Translated material
The schooling hormone
A way to fight locusts has been found
British and Australian researchers have made an important discovery that will help fight the hordes of locusts devastating fields. Scientists have found that changes in the level of the hormone serotonin in the body of insects affects their behavior.People have been fighting locusts for a long time. Back in Old Testament times, God threatened to send the eighth plague—locusts—on the Egyptians who did not want to release the Jews from captivity. The stubborn pharaoh did not listen to the threat and refused to release the captives. The east wind blew all day and all night, and the next morning locusts attacked the land of Egypt. She covered the whole earth and ate all the grass and all the fruits.
Thousands of years have passed since then, but locusts are still perhaps the most important enemy of agriculture today.
Now the scales in the centuries-long war between humans and locusts seem to have begun to tip towards humans. Scientists from Oxford, Cambridge and Sydney universities have found a way to combat voracious insects.
Strange as it may seem, locusts are solitary by nature and prefer not to communicate with their relatives. The transformation of Dr. Jekyll into Mr. Hyde begins after the rains. Lush vegetation causes insects to multiply intensively. Then, after the inevitable drought, the surviving locusts, in order not to die of hunger, willy-nilly begin to flock to the “islands” of greenery that are getting smaller every day, gathering in large groups. From loners they turn into schooling insects. At the same time, physical changes also occur - insects change color and build muscles, preparing for long-distance forays into fertile lands where there is plenty of food.
British and Australian scientists have found the catalyst for an amazing transformation. This is the hormone serotonin, which regulates the character and behavior of living beings, including humans.
Serotonin accumulates in nerve endings located in the middle part of the locust's body. There are nerve centers that control the movements of the legs and wings. Moreover, the accumulation of the substance occurs almost instantly, within just two hours.
The research results, published in the latest issue of the journal Science, give hope for an early victory. According to scientists, in order to “disperse” a flock, it is necessary to block the action of serotonin, which changes the behavior of insects. This can be done using other chemicals. Places where locusts gather can be treated with a spray containing this substance, after which the swarms should theoretically disintegrate.
On a day, locusts eat as much as they weigh - up to 2 grams. Whether this is a lot or a little can be judged at least by these figures. Experts from the UN Food and Agriculture Organization (FAO) have calculated that a ton of locusts eats as much as 2.5 thousand people per day.
During the last major locust invasion (1986-1989), hordes of voracious insects, stretching for hundreds of kilometers and occupying an area of 1 thousand square meters. kilometers, devastated fields over vast areas from India to Mauritania. According to scientists, this “army” consisted of 40 billion insects, which weighed about 80 thousand tons. Using simple arithmetic calculations, it can be calculated that 20 years ago locusts left 200 million people without food.
Female locusts lay up to two hundred eggs in their lifetime, which take two to three weeks to grow into winged insects capable of beginning reproduction.
Farmers in different countries have to deal with the problem of locusts; they raid all continents except Antarctica.
Large locust invasions occur every 10-20 years, when weather conditions favor increased reproduction of these voracious insects.
Locusts are highly maneuverable and can fly more than 130 kilometers in a day. In 1954, for example, a huge flock (entomologists call a flock a group of at least 80 million insects) managed to move from North Africa to... Great Britain.
In 2004, Mauritania lost half its harvest to a locust outbreak. Having devastated this African country, a huge swarm of insects, estimated at 100 million in number, flew across part of the Atlantic Ocean and scared the life out of vacationers on the beach of the island of Fuerteventura, part of the Canary Islands archipelago.
Of the latest invasions, Australia should be noted, where in November 2008, a swarm of locusts stretching over 6 km turned a number of areas of the Green Continent into desert.
Until recently, locusts were fought mainly with the help of environmentally hazardous chemicals, but after the ban on the most powerful pesticide, DDT, it became even more difficult to control locusts. Quite exotic means of struggle were also proposed: using giant nets, flamethrowers, lasers and even huge... vacuum cleaners.
Birds and people eat locusts with pleasure, but there are so many insects that these losses have virtually no effect on their numbers. Several years ago, the Chinese really hoped for a secret weapon - trained ducks, capable of eating up to half a kilogram of harmful insects a day, but the birds did not live up to the trust placed in them.