Locust invasion - natural disaster
How to treat the invasion of the hordes of locust? What is it: a natural disaster or punishment from heaven? Why insects suddenly stray into a flock and destroy all vegetation in their path? All these questions periodically arise after the next message that a winged attack is rampant somewhere. These questions have answers, you just need to know where to look ...
Introducing the insect
Locust - not one, but several species of insects belonging to the family of these locusts. The main feature is the presence of two vital phases:
- The first is a low-active single phase. The insect during this period has a greenish protective coloration and a noticeable sexual dimorphism (sex difference). Most often it is called a filly in this period. The solitary existence of a filly is justified in those years when there is enough food to maintain the population size. But if food is not enough, then insects will set aside “hiking” offspring capable of migrating.
- The second phase is active and gregarious. From flocks of larvae numerous flocks are formed. Insects have a bright and contrasting color, at the imago stage they are perfectly adapted to flight, but sexual dimorphism is almost not noticeable. In the gregarious phase, insects are noticeably larger, and the wingspan is significantly larger. A swarm of locusts can be so large that it can be compared to a “living cloud”. The area of such "clouds" sometimes covers up to 1000 km².
Why locusts migrate
Locust invasion is a real disaster for the agriculture of any country. The question of why these insects are derailing has been asked by many generations of scientists. Experimentally it was found that sedentary insects lay offspring that can migrate long distances, with a lack of food. The signal factor here is the population density.
Recent studies have found that the transfer of settled fillies to locusts is due to a lack of protein in the diet. In this part of the insect begins to replenish the protein, attacking the relatives, and some - running away from the cannibal predators. But, which is characteristic, and thoseand others in the herd phase are reinforced by carbohydrate-containing food, that is, they eat up all the vegetation in their path. This is what makes the locust invasion a real disaster.
Experiment with a mirror
In the course of the experiments, scientists were able to establish the effect of population density on the transition of fillies to the herd phase of locusts. To this end, a mirror was installed on the site with settled fillies. Insects perceived numerous reflections as part of the population and laid eggs with a “hiking” program.
In a real situation, when the population increases, insects not only see other fillies, but also get more tactile and chemical contact with them. All this leads to an increased secretion of seratonin in neurons, stimulating a change in the vital phase.
Today, a massive locust invasion happens less and less. People have learned to use insecticides and spray them over large areas with the help of aviation. But in the past it was a real disaster. So, in the years 1874-76, the west of the United States suffered huge losses (more than $ 200 million). Another major invasion occurred in 1915 in Palestine.There were so many insects that they ate not only vegetation, but even clothes made of cotton fabric. By the way, the daily amount of food eaten by each individual exceeds its weight. Therefore, a swarm of locust destroys vegetation completely.
Contrary to the attempts of man to resist invasions, mass migrations occur today. So, in 2001, the Stavropol region of Russia suffered from locusts. In the same year, large parts of China suffered from hungry insects. In 2006, a locust invasion occurred in several US states (Nevada, Utah, Idaho). And African countries suffer from this natural disaster almost every year.
Locust in Russia
Locust invasions of Rus are mentioned in the old chronicles. Large herds of insects migrated to 1008, 1094, 1095, 1195.
In 1824, the Tauride province (the territory of modern Ukraine) suffered from the hordes of these insects.
And in 2001, a locust invasion in the Stavropol Territory led to the introduction of an emergency regime. Equipment and aircraft were thrown at pest control. Insecticides treated more than 350 thousand hectares of land.
And what's the punishment of heaven?
The assertion that the invasion of the locust is a heavenly punishment has deep roots. The Old Testament describes 10 Egyptian executions, among which hordes of locust sent to Pharaoh’s land were the worst. In the description of this punishment it is said that "the locust covered the face of the whole earth." She carried devastation and famine, punishing Egypt for the oppression of the sons of Israel. Pharaoh begged Moses for intercession before God, and the locust retreated.
This biblical story today stirs the minds of many believers. That is why the locust invasion is often called the "heavenly punishment."
In conclusion, it should be said that mankind from year to year tries to improve methods of dealing with aggressive locust migration. Recent developments - insecticides that block the production of seratonina, which will help regulate the number of insects, not allowing them to postpone the "hiking" offspring.