The locust insect is a specific species of short-horned grasshopper in the family Acrididae. They have a swarming stage. Usually solitary, but under certain circumstances they gather in large groups.
There is no taxonomic distinction between locust and grasshopper species. The basis for the determination is whether the species forms swarms under suitable conditions.
Locusts are harmless if their numbers are small. It does not pose a serious threat to agriculture. However, under conditions of drought accompanied by rapid growth of vegetation, serotonin in their brains creates a dramatic set of changes: they begin to reproduce vigorously, gather in groups and move long distances when their populations become dense enough.
They form groups of wingless nymphs, which later form flocks of winged adults. The swarm moves and quickly deprives fields of vegetation and destroys crops. Adults are excellent pilots. They travel long distances, consuming most of the green vegetation wherever they settle.
The ancient Egyptians carved images of locusts on their graves. The insect is mentioned in the Iliad, the Bible, and the Koran. Swarms destroyed crops, caused famine and human migrations.
Today, improved surveillance of areas where groups of insects usually occur can help prevent their emergence at an early stage. Traditional controls rely on the use of insecticides from the ground or from the air. Other methods using biological control are effective.
The formation of locust swarms decreased in the 20th century, but despite modern monitoring and control methods, the potential for their formation remains. When suitable climatic conditions arise and vigilance is lost, epidemics occur.
Locusts are large, edible insects that are considered a delicacy in many countries. The word "locust" comes from the Latin Vulgate locusta, which means grasshopper.
How does a swarm form?
The swarming phase is present in some species of grasshoppers of the family Acrididae. These insects are usually solitary, but under certain circumstances they become numerous, change behavior and habits, becoming sociable.
There is no taxonomic distinction between locust and grasshopper species. The basis for the determination is whether the species forms swarms under suitable conditions.
These changes are examples of phase polymorphism. Analyzed and described by Boris Uvarov, who played an important role in the creation of the Locust Control Center.
Swarming behavior is a response to overcrowding. Increased tactile stimulation of the hind legs causes an increase in serotonin levels. This causes the insect to change color, eat much more, and reproduce much more easily. The transformation into the swarming form is triggered by multiple contacts per minute over four hours.
A large swarm may consist of billions of individuals scattered over thousands of square kilometers. Consists of 80 million per square kilometer. When insects meet, their nervous systems release serotonin, which causes them to attract each other. This is a necessary condition for swarming.
During outbreaks and the early stages of the rise, only a portion of the population becomes gregarious, with scattered bands over a large area. Over time, the insects become more united, the stripes are concentrated in a smaller area.
During the desert locust plague in Africa, the Middle East, and Asia, which lasted from 1966 to 1969, the number of locusts increased from two to 30 billion in two generations. The covered area has decreased from more than 100,000 square kilometers to 5,000.
3) African Siafu ants
One colony of these ants, which consists of 20 million individuals, can devastate an entire African village, destroying everything in its path. When there is not enough food, the siafu colony begins to eat everything they can find in order to somehow survive. The ants can kill animals and humans and cause thousands of dollars in damage each year as they destroy Africa's valuable food supply.
Behavior, how to eat
One of the biggest differences between the solo and group phases is behavior. Nymphs are attracted to each other in the second instar. Soon, groups of many thousands of individuals are formed. The swarm behaves as a cohesive unit, moving across the landscape, often downhill.
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Sneaks through barriers and merges with other groups. The attraction between insects is observed visually. It includes olfactory signals, the group moves using the sun. They pause to feed at intervals before resuming their march. They cover tens of kilometers in a few weeks.
Differences in morphology and development are observed. For example, the desert locust and migratory locust become darker in color with highly contrasting yellow and black markings. They have longer periods of development.
Adults are larger, with different body proportions, less dimorphism, and a high metabolic rate. They mature faster, begin to reproduce earlier, but have a lower level of fertility.
Mutual attraction between individual insects continues into adulthood. They continue to act as a cohesive group. Individuals separated from the swarm fly back into the mass. As the insects at the front of the swarm settle down to feed, others fly over them.
After lowering themselves, the entire swarm acts as a rotating unit with a constantly changing leading edge. Locusts spend a lot of time on the ground, feeding and resting, moving when the vegetation is depleted. They fly a considerable distance before settling in place.
