Material overview
A person receives information about the world around him through vision, hearing, smell and touch. Research by scientists has shown that for a newborn child, the most important of all senses is smell, and when a person grows up, primacy passes to vision. We decided to find out which sense is the most developed in animals? Find out what significance the sense of smell of animals has for humans. Some animals have very acute hearing, others have vision. But distinctive feature Most animals have an amazing sense of smell, that is, a very sensitive perception of smells.Purpose of the work. Find out what importance the sense of smell of animals has in human life.Job objectives:
1. Study literary and Internet sources on the research topic.
2. Find out what the sense of smell is.
3. Determine which animals have the most acute sense of smell.
4. Conduct an experiment to study the acuity of smell in animals.
5. Find out how people use their pets' keen sense of smell.
Hypothesis:
Animals' sense of smell helps humans.
Research methods:
Studying literature and Internet resources on the research topic
Method of observing living objects
Analysis of the results obtained
Survey of students of different ages on the research topic
Theoretical part
1.What is the sense of smell
The sense of smell is the ability to perceive particles of odorous substances using special sensitive cells. In higher animals, the nose is the organ of smell. Fish do not have a nose, but openings - the nostrils - lead into olfactory sacs dotted with sensitive cells. Such cells are called receptors. Olfactory receptors have 10-12 cilia. The cilia move and push air with particles of odorous substance into the olfactory organ. In the receptor, under the influence of odorous particles, a nerve impulse is formed, which runs through the nerves, like current through wires, to the brain. There is a special olfactory zone in the brain where information from all olfactory receptors flows. The brain analyzes information and forms a response. For example: the olfactory receptors of the dog’s nose caught the smell of the owner going up the stairs. The brain gives a command to the dog's legs, and it runs to the door to meet the owner.The sense of smell is developed in most animals, but to varying degrees. Based on the sensitivity of smell among mammals, three groups can be distinguished:
Macrosomatics - their sense of smell is very well developed (dogs, rats, cats and other animals)
Microsomatics - the sense of smell is much less developed compared to the first group (seals, baleen whales, primates, which includes humans)
Anosomatic - no olfactory organs (toothed whales)
Cats and dogs are pronounced macrosomatics. The owners of these animals tell amazing stories about sensitivity to odors in their pets. The cat of the director of this work has never been outside. While walking on the second floor balcony, she fell down. When the owner came home, she did not find the cat. For a whole week she was homesick without her pet. Suddenly in the evening I heard meowing and scratching outside the door. Opening the door, she saw a dirty, emaciated, but happy cat on the threshold, which, with a loud purr, began to rub against the legs of its owner. The balcony faced the opposite side of the door. The house had six entrances, the apartment was located in the second entrance on the second floor. How could a cat find the right entrance and the right door? Only by the smell, because she never went out through the door onto the street. And another one amazing story. In the family of a disabled man there lived a cat and a cat. He was bedridden, and his wife worked long hours and came home at different times. She arrived by bus and walked exactly five minutes from the stop. The cats sensed their owner's approach from the minute she got off the bus. They raced to the door and took a wait-and-see attitude. Exactly five minutes later the hostess appeared. You could set your watch by looking at the animals. The owner always knew that his wife was approaching the house by the behavior of her pets.
2. Why do animals need smell?
The sense of smell plays a huge role in the lives of animals.
1. With the help of smell, many animals search for and select food.
2. Predators track prey by smell
3. Ungulates and rodents smell the enemy and flee or hide in burrows
4. With the help of smells, animals communicate, determine the boundaries of their territory, and find each other during the breeding season.
Not only higher animals have a developed sense of smell. Many insects are also different in this way. Olfactory receptors are located on their antennae and paws. The sensitivity of some insects is amazing. An example of a level of sensitivity so far unsurpassed is the “olfactory locator” of the silkworm. The fluffy antennae of the male catch in the air single molecules of a substance secreted by the female 10 km away. Insects such as ants leave scent trails to help their fellows find a food source, and when in danger, they leave the “smell of death.” Ants also determine the shape of objects by smell. Among birds, the New Zealand kiwi bird uses its sense of smell, which with its long nose “sniffs out” insects, worms, etc. Fish use their smell to navigate the water and migrate from rivers to seas and vice versa. A shark can smell blood in the water several kilometers away.
