with his genitals.

Then he deposits a spermatophore(sac with spermatozoa) to the base of the ovipositor (the organ of the female, with strong teeth, which serves as a kind of gimlet that allows you to tear the ground and bury the egg) of the female. Mating usually lasts quite a long time: from 2 to 14 hours.

Fertilized female finds wet ground, using the ovipositor, makes holes in it and starts laying eggs. The locust secretes a special foamy sticky substance, the solid is the development of eggs, this period is usually about 12 days, there are usually 50-70 eggs in the egg.

The born larva has to work hard to get out of the earth into the light. To become an adult insect, the larva has to undergo 5 molts..

Having a constant, they can breed year-round. During her life, the female makes from 6 to 12 clutches of eggs..

Caring for offspring: the locust cannot be called a caring mother, because, unlike other insects (bees, wasps), which tend to place a supply of food in each cell (mink) where the egg they have laid is located, so that the hatched larva has something to eat, it leaves their future offspring to their fate.

All stages of reproduction in pictures:

Mating process

laying eggs

Last molt

Forms of development

The uniqueness of this insect lies in the fact that it has 2 forms of development:

• single(filly) - a form of development with a sufficient amount of food;
• gregarious. When food is scarce, fillies unite in flocks and fly in search of food. At the same time, their appearance changes, the size of the body and wings becomes larger, this happens through the friction of individuals against each other with the limbs, on which a special organ is located.

Mares turn into locusts, a real disaster for people, whose huge hordes in a matter of days can gobble up the entire crop in the fields, gardens and orchards. Along the way, the females lay eggs, of which next year it is no longer fillies that hatch, but locusts.

Locusts in the distant past were the enemy of humanity No. 1, but modern people have heard little about it. Meanwhile, it is described in the ancient Egyptian papyri, the Bible, the Koran, the works of the Middle Ages, artistic literature XIX century. It's time to learn more about the insect, whose name in the past centuries served as the personification of a humanitarian catastrophe.

Migratory locust (Locusta migratoria).

The first thing to be said is that the locust is not one species, but a whole superfamily in the Orthoptera order, uniting relatively large jumping insects. Their closest relatives are fillies (they, unlike locusts, never form mass concentrations), a little more distant are real grasshoppers and crickets.

The appearance of the locust is also typically “grasshopper”: an elongated body with long legs bent “at the knees”, a relatively large head with large eyes, a pair of rigid elytra and a pair of transparent wings, completely invisible when folded, but opening like a dragonfly when flying. On top of that, the locust has an excellent ear for music (its auditory openings are located on the abdomen) and special devices for making sounds. The latter include notches on the femora and thickened veins on the elytra. When the locust runs its thigh along the elytron, a loud chirring of various tonalities is heard.

If the locust looks like a grasshopper and chirps like a grasshopper, then how is it different from it? And the main and most reliable sign that allows you to accurately distinguish a locust from a grasshopper is the length of the antennae: in grasshoppers they are often equal to the length of the body, while in locusts, on the contrary, the antennae never exceed half of its length.

In some species of locust, the crown of the head is elongated and, together with the antennae, forms a narrow cone, while the contours of the body merge with the oblong leaves of cereals, on which this insect usually feeds.

Sexual dimorphism in these insects manifests itself differently even within the same species: in the solitary phase, males and females differ in the color of their integument, while in the gregarious phase these differences are not expressed. In general, the coloring different types locusts can be very dissimilar - bright green, yellow, brown of various shades, gray and even blue-red. But whatever the color of individuals, it is always more or less similar to the color of plants or soil on which this species is found. Thus, the color of the locust is camouflage. It is also noteworthy that the color of a single form of locust is not determined by genes, as is the case in most other animals, but by the environment. In other words, what kind of environment a locust larva sees around itself, it will grow in such a color. Even in the offspring of the same pair, individuals of dissimilar colors can be obtained if they are grown on different substrates.

The excellent disguise of the Italian Locust (Calliptamus italicus) does not work only during the flight, when bright pink spots at the base of the wings become visible.

The maturation of the locust takes place at a record speed, already 4-10 days after the last molt, the insects mate. The female then dips her long ovipositor into the ground and lays between 300 and 1200 eggs. At the same time, a whitish liquid is released from the ovipositor, which quickly solidifies. This kind of "mounting foam" securely seals the egg capsule. If the masonry is made in the area with cold winter, then during frosts, the development of eggs stops and wintering occurs in this state, and the larvae appear in the spring. In warm regions, development proceeds without delay and lasts about 14-16 days. The hatched larvae look like worms, which is an adaptation to living in the soil. However, this nursery period of their life lasts a matter of hours. The larvae, wriggling, crawl up and, as soon as they reach the surface, they immediately molt. The second instar larvae (nymphs) look like adults, but they are still wingless and have a slightly shortened body and antennae. With subsequent molts, they acquire the rudiments of wings, increase and lengthen, reaching “adulthood” in just 40 days. Adults (adults) die after laying eggs.

A section of soil with a locust egg: oblong eggs are visible below, and above - a passage sealed by the foamy secretions of the female.

The total range of all locust species is quite wide and covers the zone of dry tropics, subtropics, as well as the warmest regions of the middle zone. You can meet these insects on all continents except Antarctica and North America. However, on the last continent, the absence of native species is more than compensated for by the harm caused by migratory locusts brought from the Old World. As for Eurasia, here the northern border of the locust distribution runs through the Central Russian Upland and Western Siberia, however, in these areas, outbreaks of numbers are extremely rare and never take on catastrophic proportions.