4) Wasps
Wasps are known to many people all over the world. These social insects with a bright yellow body and long antennae hunt parasites and pests, with each individual subspecies having its own prey. However, a wasp sting can be very dangerous for humans, as it is very painful and often causes allergic reactions. Some stung people go into anaphylactic shock and can die from just one wasp sting.
Distribution, diversity
Several species of grasshoppers swarm like locusts in different parts of the world, on all continents except Antarctica and North America.
Desert (Schistocerca gregaria) is best known due to its wide distribution (North Africa, Middle East, Indian subcontinent) and ability to migrate over long distances. The first outbreaks occurred in Mauritania, Mali, Niger, and Sudan in 2003.
The rain allowed the swarms to grow and move north. He crossed Africa, appearing in Egypt, Jordan, Israel, for the first time in 50 years. The cost of treating the infestation is US$122 million. Crop damage - up to 2.5 billion dollars.
The migratory locust (Locustu migratoria) has up to 10 subspecies. Characteristic of Africa, Asia, Australia, New Zealand. It has become a rarity in Europe. Madagascar's migratory locusts have formed swarms of more than a billion insects, covering about half the country by March 2013.
North America is the only continent other than Antarctica that does not have swarming locusts.
10) Malaria mosquitoes
Mosquitoes are terrible irritants because they suck blood and can drive a person crazy under certain conditions. They lay their eggs near stagnant bodies of water, and from one clutch millions of individuals are born. However, the biggest problem is that mosquitoes can carry dangerous diseases such as malaria. Thousands of people die from this disease every year; these mosquitoes are the most dangerous and deadly insects on the planet.
Interaction with people
Ancient times
A study of the literature reveals how common locust epidemics have been throughout history. Insects appeared unexpectedly, often after a change in wind direction or weather. Had devastating consequences.
The ancient Egyptians carved it on tombs (2470 – 2220 BC). A devastating plague of locusts is mentioned in the Book of Exodus of the Bible. Parasite invasions are mentioned in the Koran. In the ninth century BC, Chinese authorities appointed officers to combat it.
Aristotle studied locusts and their reproductive habits. Livy, 203 BC, Capua, recorded devastating invasions. He mentioned human epidemics after locusts, which he associated with the stench of rotten corpses.
The association of human disease outbreaks with locust epidemics is widespread. In the northwestern provinces of China, 311 AD, a plague epidemic was destroyed, which was caused by an increase in the number of rats (and their fleas) that devoured the carcasses of locusts.
Watch the video - locust invasion
Present tense
The main reported outbreaks occurred in Africa, the Middle East, and Europe. Since 1924, 173 outbreaks have been reported in China. The Bombay locust (Nomadacris succincta) is one of the main pests of India and Southeast Asia in the 18th and 19th centuries. Rarely swarmed after the last plague of 1908.
In the spring of 1747, locusts arrived outside Damascus. Ate most of the crops and vegetation of the surrounding area. A local hairdresser, Ahmad al-Budayri, recalled that “I came like a black cloud. Covered everything: trees, crops.”
The disappearance of the Rocky Mountain locust has become a source of confusion. In the 19th century, it covered the entire western United States and some areas of Canada.
Albert's 1875 swarm covered 198,000 square miles (510,000 km2), larger than California. Weighed 27.5 million tons with approximately 12.5 trillion insects. Last specimen seen alive in Canada, 1902.
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The insect's breeding grounds in the Rocky Mountain Valley were under sustained agricultural development during a large influx of gold miners, destroying the parasite's underground eggs.
Reproduction
The beginning of reproduction depends on the habitat. In temperate climates, lovemaking begins in late spring or early summer. At this time, the males emit loud trills.
At this point, they have seminal fluid in the form of a capsule, which is necessary for reproduction.
At the moment of reproduction, the male attaches a sticky bait - a capsule - to the female's abdomen. While she eats it, the liquid gradually enters her oviduct.
After fertilization, the female lays eggs on her own, which can contain from 100 to 1000 eggs. Then larvae appear, resembling a small grasshopper.
During growth, the grasshopper molts from 4 to 8 times. After the last molt, the insect waits until its wings get stronger. The insect lives only one season.
Monitoring
Early intervention is more successful in controlling locusts than late action once swarms have already formed. Technology for population control is available, but organizational, financial, and political problems are sometimes difficult to overcome.
Monitoring is the key to reducing damage, and the goal is early detection and eradication. Achieving the goal is possible in rich countries such as Morocco and Saudi Arabia.