4.The sense of smell of animals in the service of humans
Very often, an ordinary person, in order to cope with a particular situation, needs to have special, unique abilities. And people solve such problems with the help of their little brothers.Nature has not been very generous to humans as far as the sense of smell is concerned. But in dogs this sense is developed, about 12 times more and much sharper than that of us “homosapiens” and some mammals living on Earth.Probably, many of you have watched the cartoon “The Cat Who Walked By Itself”, a film adaptation of one of the fairy tales of the famous writer Kipling. The plot clearly and clearly shows how ancient man began to “cooperate” for his own benefit with many animals. And one of the first who began to serve people was a dog. Our ancestors noticed that the dog has a highly developed sense of smell, as well as hearing and vision. She has, among other things, excellent endurance and extreme fighting qualities: this is someone you can hunt and hike with for months. Moreover, not a single creature living on Earth can be trained as strongly and quickly as a dog.Man widely uses animals with a keen sense of smell to perform different types jobs in which this feeling is necessary. This is how animals acquire “professions” and help humans. Most often, dogs do work for humans. There are several reasons for this:
dogs have a very good sense of smell
dogs are easy to train
dogs are loyal to their owner
Let's look at some of the professions of dogs:
Hunting dogs
Chasing prey or participating, for example, in baiting hares. Dogs either rely on scents released through the air by animals or focus on scents from their tracks. In the first case, the dog usually does not exactly repeat the path of its victim - after all, the wind carries the smell to the side. Meanwhile, a dog, following exactly the trail of a hare, reacts, of course, not only to the spirit of the animal, but also to the odors that arise when the hare's paws come into contact with grass, moss and other objects. In other words, the smell of vegetation or soil is no less important for a dog than the smell of the prey itself. Most hunting breeds suitable for rounding up have an amazing, by human standards, ability to quickly recognize in which direction, for example, the tracks of a hare lead. This gift, presumably, is mostly innate and cannot be interpreted otherwise than as the ability to instantly determine in which direction the smell of an animal weakens and in which it intensifies. An experienced dog only needs to sniff the trail for just a few meters to understand the situation. This confirms the dog's ability to detect the slightest differences in the intensity of odors emanating from the pursued animal or from its tracks. True, an inexperienced dog may follow a false scent for tens of meters before it discovers the mistake. But soon she also begins to recognize the direction the victim is following.
Border guard dogs
The Russian army actively began to use dogs in border guards in the mid-19th century. Since then, day and night, regardless of the weather, dogs have been on guard duty at the border. Dogs of various breeds are raised in kennels for the search service. There are Eastern European and German shepherds, spaniels, Labradors and other breeds. However, priority goes to the East European Shepherd. She is the most convenient to work with because she is easy to train, is distinguished by strength and power, and is able to protect the owner and detain the enemy. The dog's unusually developed sense of smell is capable of distinguishing up to 12 thousand odors. Each dog has its own narrow specialization, some are trained to search for drugs, others search for weapons and explosives. Small breed dogs are used to inspect small spaces; a shepherd dog is suitable for inspecting trains. There is an opinion that drug-detecting dogs search for drugs. However, training is based on play and the search for a drug for a dog is an exciting procedure, the interest in which is constantly maintained by the owner. For training, a “bookmark” containing a narcotic substance is specially created.
Most of the dogs used at the border are the personal dogs of border guards. To this day, there are children's clubs where future border guards are trained and dogs are raised. The guys learn military wisdom, train their pets, and when the time comes, they serve together on the border.