For the first time in their lives, molted locust nymphs emerge from a nest hidden in the ground.

Without exception, all locust species are inhabitants of open spaces, which is explained by their diet. The fact is that these insects prefer to eat cereals, which are mostly photophilous. However, the habitats of different species can vary significantly. On this basis, locust species are usually divided into two groups. Some species clearly gravitate to areas covered with a dense and uniform grassy cover, therefore they live in meadows, steppes, savannahs and reed beds along the banks of reservoirs. Others prefer areas with a bare surface, dotted with rare shrubs and tufts of grass, so they are found in deserts and semi-deserts, foothills and rock outcrops.

The amazing thing is that, by nature, locusts are… harmless. Under normal conditions, these insects lead a solitary lifestyle and cause no more damage to vegetation than grasshoppers, which are lovely to everyone. But unlike the latter, a radical restructuring of instincts, biochemical processes and physiology can occur in locusts. Hunger is the trigger for change. If grasshoppers live mainly in moderately humid and rich in vegetation areas, then locusts, attached to dry biotopes, often face seasonal food shortages or cyclical droughts, which are not uncommon in steppes and semi-deserts. When the food base is critically depleted, insects willy-nilly are forced to concentrate on areas where at least some grass has survived. This is where the fun begins!

Many nymphs sitting side by side touch each other with their feet, from frequent contact their nerve cells are excited and begin to secrete hormones. Under their influence, the larvae change color, but not to camouflage, but to a special one - the same for everyone! For example, in migratory locusts, the migratory form is black and yellow, although solitary adults are more often green. Such colors are similar to uniforms that unmistakably allow soldiers to distinguish their own from others on the battlefield. Due to the inclusions of dark color, the bodies of the nymphs are heated by the sun more than usual, their temperature rises, breathing quickens, they become more mobile. In larvae younger age at the same time, crowding instincts are intensified, they form even denser clusters - swarms. Older larvae begin to move in one direction, but since their wings are underdeveloped, this movement still looks like a hike. However, locust clusters even at this stage look quite menacing and unpleasant, because in some places insects can form a layer up to 10 cm thick. Over the entire period of the campaign, they are able to move up to 30 km, even rivers are not able to stop the marching swarm, because nymphs that cannot fly are excellent swimmers. The last molt does its job: the larvae acquire wings and turn into adult migratory individuals. AT certain moment the whole flock rises into the air - the flying armada is ready for the invasion!

Nymphs of the Schistocerca, or Desert Locust (Schistocerca gregaria) march through the Negev desert (Israel).

Usually a swarm of locusts flies at a speed of 10-15 km/h at an altitude of up to 600 m, although individual swarms were recorded at altitudes from 2 to 6 km. The most favorable for flight is calm or light wind; with strong gusts, the locust sits on the ground and waits for unfavorable weather. Insects prefer to fly during daylight hours with short stops for feeding, but sometimes the flight can continue at night. During the day, a flying flock is able to overcome 80-120 km, and for the entire period of migration it moves hundreds and thousands of kilometers. Historically, the centers of mass reproduction are North and Central Africa, the Arabian Peninsula, Iran, Pakistan, northern India, and Afghanistan. From these arid regions, swarms of locusts fly to where there is more moisture and food: from North-West Africa - to The Iberian Peninsula(in some cases they even flew to England), from Central Africa- to Egypt, from the Arabian Peninsula - to the Middle East, from Central Asia - to Kazakhstan, Turkmenistan, to the south of Russia.

A flock of locusts flies over the Astrakhan region.

In the description of locust raids, all literary sources are extremely unanimous. A raid always starts suddenly and looks to the observer like a black cloud on the horizon approaching with an ominous rustle. As the “cloud” approaches, it becomes clear that it is heterogeneous, and now hordes of insects fill the entire space around. The locust flies so tightly that it is impossible to dodge it: insects get into the face and mouth, crawl up the arms, fall to the ground, crunch underfoot, and the surviving individuals take off again. In a matter of minutes, they outshine the sun, cover the ground, buildings, trees, pets, vehicles with a continuous layer, penetrate into all cracks, clog houses.

flock small size, as in this photo, has between 40 and 50 million individuals.

Each individual tries to bite off what it sits on. It should be especially noted here that adult migrating locusts are distinguished by their amazing omnivorous nature, which is not characteristic of nymphs and solitary adults. Therefore, the swooping locust devours all the vegetation that it sees. First of all, bread, melons and industrial crops suffer from it - these delicacies go to the vanguard of the flock. But since the raid can last from several hours to a couple of days, those who arrive later pounce on everything that the pioneers did not eat: fruit trees, weeds, products and textiles of plant origin. During this feast, noise from the movement of many jaws is heard everywhere. Each insect absorbs about 300 g of food in its life - it seems to be a little, but if you consider that swarms of locusts number in the millions and billions of individuals, then the scale of losses in agriculture is simply colossal. When the flock flies away, the place of the feast turns into a lifeless land, on which, like sad monuments to human grief, the bare remains of trees stick out.

Due to their fecundity and precocity, locusts often become the object of laboratory research.

It is noteworthy that one of the oldest descriptions of the locust is given in the Bible, where it is succinctly referred to as one of the "ten plagues of Egypt." Its invasions often led to an acute shortage of food and feed and, as a result, to starvation, loss of livestock, weakening of the military and economic power of entire states. On top of that, locust swarms were associated with the spread of "pestilence", including plague. Scientists deny such a connection, because the locust is not a carrier of plague bacilli, but the clue can be found in the messages of the XVII-XIX centuries. The chroniclers of these centuries were more talkative than biblical writers and left us a description of a curious detail - bad smell that accompanied the locust raids. The source of the smell was not living insects, but the corpses of those crushed and died of natural death after laying eggs. Since one swarm of locusts could number billions of individuals, such an accumulation of decaying biomass attracted flies and rats, which were precisely the carriers of infections.