Neighboring poor countries (Mauritania, Yemen) do not have the resources to serve as a source of epidemics that threaten the entire region.
Several organizations around the world are monitoring the locust threat. Provide forecasts detailing regions likely to be affected by a locust outbreak in the near future.
FAO is monitoring the situation in the Caucasus and Central Asia, where more than 25 million hectares of arable land are under threat.
9) Fleas
If you have cats or dogs at home, you know very well what fleas are, and you also know that they can bite not only pets, but also their owners. Fleas spread bubonic plague
, which can be transferred from rats to humans.
This disease is caused by the bacteria Yersinia pestis
. Fleas feed on the blood of warm-blooded animals and reproduce at tremendous speed. Flea bites can cause allergic reactions.
How to get rid of it, control methods
Historically, people could do little to protect crops from locust devastation. But eating insects was a consolation. To disrupt the development of insects, the soil where the eggs are laid is treated.
It is destroyed with flamethrowers, mechanical devices, and other methods. By the 1950s, the organochlorine dieldrin was established to be an extremely effective insecticide. It was later banned in most countries due to persistence in the environment and bioaccumulation in the food chain.
To kill locusts, water-based contact pesticides are used using sprayers. The method is effective, but slow and labor-intensive. Where possible, spraying concentrated insecticide solutions from aircraft onto insects or feeding vegetation is preferable.
The use of ultra-low volume sprays of contact pesticides from aircraft in overlapping stripes is effective against nomadic stripes. Used for quickly processing large areas of land.
Other modern technologies are GPS, GIS tools, satellite imagery. Computers enable rapid data management and analysis.
A biological pesticide that kills locusts was tested in Africa, 1997. Dried fungal spores of Metarhizium acridum are sprayed onto nesting sites. They penetrate through the exoskeleton into the body cavity, causing death. The fungus is transmitted from one insect to another.
It persists in the treated area, making re-spraying unnecessary. The approach was successfully used in Tanzania, 2009, to treat approximately 10,000 hectares of Iku-Katavi National Park infested with adult locusts. Elephants, hippos and giraffes present in the area were not harmed.
The ultimate goal in locust control is to use preventive, proactive methods that are less disruptive to the environment.
Grasshopper color
The color of the insect will depend on the habitat in which it lives. That is why you can find green, brown and even striped colors.
One of the characteristics of the grasshopper is the location of its ears. They did not have enough space on their heads, like many representatives of other insects. Therefore, the ears are located on the front legs in the area of the lower leg.
In the same place are the eardrums, which perform their direct function. When the front legs are lost, hearing is correspondingly lost. Legs are especially precious to him.
Is it possible to eat locusts
Locusts are edible insects. Several cultures around the world consume the insect and it is considered a delicacy. Used in many African, Middle Eastern, Asian countries. Used as food throughout human history.
It is prepared in a variety of ways, but is often fried or dried. The Bible records that John the Baptist ate locusts and wild honey while living in the desert. Attempts have been made to recognize it as an ascetic vegetarian food, such as carob beans, but have failed. These are locusts - insects.
The Torah prohibits the use of most insects as food, but allows the consumption of kosher locusts. For example, red, yellow, gray spotted and white are considered acceptable. In Islamic tradition, locusts are considered halal. The Islamic prophet Muhammad ate it during a military raid with his companions.
Locusts are eaten in the Arabian Peninsula, including Saudi Arabia. Abd al-Salam Shabin described a recipe for locusts from Morocco. European travelers of the 19th century observed the Arabs of Arabia, Egypt, and Morocco selling, cooking and eating locusts. They reported that the insect has been destroyed in Egypt and Palestine, and Syrian peasants do not eat it.
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The insect has approximately five times more dietary protein than cattle. A 100 g serving of desert locust provides 11.5 g of fat, 53.5% of which is unsaturated, and 286 mg of cholesterol. Among the fatty acids there are palmitoleic, oleic, and linolenic acids. Contains potassium, sodium, phosphorus, calcium, magnesium, iron, zinc.
Insect diet
For the most part, locusts spend their time on leaves, flowers, and grass. Locusts are the most vegetarians without any obvious food preferences. Most species do not care what kind of crop it is - wild or agricultural. They feed on the leaves of plants, trees, shrubs, and all ground parts of plantings. Only some species prefer herbaceous plants. During its life, an insect eats an average of 300-350 g of plant mass, and the daily volume is twice its own weight.