Rescue dogs
The first rescue dogs appeared several centuries ago. Then their main purpose was to search for lost travelers during a snowstorm. For several hundred years, such dogs were bred in France in the monastery of St. Bernard by crossing Newfoundlands and Great Danes. These St. Bernard dogs are often depicted with a small keg of brandy around their neck. You, of course, ask - why? Dogs of this breed left the monastery every day in search of travelers who had lost their way, and a barrel of wine or other strong drink hung around their necks. Having found a lost and frozen traveler, they gave him warm wine to drink from a barrel so that the traveler could quickly warm up.It is impossible to count how many people the St. Bernards saved. But the most popular among them was a St. Bernard named Barry. The story about him has long become a legend. Barry sensed the approaching snowstorm intuitively more than an hour before it started, and became very restless. One day he saved a child who was deep under an avalanche, and no one even suspected that he was in trouble except Barry. Barry found the child and licked his face until the child came to his senses. Fate played a cruel joke on Barry. If you believe the stories about the legendary dog, Barry saved forty people, and was killed forty first. One day, Barry once again discovered an almost frozen man. Having dug him out, the dog lay down next to him to warm the victim with his body. When the man came to his senses, in the dark he mistook Barry for a bear and seriously wounded him. Despite the serious injury, the dog made it to the monastery, where he received medical assistance. He remained alive, but due to his wound he could no longer save people. He was taken to Bern to an animal hospital. After Barry's death, a monument was erected to him in one of the Parisian cemeteries. A huge fluffy dog was captured with a child trustingly clinging to him on a stone pedestal with a memorable inscription: “Barry, who saved forty people and was killed forty-first.” Hero dogs are now called those who helped people during hostilities. They were full-fledged fighters and took part in the search for missing people under the rubble, cleared mines, and worked as messengers. Dogs were first used to search for people under rubble during the Second World War after the bombings in Great Britain. The first centers for training search and rescue dogs appeared in the mid-50s. Dogs performed an important and responsible mission during the Great Patriotic War. Their exploits are difficult to overestimate. They have saved thousands of lives. Many four-legged warriors have gone down in history. The collie dog Dick was trained in mine detection. In his personal file there was the following entry: “Called up for service from Leningrad. During the war years, he discovered more than 12 thousand mines, took part in demining Stalingrad, Lisichansk, Prague and other cities.” But Dick accomplished his main feat in Pavlovsk. He discovered a two and a half ton landmine with a clock mechanism in the foundation of the ancient palace an hour before the explosion. After the war, Dick participated in many exhibitions. He died of old age and was buried with full military honors, as befits a hero. Nowadays, German shepherds are most often used for rescue work after avalanches to search for victims under the rubble, as well as after earthquakes and other natural disasters. They adapt best to extreme conditions weather conditions, and are also amenable to even the toughest training. Saint Bernards specialize in rescuing climbers and skiers. If the search for the missing is carried out on land, the dog can report in three ways that it has found a person: to give a voice, to take something from the rescued person and return with help, to be between the owner and the victim. The hardest part is finding people under the rubble. The dog must clearly detect the human scent from a mass of others and detect the victim from under the meter-thick rubble. Training rescue dogs is a rather complex process. The methods are being developed by the International Rescue Dog Organization, which is located in Sweden. According to experts, it takes about a year to teach a dog to detect living people and report their location. IN Lately More and more advanced technology is coming to the aid of rescuers, but the most effective and efficient search method still remains the canine method. After all, a dog’s sense of smell and intuition cannot replace even the most innovative technologies. The four-legged rescuer is able to detect even the faintest odors and distinguish them from thousands of unnecessary ones. One rescue dog saves the work of dozens of people. And the furry rescuer’s greatest reward is the salvation of a person, or simply any living creature. And, conversely, when a dog does not find living people, it becomes depressed.
Mining dogs
If dogs with their keen senses are able to find mines hidden underground in the rubble of people, perhaps they can be taught to find minerals?
Such an experiment was successfully performed by the Finnish geologist Professor Kahma on his dog Lari. Lari managed to discover deposits of copper ore. Since 1966, our country also began to use dogs to search for minerals. Employees of the Karelian branch of the USSR Academy of Sciences, with the help of dogs, found tungsten deposits on the Kola Peninsula, nickel deposits in the Ladoga region, and others.Successful sappers: what we know about ratsA group of Belgian scientists decided to conduct experiments with huge African rats, since it is known that these animals have the same keen sense of smell as dogs. They decided to teach these funny little animals to look for anti-personnel mines, because rats are much smaller than dogs, and therefore the likelihood of a possible explosion is too small. The experiment of scientists from Belgium was a success, and subsequently African rats began to be bred specifically so that they would search for mines in Mozambique and other African territories, where, like us, after military operations many shells remained deep in the ground. So, starting in 2000, scientists used 30 rodents, who managed to secure over two hundred hectares of African territory in 25 hours.It is believed that rodent mine detectors are much more effective to use than sappers or dogs. Indeed, a rat can cover two hundred square meters of territory in twenty minutes, while a person will need 1,500 minutes for search work. Yes, and dogs are excellent mine detectors, but they are very expensive for the state (maintenance, services of dog handlers) than small gray “sappers”.