One of the largest locust raids on the Mauritanian capital of Nouakchott in 2012 was associated with the overthrow of Gaddafi in neighboring Libya - in the country covered by the revolution, they stopped paying attention to the fight against this pest.

It is not surprising that people perceived the locust invasions as the highest punishment sent by God. In ancient times, they were completely unable to withstand such a disaster, and since the Middle Ages, attempts have been made to contain the offensive: they tried to scare away the locusts with smoke and sulfur, kindled fire barriers on the way of foot kuligs, crushed livestock with their feet and hooves, beat everything that came to hand. In the 20th century, vacuum cleaners and flamethrowers were added to these methods. But the abundance of locusts overcame everything.

In some species of locust, the wings are completely covered with patterns in such a way that they resemble the wings of a butterfly.

A very indicative example is Ukraine, where in past centuries locusts were a common insect in the south of the country. It bred in the reed beds in the Dnieper delta, from where it made devastating raids on the agricultural central regions, at times reaching Poland and Lithuania. After the plowing of the virgin steppes and the introduction of crop rotation, many eggs began to die during the cultivation of the land, and now locusts are rare here.

Reed beds in deltas major rivers- natural reservoirs where locust hatching takes place. This photo shows the formation of a flock.

An even more impressive example is the Rocky Mountain locust ( Melanoplus spretus). It is the only native locust species in North America that breeds in the foothills of the Rocky Mountains, from where it raided the lowlands of Colorado, Nebraska, Kansas, Missouri and Minnesota. American farmers could not overcome these hordes until the foothills were plowed up, as a result of which these locusts ... died out!

However, this is the only species of locust that has suffered such a fate - all the rest are quite prosperous and numerous. Outside of agricultural areas, these insects play a significant role in ecosystems, as they serve as food for many species of birds and animals: guinea fowl, partridges, small falcons, kites, secretary birds, ravens, crows, bustards, meerkats, wild pigs, warthogs. Often, cases of eating locusts by herbivorous ungulates were noted, but researchers differ in their assessment of this phenomenon. Some say that wild antelope and livestock willingly take advantage of such occasional feeding, others testify that after eating locusts, livestock died.

The rocky phymateus (Phymateus saxosus), native to Madagascar, is poisonous due to the toxic sap of the milkweeds it feeds on.

By the way, the Bible reveals to us another curious fact: the Gospel of Matthew mentions that John the Baptist, living in the desert as a hermit, ate locusts and wild honey. Few people guess what kind of locusts they are? And this is nothing but a locust. The abundance of these insects in the Middle East has long encouraged people to find them at least some useful application, therefore, the ancient Jews and Arabs often ate locusts, especially during their raids. It no longer occupies such a prominent place in modern Middle Eastern cuisine, but is a common product in China and Thailand.

Locust tissues contain practically no fat, but are rich in protein and minerals, which puts it in a number of dietary products. The high calorie content also adds to its culinary value. The methods of preparing these insects have not changed over the centuries. Most often, the caught locusts are boiled until softened, and then fried in oil with salt and spices, but if they want to prepare for future use, then after boiling the insects are dried, sprinkled with salt. Locusts cooked this way become crispy and taste like a cross between chicken and potato chips (or roasted chestnuts).

They sell it by weight or strung on sticks; before use, it is customary to tear off hard paws, wings and head from locusts.

Class - real insects

Contract - Orthoptera

Family - Acrididae

Basic data:

DIMENSIONS

Length: 1.5-20 cm.

Shape and color: depend on the type. Some have brightly colored wings.

Mouth apparatus: gnawing.

Wings: some species do not have them, others have 2 pairs of wings.

BREEDING

Mating period: in the tropics all year round; in areas with a cold climate - in the summer.

Number of testicles: 3-100.

Incubation period: depends on temperature and precipitation. Sometimes up to several months.

LIFE STYLE

What does it eat: mainly leaves, grass and other plants.

Sound: the sound is created as a result of friction of the thigh of the hind leg against the veins on the elytra.

RELATED SPECIES

Many species of real grasshoppers and crickets.

More than ten thousand species of locust are found all over the world. These voracious insects are considered the largest plant pests. From their closest relatives, real grasshoppers and crickets, they differ in short antennae that do not exceed half the length of the body.

WHAT DOES IT FEED

Locusts usually live on the leaves and flowers of green plants. They gnaw leaves with strong upper mandibles, and grind them with smaller and weaker lower mandibles.

Since the mandibles of the locust move from side to side, the insects usually sit in the center of the leaf, on its longitudinal axis, and gnaw the leaf from edge to edge. Only a few true locust species feed exclusively on grass. Leaves are the food for most locust species. perennials, shrubs and trees. Some locust species can even feed poisonous plants which other insects and animals do not eat.

Concentrating in their body, the poison provides insects with protection from enemies, since they themselves become poisonous. Such locusts have a bright color that warns of their inedibility.

SELF DEFENSE

Many locust species found in the humid tropics have warning coloration. Bright or contrasting colors in which their body or wings are painted warn that the insect is poisonous. In the body of such locusts there is a poison that accumulates from the plants that they feed on. If you touch such an insect, then it emits an unpleasant taste and smell of foam.