For some species, poisonous plants serve as food. As toxic components accumulate in the locust's body, it becomes poisonous. These individuals are characterized by bright, flashy colors, which seem to warn of the danger of everyone who wants to feast on locusts.
When insects gather in swarms, what the locusts feed on depends on the objects that come across its path. In this case, even thatched roofs and reeds, not to mention vegetables, grains, and melons, can be eaten. As eyewitnesses say, during insect attacks, locusts only devour bricks and iron.
The insect is bred as food for various exotic animals. Therefore, the question of what locusts eat at home does not surprise anyone. In insectariums they are fed twice a day with grain, green herbs, and some owners even prepare sprouted wheat for their pets.
List of locust species
A list of locust species that form groups and cause significant economic damage to crops.
- Australian plague, Chortoicetes terminifera;
- Bombay, Nomadacris succincta;
- Brown, Locustana pardalina;
- Desert, Schistocerca gregaria;
- Italian, Calliptamus italicus;
- Migratory, Locusta migratoria.
- Red, Nomadacris septemfasciata;
- Rocky mountain locust, Melanoplus spretus – extinct;
- Woody: Anacridium spp. – Anacridium aegipitum, melanorhododon, Wernerellum;
- Ceracris kiangsu: yellow bamboo locust - Indochina, eastern China.
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.
Moroccan locust
The Moroccan locust, Dociostaurus maroccanus, is found in northern Africa, southern and eastern Europe, and western Asia. In Europe it is found in France, Portugal, Spain, Italy, and the Balkan Peninsula. Lives alone, but after a few years the number increases sharply, becomes sociable, and unites, forming swarms. The species was first described by Thunberg, 1815.
What does it look like
Eggs are laid in pods of 30 eggs. Nymphs resemble wingless adults. They molt five times, each age having larger wing flaps. An adult female locust is 20–38 millimeters long, males are 16–28 millimeters long.
The body color is yellowish-gray with dark spots. There is a cream-colored cross shape on the chest. The elytra are large, transparent, sometimes spotted with brown. The wings are colorless, with veins.
The hind legs are powerful, the femur is black, the lower leg is red. The maturation time from nymph to adult is thirty days.
Behavior
It nests on undisturbed soil and does not breed in arable fields. The optimal amount of precipitation for development is one hundred millimeters. If the spring is unusually hot and there is little rainfall, the number of young insects increases sharply.
Swarms move downhill towards fertile areas, damaging crops. There are several generations in the swarm, the number of adults increases rapidly, reaching 300 per square meter. The winged adults fly at low altitudes, traveling at speeds of eight to ten meters per second.
They migrate sixty kilometers per season. The number decreases in June, when the vegetation disappears.
Ways to fight
Protective measures against this pest include:
- Number counting and forecast.
- Agrotechnical methods of soil cultivation. These include deep harrowing in late autumn or early spring. On private plots - digging up the earth.
- Chemical methods. This includes both aerial and ground spraying of insecticides.
- Mechanical methods. They include manual collection when pest numbers are low. When a flock forms, they are shot using sandblasting machines.
Borderline species
- The Senegalese grasshopper, Oedaleus senegalensis, exhibits locust-like behavior in the Sahel region;
- Sudan plague, Aiolopus simulatrix - behaves like the locust of eastern Sudan;
- Highland grasshopper, Dissosteira longipennis - exhibits similar behavior to the 1930s epidemic;
- Pale-winged grasshopper, Trimerotropis pallidipennis - occasionally exhibits swarming behavior in western North America, most recently in Nevada, 2022.
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.
Do locusts bite?
Locusts can bite if handled or through prolonged contact, but they have no venom. It does not specifically bite people, like mosquitoes or ticks, because it feeds on plants.
If you do get bitten by a locust, it cannot bite through your skin. The worst thing you'll feel is a prick or like you've been pinched. This is how the insect protects itself.
6) Fire ants
Usually nesting in sand or soil, fire ants build fairly high anthills and feed mainly on plant foods, sometimes on crickets and small insects. If disturbed, they can sting painfully, and their bite is similar to the sensation of a burn, hence the name. Small bites of one or two ants can be easily and quickly cured, but if you are attacked by a whole family of angry ants, expect trouble. These ants are reported to kill up to 150 people every day and also damage crops.