More than just waterfowl: seals and sea lions
At the beginning of the twentieth century, in 1915, Durov V., a well-known trainer in Russia, suggested that the Navy use seals to search for underwater mines. Yes, for the leadership of the Russian Navy it was an unusual, one might say innovative, method. It was believed that only dogs have a highly developed sense of smell, so they can find a mine no matter where it lies. However, since the war, many explosive devices have been found in water resources. And something had to be done about this. And, after all the pros of using seals in the search for water mines were studied, large-scale training of waterfowl began on the Crimean island.
So, in the first 3 months, twenty seals were trained in Balaklava, which, surprisingly, were very trainable. Underwater, they easily found explosives, mines and other explosive devices and substances, marking them with buoys every time. The trainers even managed to teach some “mine detector” seals to place special mines on magnets on ships. But, be that as it may, it was not possible to subsequently test the specially trained seals in practice - someone poisoned the “sea fighting animals”.
Sea lions are eared seals that have excellent underwater vision. Sharp eyes help these cute marine mammals find enemies. The US Navy has spent millions of US dollars training seals as part of a training program to repair a damaged site or detect explosive devices.
But in Irkutsk this year, seals were even specially trained to show how these animals can perfectly hold machine guns in their hands, march with a flag through the water, and even neutralize planted sea mines.
Guarding the world: what dolphins can do
Dolphins began to be trained as special mine detectors after war seals gained enormous popularity at one of the naval bases in San Diego. Scientists from the USSR decided to prove that dolphins, just like sea lions, are capable of benefiting people, like the smartest and bravest “special forces”
In the 60s, in Sevastopol, a large aquarium was created, where dolphins were taught to search underwater not only for mines from the Second World War, but also for many sunken torpedoes. In addition to their ingenuity and excessive intelligence, with the help of transmitting echolocation signals, dolphins are able to carefully examine the situation, everything that is going on around them. Dolphins easily found a military facility at a great distance. As skilled defenders, trained dolphins were assigned to “stand guard” and protect naval bases in the Black Sea
Practical part
II.1. Conducting a survey among schoolchildren of different ages
A cat and a dog were looking for their favorite toy, a ball, by smell. During the game, the ball was taken from the animals, quickly taken to another room and hidden on a high cabinet. When the animals entered the room, they rushed to the closet and demanded that the toy be returned to them: the dog jumped and barked, and the cat scratched the closet and meowed.
Conclusion: The sense of smell in domestic animals is well developed and allows them to search for food and toys.
Our experiment did not allow us to determine which pet has a better developed sense of smell. We resolved this issue with the help of literature. When determining the acuity of smell, two parameters are taken into account: the number of olfactory cells and the range of action. The number of olfactory cells in our subjects was distributed as follows: hamster - 12 million, rabbit - 100 million, cat - 80 million, dog - 240 million, rat - 224 million. Two animals are in the lead in the number of olfactory cells: the dog and the rat, while in rats this number is even higher. But rats only smell long distance. One of the drug control “sensors” at the airport is based on this feature of the rats’ sense of smell. Cages with rats are placed next to the conveyors along which luggage passes. Rats are very sensitive to the smell of drugs and react to it in a certain way.
When the rats in all the cages become restless, as if on cue, the luggage is subjected to a more thorough check. In 98% of cases, “rat control” works flawlessly.
Considering that the rat’s acute sense of smell only works over a short distance, it is inferior to two animals at once: a dog and a cat. Thus, according to the number of olfactory cells and the range of the sense of smell, the animals were distributed as follows:
III. Conclusion
While working on our research, we learned a lot of interesting things about animals, especially pets. We have seen that for most wild animals, the loss of smell is tantamount to death, because they will not be able to track prey and will not sense the approach of an enemy by smell. As a result of the study, our hypothesis was confirmed. The sense of smell of animals is of great importance in human life. As a result of the research, I found out that there are animals that help humans without having a sense of smell. For example, dolphins, just like sea lions, are able to benefit people, as the smartest and most courageous “special forces”, and seals are “mine detectors”. They are called anosomatics.
Our work is relevant for all pet owners: it will help you better understand the behavior of your pets and help with training. We will definitely share our research with our classmates and other students at our school.