Other locust species that do not have „ chemical weapons", usually come in camouflage colors. The color of insects varies depending on the habitat, so the color of many of them is like leaves, blades of grass or pebbles. Some Central European species of locust are able to almost completely merge with the background that surrounds them, and it is almost impossible to notice them If frightened, such an insect immediately flies away, and before landing and becoming "invisible" again, it opens bright blue or red wings that scare away the enemy.

LIFESTYLE

Locusts inhabit all those regions where there is at least a small amount of plants. Only an ignorant person can argue that these insects live most often in meadows and fields. Most beautiful views Locusts are found in humid tropical jungles. They live even in the mountains at an altitude of up to 6,000 m above sea level. And although locusts prefer green plants, there are species that inhabit semi-deserts and even deserts. Locusts are very gluttonous, damaging crops. Many species - those that live in mountainous areas - do not have wings and therefore move by jumping. Only 60 out of 10,000 true locust species are found in Central Europe.

BREEDING

Locust mating can last up to several hours. Almost immediately after mating, the female lays eggs, usually by burying them in the ground. The female ovipositor is very elastic and can almost double in length. This allows her to lay eggs deep enough in the ground. Each portion of eggs is enveloped in a special foamy liquid, which, when solidified, forms a kind of capsule. The time required for the development of embryos depends on temperature and climate. Embryonic development begins immediately after the female has laid her eggs. In species living in regions with a cold climate, the development of embryos lasts longer, before the onset of cold weather. Then it stops and resumes only in the spring, when warming comes. In warm countries, after a short time, worm-like larvae hatch. After the first molt, they become similar to adults, they just do not have formed wings. After that, the larva molts another 4-5 times. Each time, its size increases, and at the same time, antennae and rudiments of wings gradually lengthen.

DEVICE FEATURES

All species of locusts emit a characteristic "chirring". This peculiar "singing" of insects in many people brings to mind the image of a flowering meadow on a hot summer day. The locust sound apparatus is located on the hips hind legs and elytra. Along inner surface the femora are tubercles, and one of the veins of the elytron is thicker than the others. Locusts make sounds by rapidly moving the thigh, while the tubercles touch the vein. Because the tubercles are uneven, the result is a staccato chirping sound. In most locust species, both males and females chirp.

• There are many tropical locust species that do not chirp.
• Some locust species cover a distance of 200 times their body length in one jump.
• The bodies of true locusts can have a wide variety of colors and color variations. In addition, there are striped, spotted and speckled insects.
• Locusts living in Europe chirp certain types so different that females "recognize" the male of their species by its "voice".
• One of the largest locust species is Tropidacris cristatus, native to Costa Rica. One ornithologist took this locust for an outlandish bird and caught it for the exposition of the zoological museum.

CHARACTERISTIC FEATURES OF LOCUST

A characteristic feature of the locust is the peculiar structure of the hind legs. They allow insects to jump a long distance. Like grasshoppers and crickets, locusts are excellent musicians.

WHERE Dwells

Locusts are numerous throughout the world, more often living in areas with rich vegetation. They are also found in semi-deserts.

PROTECTION AND PRESERVATION

True locusts are only threatened with extinction where their habitats are destroyed, especially in tropical rainforest areas. Some species are considered malicious pests.

Hordes of locusts hit the southern regions of Russia. Video (00:02:52)

In the south of Russia, all forces are thrown into the fight against locusts. There are more and more fastidious insects; crops in several regions are already suffering from them. So, for example, in the Stavropol Territory, the current migration of giant grasshoppers is the largest in several years.

The population is so large that it is impossible even to walk along the road without stepping on an insect. Now these locusts are about three weeks old, they are able to overcome up to 15 kilometers per day. And in a few days they will grow wings and this distance will increase to 50 kilometers.

In the eastern part of the region, where the Stavropol Territory borders on the steppes of Dagestan and Kalmykia, most of the land of the Levokomsky district is set aside for pastures. Therefore, these fields are never plowed. Locusts, which lay their larvae in the ground, multiply very actively and begin to move to where there is more food - to the west.

HORROR! LOCUST ATTACK IN STAVROPOL. IT HAS NOT HAPPENED FOR 30 YEARS / Life life TV. Video (00:03:10)

An invasion that every day takes on the proportions of a catastrophe! The Stavropol Territory is attacked by hordes of locusts. The fight goes on both on the ground and from the air, but chemicals cannot resist the giant flocks of pests that devour hectares of crops on their way. There has not been such insect migration in the region for the last 30 years.
There are so many locusts that it ripples in the eyes! Insects overcome the Stavropol Territory for several days. And if the city people, joking with them, fight with slippers, then in the village there is at least crying from pests.

DANGEROUS LOCUST. GIANT LOCUST EATING. Video (00:02:10)

DANGEROUS LOCUST. GIANT LOCUST EATING. Locust invasion. Giant locust. The locust eats the crop. Locusts are arthropods, class - insects, family locust. Locusts usually live on roadsides. The giant locust is a larger variety of grasshoppers. Dangerous Locusts gather in huge flocks, destroying all plants, This is the hunger games. Locusts are dangerous. There are swarms of locusts up to 40 billion individuals. The locust's favorite food is cereals. Due to the lack of food, the locust eats all vegetation. Enemies of locusts, grasshoppers - starlings, storks, larks. In some countries, locusts are eaten, cooked in oil, locusts are a delicacy. Locusts gather in flocks - migratory locusts.