When people start talking about the sense of smell in insects, they almost always remember the French entomologist J. A. Fabre. Often the conversation generally begins with Fabre, or more precisely, with an incident that happened to him and which actually served as the discovery of an extraordinary “sense” in insects and the beginning of its research.
One day, in a little garden in Fabre’s office, a Saturnia butterfly, or, as it is also called, a large night peacock eye, emerged from a pupa. This is how Fabre describes what happened next:
“With a candle in my hands, I enter the office. One of the windows is open. We cannot forget what we saw. Huge butterflies fly around the cap with the female, softly flapping their wings. They fly up and fly away, rise to the ceiling, descend down. Rushing towards the light ", they extinguish the candle, sit on our shoulders, cling to our clothes. The sorcerer's cave, in which bats rush like a whirlwind. And this is my office."
And more and more butterflies continued to fly into the open window. In the morning Fabre counted - there were almost one and a half hundred of them. And all are males.
But the matter did not end there.
“Every day between eight and ten o’clock in the evening, butterflies arrive one after another. Strong wind, the sky is overcast, so dark that in the garden you can barely see a hand raised to your eyes. The house is hidden by large trees, blocked from the northern winds by pine and cypress trees, and not far from the entrance there is a group of dense bushes. To get to my office, to the female, Saturnias must make their way in the darkness of the night through this tangle of branches."
Fabre is surprised at how the males found out about the presence of a female butterfly in his office. But he himself answers this question: “Males are attracted by the smell. It is very subtle, and our sense of smell is powerless to catch it. This smell permeates every object on which the female spends some time...”
To make sure whether this is really true or not, Fabre did interesting experience, trying to confuse the butterflies. However…
"I was not able to knock them down with mothballs. I repeat this experiment, but now I use all the odorous substances I have. I place about a dozen saucers around the cap with the female. There is kerosene, and mothballs, and lavender, and fragrant rotten eggs carbon disulphide. By the middle of the day, my office smelled so strongly of all sorts of pungent odors that it was eerie to enter. Will all these smells lead the males astray? No! By three o’clock in the afternoon the males arrived!”
Fabre saw a small drop of liquid that a butterfly secretes during hatching, and realized that the smell comes from this liquid... But then - it’s already beyond reality!
After all, the droplet is tiny, the smell is elusive, and the males are not near the place where the female is - they need to fly from somewhere. Enough to saturate large space smell and hope that you can smell it? “One might equally hope to color the lake with a drop of carmine,” Fabre wrote on this occasion.
Fabre could not believe in such “supersensitivity” of insects, although, by the way, he himself proved it. And not only experiments with butterflies.
Fabre carried out experiments with burying beetles, in particular with black burying beetles. If you and I, when we are in the forest, do not come across animal corpses, then we know: this is the merit of insects. Moreover, you and I already know that insects are very important orderlies on our planet. Gravedigger beetles (there are more than 20 species of them in the USSR, and black ones are the largest) are one of the most active orderlies. As soon as a dead bird or animal appears in the forest, gravediggers will soon appear. Every hour there are more and more of them, and the new arrivals immediately get to work - they begin to bury the corpse. They will bury it very quickly - in less than a few hours the corpse of a bird, or a mouse, or even a hare (a huge beast for beetles!) will be removed from the surface of the earth.
The beetles do this work, of course, not out of love for cleanliness and order. There, on the corpse, they laid their testicles, providing their future offspring with relative safety and an unlimited amount of food at first. This has been clear to people for a long time, and Fabre knew it. But something else was unclear in those days: where do insects appear near a dead bird or animal, and appear very quickly.
Well, let's say one beetle could happen to be nearby and accidentally come across a dead mouse or bird. Let's say the same thing happened to two or three more beetles. But several dozen could not have happened to be nearby. This means they came from afar; Perhaps they traveled hundreds, or even thousands of meters - the smell showed them the way. This has been clarified for sure. It has even been discovered how this smell spreads. Both Fabre and a number of scientists after him carried out many experiments to make sure that the smell spreads across the surface of the earth. Neither grass, nor stumps, nor trees prevent the beetles from smelling this smell. But if a dead animal is raised above the ground - such experiments have been carried out - and the smell, it would seem, can spread unhindered, the beetles do not perceive it. As soon as the corpse was lowered, the beetles received a “message” and hurried towards the smell.
Fabre's discovery did not go unnoticed, and it cannot be said that people have not studied the issue of insect smell. But work in this direction for many years proceeded very slowly, it was carried out by individual scientists, and it did not arouse much interest.
Even almost half a century later, in 1935, when the Soviet amateur entomologist A. Fabry (by a strange coincidence, almost the namesake of the famous Frenchman) published in the Entomological Review the results of his very interesting experiments and observations, which should have aroused great interest, the article remained almost unnoticed. Perhaps scientists then still could not understand and appreciate the role that smells play in the life of insects, perhaps humanity had already begun a chemical battle with six-legged animals and was entirely occupied with this, but, one way or another, most entomologists either did not notice the article Fabri, or remained indifferent to her. And the article was worth thinking about.
Fabry conducted an experiment with the same Saturnia butterfly, more precisely, with the pear Saturnia, or the large night peacock's eye, which so amazed Fabre. Near Poltava, where Fabry lived, these butterflies were not found, at least no one had found them there before Fabry. An amateur entomologist took this butterfly out of its pupa, placed it in a cage and took it out onto the balcony. He, of course, did not suspect what would happen - he simply took the newborn out to get some fresh air. And suddenly I saw exactly the same butterfly next to the fish tank. Fabry caught it - a rare butterfly! And after a few days, he already had dozens of male Saturnia pears who had flown in at the smell of the female. Where did they come from, where did they come from, what distance did they travel? Fabry decided to find out. And so, having marked the males with paint, he gave the butterflies to the youngsters who helped him. The guys took the butterflies to a distance of 6 kilometers from Fabri’s house and released them. The first tagged male returned after 40 minutes, the last - after an hour and a half.
But Fabre himself did an experiment with “forest orderlies” - gravediggers and carrion eaters and became convinced of how subtle the sense of smell is in insects
We increased the distance to 8 kilometers, the result was the same - almost all the males returned. And the most interesting thing is that they flew both when the wind was blowing towards them, and when there was no wind at all, and when the wind was blowing “at their backs.”
Fabry, like Fabre, could not explain this phenomenon. The explanation came much later, when scientists began to seriously study the sense of smell of insects. By that time, enough facts had already been accumulated - amazing and irrefutable; By that time, the “olfactory capabilities” of insects had been more accurately studied. For example, it was found that nun butterflies fly from a distance of 200-300 meters, one of the species of Saturnia - from 2.4 kilometers, the cabbage moth - from 3 kilometers, the gypsy moth is able to perceive the smell of a female at a distance of 3.8 kilometers, and the large night peacock eye (pear saturnia) from 8 kilometers. Not satisfied with this, scientists decided to “examine” the ocellated butterflies. Having been tagged, they began to be released from the window of a moving train. From a distance of 4.1 kilometers to the cage where the female was located, 40 percent of the males flew, and from a distance of 11 kilometers - 26 percent.
American scientists E. Wilson and W. Bossert even calculated the size and shape of the zone within which the smell that attracts butterflies operates. If the female is high above the ground, the scent zone has a spherical shape; if on the ground, it is hemispherical. If the wind blows, the zone extends in the direction of the wind. The size of such a zone for a gypsy moth in a moderate wind will be several thousand meters in length and approximately 200 meters in width.
You can imagine the concentration of odor in this zone if you consider that the gland that secretes the odorous liquid is a million times less than the weight of the butterfly itself. A droplet is even smaller. In short, one molecule per cubic meter of air is the concentration of the odorous substance detected by males. This is so incredible that it confuses many scientists - is it a smell? Maybe it’s something else, some kind of waves not yet understood by people that help insects navigate space so easily and accurately and find each other? However, for now these are the assumptions of individual scientists. The majority believes that to find each other, insects use smell, which they believe more than vision. For example, many experiments have been carried out confirming that males (or females, since in some insects the attractive odor is emitted by male individuals) fly to an object on which the corresponding odorous liquid is applied, and even if this object is completely different on an insect. And vice versa: the males did not pay any attention to the butterfly whose scent gland was removed.
The importance of an attractive smell is evidenced by the fact that this system is designed with amazing precision. For example, quite recently, scientists have established that some butterflies do not emit odor signals spontaneously, when necessary, but only when they are mature enough. Sometimes this happens a few hours after hatching, and sometimes after 2-3 days.