Grasshopper or locust. Video (00:03:00)

Grasshopper or locust? How to distinguish a grasshopper from a locust? Do grasshoppers harm our garden? Learn more about it in our video

Sochi is attacked by hordes of Moroccan locusts - 06/26/16. Video (00:02:28)

Anomalous locust invasion in Sochi. This time a winged Moroccan insect hit the resort

Sochi, Russia, Locust Invasion, Locust, Sochi, Krasnodar region, Locust control

Locust or spider? An unknown insect shocked Chelyabinsk residents. VIDEO. Video (00:00:36)

Locusts - friend or foe?

One of the cute signs of a roast summer day- the deafening crackling of locusts and the melodious roulades of grasshoppers... But when the abundance of insects increases by orders of magnitude, these sounds indicate a catastrophe, ecological and economic. No wonder the locust has already gained fame as one of the “plagues of Egypt”: “And the locust attacked all the land of Egypt, and lay down all over the land of Egypt in great numbers; before there was no such locust, and after this there will be no such.”

For decades, scientists from different countries trying to unravel the mysteries of these insects known from biblical times. Why, for example, some locust species remain rare, while the number of others can increase significantly? Why do individuals of some species at the peak of their numbers dramatically change their appearance? Until now, there are no answers to all questions, but it was possible to find out that eating crops by these pests turns out to be a boon for natural grassy communities, since it contributes to the destruction and rapid return of plant mass to the cycle of matter and energy.

"And the locusts and caterpillars came without number."
Psalter, Psalm 104

Steppe. Hot summer day. The deafening crackling of locusts and roulades of grasshoppers... It is at such a time that you realize how many of these "singing in the grass" are so sweet to hear. But when the abundance of some of them increases by orders of magnitude, this is already a catastrophe, ecological and economic.

For many decades, scientists from different countries have been trying to unravel the mysteries of these insects known since biblical times. Why, for example, some locust species remain rare, while the number of others can increase significantly? Why do some of them form huge flocks from time to time? Until now, far from all such questions have answers ...

Locusts (Acridoidea) are rather large insects belonging to the order of Orthoptera (Orthoptera). Their closest relatives are well-known grasshoppers and crickets, as well as little-known small inhabitants of the plant litter, jumpers and quails.

Many of the Orthoptera are highly visible in their natural habitats: they are brightly colored, "musical", jump high and are capable of flight.

These insects have long attracted human attention: in the East it is customary to keep crickets and grasshoppers at home instead of the songbirds we are used to, and fights between male crickets have been an exciting sporting spectacle for centuries. In a number of countries in Asia and Africa, local locust species are still considered a delicacy: they are fried, boiled, dried.

But still, we remember them much more often when we learn about the damage caused by the next invasion of voracious insects. It is not surprising that in the human mind, locusts are primarily associated with the "image of the enemy."

And the locust attacked all the land of Egypt...

The development of agriculture over the past ten thousand years is inextricably linked with the regular incursions of locusts into cultivated fields. Images of one of the most famous pest species - the desert locust - are found in the tombs of the first Egyptian pharaohs. Assyro-Babylonian cuneiform tablets testify to the damage caused by the desert locust.

The locust is mentioned dozens of times in the Bible, mostly as a creature hostile to humans. No wonder she earned the glory of one of the apocalyptic “Egyptian plagues”: “And the locust attacked all the land of Egypt, and lay down all over the land of Egypt in great numbers; before there was no such locust, and after this there will be no such” (Exodus, 10, 14).

The inhabitants of Ancient Russia also faced the mass reproduction of this pest. So, in the "Tale of Bygone Years" is described scary picture, observed at the end of the 11th century: “The locust came on August 28 and covered the ground, and it was scary to look, it went to northern countries devouring grass and millet."

Since then, little has changed. So, during the invasion of locusts in 1986-1989. In North Africa and the Middle East, almost 17 million hectares of agricultural land were treated with chemical insecticides, and the total cost of the outbreak itself and its consequences exceeded $270 million. In 2000, more than 10 million hectares were cultivated in the CIS countries (mainly in Kazakhstan and southern Russia).

Outbreaks of mass reproduction are primarily characteristic of the so-called gregarious locusts(in everyday life - just locusts). AT favorable conditions they form kuligi– huge concentrations of larvae, the density in which can exceed 1000 ind./m 2 . Kuligi, and then flocks of adults, can actively migrate, sometimes by very long distances(There are known cases of flights of a flock of locusts across the Atlantic Ocean).

Fortunately, only a few species are capable of reaching catastrophic numbers. First, it is the desert and migratory locust. These most famous and widespread representatives of gregarious locusts have another feature - a pronounced phase variability. This means that individuals at different population phases differ markedly from each other in appearance. Individuals of the gregarious phase are characterized by dark coloration, longer wings and better muscle development.

Changes in the appearance and abundance of other species of gregarious locusts (for example, the Italian and Moroccan locusts living within the CIS) are not so striking, which, however, does not prevent their flocks from flying over considerable distances (tens and even hundreds of kilometers) in search of food.

Fertility Creators

It is the gregarious species of locusts that cause the main damage during the years of outbreaks of their numbers, destroying almost all green parts of plants in their path. But their non-herd relatives (who are often called filly and skates), as well as their distant relatives from the Orthoptera order, can also breed in in large numbers and destroy vegetation cover natural ecosystems, as well as in the fields.

But should these insects be considered only the punishment of mankind? In fact, as herbivorous animals, they are essential element food webs in grassy ecosystems, primarily in the steppes, prairies, semi-deserts and savannahs. This role, not so obvious, was noted in the biblical texts: “The locusts ate the locust leftover, the worms ate the worms leftover, and the beetles ate the worms leftover” (Book of the Prophet Joel, 1, 4).