Others, on the contrary, are in a hurry and send odor signals even before they are born. The “grooms” fly in and patiently wait for the “bride” to emerge from the chrysalis.
There is an even more complex signaling principle: some butterflies send signals only at certain times. For example, some - only from 9 to 12 o'clock at night, others - from 4 o'clock in the morning until sunrise, and so on.
Smell serves insects not only to attract each other. It plays a decisive role in the choice of food for future offspring. For example, cabbage butterflies lay their eggs on cabbage to provide caterpillars with food. A signal indicating that this is exactly the plant that future caterpillars need is the smell. They believe him so much that if you moisten a sheet of paper or a fence board with cabbage juice, the butterfly will not pay attention to the shape or color of the object and will lay eggs on this board or sheet of paper.
Just as insects believe more in their “nose” than in their eyes, this is also evidenced by the following observations: certain types of orchids emit a smell similar to that emitted by the females of some bumblebees. Attracted by this smell, the males land on the flower. Having become convinced of the cunning of orchids, they fly away, but very often they fall for the bait again - they land on the flower again. The orchid “deceives” bumblebees in order to force them to transfer pollen. It is curious that these orchids do not have nectar - the scent bait completely replaces the delicacy bait.
Some flowers also act in the same “cunning” way, emitting the smell of rotting. It attracts flies that lay eggs on rotten meat. While the fly understands the deception, the flower will stick a portion of pollen to it. Having flown to another flower, the fly will transfer this pollen there.
Every year the leading biological significance of odors in the life of insects becomes clearer. Moreover, odors, it turns out, are strictly directed, strictly specialized. This forced scientists to start classifying them.
The Soviet scientist Professor Ya. D. Kirshenblat identified 12 types of odors according to their biological significance for animals.
But before we understand them, let's find out what smell is in general?
There is such a funny joke. During the exam, the professor asked a careless student: what is smell?
The student, who did not look at textbooks and did not attend lectures, did not know the material and, looking at the professor with innocent eyes, replied: “I forgot; I only knew it yesterday, but now it has slipped my mind out of excitement.” - “Madman!” exclaimed the professor. “Remember by all means! You are the only person in the world who knew what smell was!”
This is, of course, a joke. But seriously speaking, people still don’t really know exactly what smell is. That is, they know a lot, even too much - there are 30 theories of smell, but all of these are still theories, hypotheses.
One of the most common theories now is the “key” and “keyhole” theory.
Amazing and inscrutable are the ways of science! Almost two millennia ago, the Roman poet and philosopher Titus Livia Lucretius Carus expressed the original idea that for each specific smell, the olfactory organ of an animal has its own specific holes where these smells fall. How Lucretius came to such an idea is difficult to say. But after many centuries, armed with many facts, the finest equipment, and vast experience, scientists returned to the thoughts expressed by Lucretius. Of course, now scientists, unlike the Romans, know what an atom is, what cells are, what molecules are. But the principle of today's "key" and "keyhole" theory is very similar to the one Lucretius spoke about. It consists in the fact that the olfactory organs have holes of various shapes. And the molecules of the odorous substance have the same shape. The American scientist Eimour determined, for example, that the molecules of all odorous substances with the smell of camphor are spherical in shape, and the molecules of substances with a musky odor are disk-shaped. The holes have exactly the same shape. And when the molecule fits exactly into the appropriate hole, the animal smells the corresponding smell. The molecule will not enter the “foreign” hole, and the smell will not be felt, just as the key will not enter the “foreign” hole of the lock and the lock will not work - it will not open or close.
The main odors are now known: camphor, ethereal, floral, pungent, putrid and minty. The shapes of the molecules and their corresponding holes are also known. For example, substances with a floral odor have a disk-shaped molecule with a tail, while the molecule of a substance with an etheric odor is thin and elongated.
The mechanism of action is also known: for example, a molecule of an ethereal odor (chemists know that there are large and small molecules) must completely fill a narrow long hole. Therefore, the smell of ether will be felt if one large or two small molecules fall into the corresponding “keyhole”. And the molecules of the floral scent must fit into a shaped “well” - there is room in it for both the head and the long, thin, tucked tail. If a molecule fits into two or three wells, then the substance makes up a composition of two or three corresponding odors.