The well-known Siberian entomologist I.V. Stebaev in the early 1960s. showed that in the temperate latitudes of Eurasia, locusts during the warm season can consume more than 10% of the green grass phytomass. In addition, they actively use litter for food, and with a lack of plant food, they are able to switch to the corpses of their fellows, excrement of other animals, etc. (locusts can even eat textiles and leather products!). One average individual of the Siberian steppe locust consumes about 3–3.5 g of green parts of plants in its entire life, which is about 20 times its adult weight (Rubtsov, 1932). Somewhat higher numbers are obtained for North American and South African locusts.

Such gluttony of these insects paradoxically turns out to be a boon for natural communities. Thus, Stebaev and his colleagues found that locusts contribute to the destruction and rapid return of plant mass to the cycle of matter and energy: in the intestines of many steppe species of locusts, leaves and stems of grasses are not so much digested as crushed and fragmented, and symbiotic intestinal microorganisms enrich these fragments. vitamins of group B. As a result, locust excrement is converted into an excellent organic fertilizer. In addition, Canadian researchers have shown that locusts, by eating leaves, activate plant growth and increase their productivity.

Thus, despite the fact that the damage caused by locusts and other orthopterans can be enormous, their role in ensuring the normal functioning and sustainability of natural ecosystems, especially grassy ones, is colossal.

Is the person an enemy or a friend?

People have been trying to fight locusts for centuries. Until the beginning of the 20th century. used enough simple ways: mechanical destruction, burning and plowing of oviposition deposits.

Later, various chemicals began to be widely used, and over the past decades, the spectrum of insecticides has changed significantly: the infamous DDT and HCH were first replaced by organophosphorus compounds, and then by more specific synthetic pyrethroids, inhibitors of the synthesis of chitin (the main component of the external skeleton of insects), etc. .

However, despite the decrease in the overall toxicity and effective doses of new insecticides, the environmental problems of their use have not disappeared (primarily this applies to the death of other invertebrates). Biological preparations, biologically active substances and other similar means are deprived of these shortcomings, in many cases giving a good effect. However, the effect of such drugs does not appear immediately, and it is impossible to quickly suppress the outbreak of the pest with their help.

As a result, despite all the long and titanic efforts, including the massive use of DDT and large-scale plowing since the development of virgin lands, it has not yet been possible to solve the "locust" problem. However, in some cases, human impact on locusts and other orthoptera can have devastating consequences, and this applies not only to rare species with small ranges. Thus, according to the American researcher D. Lockwood, the victim of changes in land use practices in late XIX in. became the famous Rocky Mountain locust mentioned above. After another outbreak of mass reproduction, its populations remained in the river valleys, which began to be actively plowed up. As a result, today this species is considered completely extinct: its last representative was caught in 1903.

But there are also reverse examples: in a number of cases, human activity contributes not to a decrease, but to an increase in the number of orthoptera. Such a result is caused, for example, by overgrazing of livestock, the introduction of anti-erosion farming systems and an increase in the area of ​​fallows. So, in recent decades, in the southeast of Western Siberia, due to the use of anthropogenic landscapes, the ranges of the small cross, blue-winged filly, common lamina wing, etc. have been expanding.

There are also known cases of anthropogenic dispersal of Orthoptera over long distances. It is in this way that several European species, such as the large ambush predator the prairie bony, have colonized some of the warm-temperate regions of eastern North America.

singing in the grass

Locusts and their relatives from the order Orthoptera are in themselves an interesting object for research. So, few people know that among them there are species that spend their entire or almost their entire lives on trees and shrubs (there are especially many such forms in tropical forests). Some inhabitants of warm latitudes are able to move on the surface of the water like water striders, others swim quite well, even under water. A number of orthoptera (for example, bears) dig holes, and pseudo-grasshoppers can settle in caves.

It is believed that locusts are polyphagous, but in reality almost all of them prefer to feed on quite certain groups of plants, and some of them even have a pronounced trophic specialization. Such gourmets can eat, for example, poisonous plants (wrestlers, hellebore, etc.) without harming their health. Grasshoppers, especially large ones, are dominated by predators or species with a mixed diet, while a significant part of the remaining orthoptera is able to process dead plant litter.

The adaptations of insects associated with reproduction are very interesting and diverse. This is especially true for the means of communication by which the sex of an individual can be recognized. Orthopteran males are unique in the variety of ways of making sounds: here is the interaction of the right and left elytra; hind limbs and upper side of elytra; hind limbs and underside of elytra; back thighs; a special Krauss organ; finally, just “gnashing” of the jaws. Sometimes females can also sing.

Species that are not able to make sounds often use signal coloration: males have very brightly colored hind wings, hind legs, inner side hind femora, which insects exhibit during courtship.

In most acridoids, after fertilization, the females lay a group of eggs in the soil, surrounded by a more or less strong shell. Such a masonry, by association with a traditional clay vessel, is called a egg-pod. Other orthoptera also lay their eggs directly into the soil, but there are grasshoppers that use green plants for this. They file leaves or shoots with the edge of their ovipositor and lay their eggs in the resulting gap.

The well-developed locomotion ability of locusts and their relatives also deserves special mention. Many of them are able to actively walk, jump and fly, however, as a rule, their movements do not exceed tens of meters. Ratchets common in the south of Siberia can stay in the air for tens of minutes: using flows warm air, they rise to a height of over 10 m. But even these champions most often return to the site from which they took off (Kazakova, Sergeev, 1987). Exceptions are gregarious locusts. As already mentioned, they can move over much longer distances: larvae - up to tens and hundreds of meters, and adults fly away for tens and hundreds of kilometers.

Some non-flying species use non-trivial methods for settling. Thus, the English researcher G. Hewitt and his colleagues (Hewitt et al., 1990) observed in the Alps how individuals of the flightless filly jumped on sheep and literally moved on horseback.

Two centuries at gunpoint

Locusts and their relatives have been actively studied over the past two centuries: the Orthoptera order was identified by P. A. Latrey as early as 1793. Researchers of the 19th century. they were mainly engaged in describing new forms and studying the individual development of these insects, but even then the first ecological observations appeared, including those of potentially harmful species.

In the XX century. these traditional lines have evolved: numerous new taxa have been identified, predominantly from tropical regions; the main patterns of distribution of Orthoptera have been established. But special attention was paid to ecology - intrapopulation interactions, dynamics of populations and communities, and the role in natural and anthropogenic landscapes.

An outstanding role in the study of locusts was played by our compatriots who worked both in the former USSR and abroad. So, a member of the English Royal Society and the founder of the famous Anti-Locust Center in London B.P. Uvarov in the 1920s. developed the theory of phases, which became the basis of modern locust ecology.

Of course, at the end of the XX-beginning of the XXI centuries. researchers have the opportunity to obtain fundamentally new data on these insects using molecular genetic, biochemical and information methods. This is especially true of the mechanisms of transition from a solitary phase to a gregarious one and vice versa, migrations of bands and flocks, etc.

However, these opportunities are often not realized. This is largely due to the fact that interest in these insects (as well as research funding) drops sharply after the suppression of the next outbreak, when the danger to agriculture has passed.

Nevertheless, the data that have been obtained over the past years allow us to look at the locust problem from a fundamentally different point of view. Thus, it is traditionally believed that within the same natural region, the spatio-temporal dynamics of settlements of the same type is practically the same.

However, studies of the Italian locust populations in the Kulunda steppe in 1999-2009 revealed a complex "wavy" pattern of long-term spatial redistribution of maximum and minimum insect densities. In other words, even neighboring groups of local settlements of this locust species at different times emerged from the population depression and reached the peak of reproduction.

What determines such a different character of population trajectories? It turned out that one of the main factors determining the organization of populations of massive (and often potentially harmful) locusts is the heterogeneity of the natural environment. After all, each habitat is not similar to another, moreover, on each of them such important indicators for insects as moisture content, characteristics of soils and vegetation cover, and the degree of anthropogenic impact are constantly changing.

Another disturbing result is the coincidence of many areas of locust outbreaks with centers of diversity for other insects. And pest control can eventually lead to the death of rare species.

The information that scientists have today indicates that today people underestimate the problem of locusts and their relatives.

It is necessary to continue long-term studies of the ecology and biogeography of mass species populations, as well as multi-species communities. Such data can serve as a foundation for monitoring, as well as the development of population management measures aimed at minimizing environmental damage and maintaining biodiversity. The very system of managing the populations of these insects should be aimed not at suppressing mass reproduction, but at preventing them.

There is a need to develop relevant applications information technologies, primarily geographic information systems and Earth remote sensing systems. It is in this direction that a technological breakthrough is possible, which will ensure that forecasts reach a fundamentally different level. And this is especially important now, in the context of an increase in the frequency of climatic perturbations and the intensification of human activity that transforms the environment.

Literature

Lachininsky A. V., Sergeev M. G., Childebaev M. K. et al. Locusts of Kazakhstan, Central Asia and adjacent territories // International Association of Applied Acridology, University of Wyoming. Laramie, 2002. 387 p.

Sergeev M. G. Orthoptera insects (Orthoptera) of North Asia: fifty years later // Eurasian Entomological Journal. 2007. V. 6, No. 2. P. 129–141 + insert II.

Lockwood J. A. Locust. New York: Basic Books, 2004. 294 p.

Lockwood J. A., Latchininsky A. V., Sergeev M. G. (Eds.) Grasshoppers and grassland health: Managing grasshopper outbreaks without risking environmental disaster. Kluwer Academic Publishers, 2000. 221 p.

Samways M. J., Sergeev M. G. Orthoptera and landscape change // The bionomics of grasshoppers, katydids and their kin. CAB International, 1997. pp. 147–162.

Sergeev M. G. Conservation of orthopteran biological diversity relative to landscape change in temperate Eurasia // Journ. insect conservation. 1998 Vol. 2, N 3/4. P. 247–252.

locust- this is a large arthropod insect from the family of true locusts (lat. Acrididae), included in the order Orthoptera, suborder short-whiskered. In ancient times, it was the main threat to crops of cultivated plants. The description of the locust is found in the Bible, the writings of ancient Egyptian authors, the Koran and treatises of the Middle Ages.

Locust is a description of an insect.

The locust has an elongated body from 5 to 20 cm long with hind legs bent at the “knees”, much larger than the middle and front legs. Two rigid elytra cover a pair of translucent wings, which are difficult to see when folded. Sometimes they are covered with various patterns. Locusts have shorter antennae than crickets or grasshoppers. The head is large, with large eyes. The sound of the locust is formed as follows: the males have special notches located on the surface of the thighs, and special thickenings on the elytra. When rubbing them against each other, a specific chirring is heard, which has a different tone.

Locust color does not depend on genes, but on environment. Even individuals from the same offspring, grown in different conditions, will differ in color. In addition, the color of the protective covers of an insect depends on the phase of its development. For example, in a single stage of life, a male or female locust may have a bright green, yellow, gray or brown camouflage coloration and pronounced sex differences. Upon transition to the gregarious phase, the coloration becomes the same for all, and sexual dimorphism is leveled. Locusts fly very fast: when flying, a swarm of locusts can cover a distance of up to 120 km in one day.

What is the difference between a locust and a grasshopper?

• The locust is an insect from the locust family, the suborder of the short-whiskers, and the grasshoppers are part of the grasshopper family, the suborder of the long-whiskers.
• The whiskers and legs of the locust are shorter than those of the grasshopper.
• Grasshoppers are predators, and locusts are herbivores. Although sometimes during long flights locusts can eat a weakened individual of the same species.
• Locusts are active during the day, while grasshoppers are active at night.
• The locust is hurting agriculture human, as opposed to harmless grasshoppers.
• Locusts lay their eggs in the soil or leaves on the ground, and in the stems of plants or under the bark of trees.

Locust species, names and photos.

(lat. Dociostaurus maroccanus)- an insect of small size, the body length rarely exceeds 2 cm. The color of adults is reddish-brown, with small dark spots scattered along the body and an unusual cross-shaped pattern light tone on the back. The hindquarters are pink or yellow on the thighs and red on the lower legs. Despite their miniature size, the Moroccan locust causes great damage to farmland and cultivated crops, gathering in numerous hordes and destroying absolutely everything that grows on the ground in its path. This species of locust lives in Africa, in Central Asia and Algeria, in sultry Egypt, in arid Libya and in Morocco. It is found in European countries, for example, in France, Portugal, Spain, Italy and even the Balkans.

(lat. Locusta migratoria)- a rather large insect: the body length of mature males is from 3.5 to 5 cm, in females it ranges from 4-6 cm. The color of the Asian locust varies in several colors: there are individuals of bright green, brownish, yellow-green or gray . The wings are almost colorless, except for a slightly pronounced smoky shade and the thinnest streaks of black. The hind thighs are dark brown or blue-black, the lower legs may be beige, reddish or yellow. The habitat of this species of locust covers the entire territory of Europe, Asia Minor and Central Asia, the countries of North Africa, the regions of North China and Korea. Also, the Asian locust lives in the south of Russia, is found in the Caucasus, in the highlands of Kazakhstan, in the south of Western Siberia.

(lat.Schistocerca gregaria) - an insect with a fairly large size - females reach a value of 8 cm, males are slightly smaller - 6 cm in length. The coloration of the Desert Locust is dirty yellow, the wings are brown, with many veins. The hind limbs are bright yellow. This species of locust prefers to live in the tropics and subtropics: it is found in North Africa, on the Arabian Peninsula, on the territory of Hindustan and the border regions of the Sahara.

Italian Locust or Italian Prus (lat. Calliptamus italicus). The body of an adult locust of this species is medium in size: in males, the body length varies from 1.4 to 2.8 cm, females can reach 4 cm in length. The wings are powerful, strongly developed, with rare veins. The colors of individuals are multifaceted: brick red, brown, brown, sometimes pale pink tones predominate in color. Often, light longitudinal stripes and whitish spots are expressed on the main background. The hind wings and femurs of the hind limbs are pinkish, the tibiae are red or whitish, with transverse stripes of black or dark brown. The habitat of the Italian locust covers almost the entire Mediterranean zone and a significant part of Western Asia. The Italian Prussian lives in central Europe and in Western Siberia, lives in Altai, Iran and Afghanistan.

rainbow locust (lat. Phymateus saxosus)- a species of locust that lives on the territory of the island of Madagascar. Incredibly bright in color and very poisonous, the rainbow locust reaches a size of 7 cm. The entire body of the insect shimmers with a variety of colors - from bright yellow to purple, blue and red, and is saturated with toxins. They are produced due to the fact that the locust feeds exclusively on poisonous plants. Usually, large populations of this species of locust are found in the foliage of trees or in thickets of milkweed, the juice of which is a favorite delicacy of the rainbow locust.

Siberian filly (lat. Gomphocerus sibiricus)- an insect of brown-brown, olive or gray-green color. The size of an adult female does not exceed 2.5 cm, males are rarely larger than 2.3 cm. The habitat is very wide: the Siberian filly lives in the highlands of Central Asia and the Caucasus, is found in Mongolia and northeast China, northern regions of Russia, in particular, in Siberia and in the north of Kazakhstan. The insect causes large-scale damage to crops of grain crops, pastures and haylands.

Egyptian filly (lat. Anacridium aegyptium)- one of the most large species locusts living in Europe. Females grow up to 6.5-7 cm in length, the sizes of males are somewhat more modest - 30-55 mm. The color of the insect can be gray, light brown or greenish-olive. The tibiae of the hindquarters are blue, while the femora are bright orange, with distinctive black markings. On the eyes of the Egyptian filly there are always pronounced black and white stripes. This species of locust lives in the Middle East, in European countries, in North Africa.

blue-winged filly (lat. Oedipoda caerulescens)- medium-sized locusts: the length of an adult female is 2.2-2.8 cm, the male is slightly smaller - 1.5-2.1 cm in length. The filly's wings are very spectacular - bright blue at the base, becoming colorless towards the top. On the surface of graceful wings passes beautiful drawing, consisting of the thinnest radial stripes of black color. The lower legs of the hind limbs are bluish in color, covered with light spines. The blue-winged filly is widespread in the steppe and forest-steppe regions of Eurasia, lives in the Caucasus and Central Asia, is found in Western Siberia and in China.