All this applies to the most developed creature - man, and to creatures that are very primitive in their development - insects.
The sense of smell in humans is poorly developed compared to many other mammals. It is believed that the average person can perceive 6-8 thousand odors, with a maximum of 10 thousand. The dog distinguishes between two million. Why this is so will become clear if we consider that the area of the dog’s nasal cavity reaches 100 square centimeters and contains 220 million olfactory cells, while in humans there are no more than 6 million of them and they are located on an area equal to approximately 5 square centimeters. In terms of the number of olfactory cells and the area of their location, insects, of course, cannot keep up with humans - where can they get five square centimeters? After all, the olfactory cells of insects are located on the antennae, and even then they do not occupy all the antennae, but only a small part of them. And it is clear that insects have much fewer olfactory cells, or even none at all. For example, the dragonfly, which finds food only through vision, has no sensitive elements called sensilla. And in flies that feed on flowers and search for them using both smell and vision, there are no more than 2 thousand such elements. For carrion flies, the sense of smell is much more important. Therefore, they have more olfactory cells - 3.5-4 thousand. Gadflies already have up to 7 thousand sensilla, and worker bees have more than 12.
But if in terms of the number of sensitive cells insects are significantly inferior to humans, then in terms of “quality”, in their very sensitivity, humans cannot even compare with insects.
To smell, a person needs to receive at least eight molecules of an odorous substance per sensitive cell. Only then will these cells begin to send messages to the brain. But the brain will react to messages only when it receives them from at least forty cells. So, a person needs at least 320 molecules to smell. Insects, as we know, can be content with one molecule per cubic meter air. The female squeak mosquito, feeding on the blood of animals, captures the carbon dioxide exhaled by animals and the heat and humidity they emit at a distance of up to 3 kilometers. It is difficult to say how many molecules will “reach” it; in any case, scientists have not yet calculated it, but probably only a few. Insects do not have the luxury of reacting only to tens or hundreds of molecules of an odorous substance; if necessary, they must be content with a few.
Long before Fabre's discovery, people had repeated opportunities to verify that insects have the ability to attract their own kind. People have often seen large concentrations of insects - for example, dangerous pest a turtle bug - but, of course, it never occurred to them that it was their own smell that had gathered the bugs in one place.
It has long been noticed that bed bugs do not appear in apartments right away; first, single “scouts” appear, then there are a lot of bed bugs. Of course, once in suitable conditions, bedbugs multiply quickly, but they come even faster from other places, attracted by the smell of their relatives.
Cockroaches also attract their relatives by smell, and the ability of flies to “call” their own kind has even been called the “fly factor.” It is known that as soon as one or two flies appear in places where these insects find abundant food, a whole swarm of flies immediately appears. And only recently they discovered an amazing phenomenon: having tasted suitable food, a fly immediately releases an appropriate smell that attracts its relatives.
And, finally, a smell that attracts insects of the opposite sex. All these are attractive smells, there are many of them, and they are very different from each other. But since they all perform one function - they attract their own kind - scientists united them into a common group and called them attractors, or epagons, which translated from Greek means “to attract.”
It is difficult to overestimate the importance of attractive odors in the life of insects. Without these odors, it is very possible that many insects would have ceased to exist on earth long ago.
Let's figure it out. Without attractive odors, insects would not be able to find each other on considerable distances(keep in mind that they are short-sighted) could not find each other, especially in the forest, in the grass or in the dark. And without finding each other, they could not continue their family, and it would gradually fade away. This is the first thing.
As we now know, many insects strive to provide their future offspring with food. And they also very often find it by smell. (Just think of the cabbage butterfly or burying beetles.) Or a more complex example is ichneumon wasps that lay their eggs in the larvae of lumberjacks or horntails. Under no circumstances can the rider see his prey - it is deep in the tree. And the rider also discovers it only by smell.
If the offspring are not provided with food, they will die as soon as they are born. And eventually the whole species will disappear completely.
This is the second one.
But not only larvae without attractive odors - and adults - at least many - would find themselves in a critical situation: not being able to find food, they would die of starvation. And this would also lead to the extinction of the entire species.
This is the third.
However, no matter how important attractive odors are, insects could not do without them alone.
Here's just one example. You and I know that riders lay eggs in caterpillars. Larvae emerge from the testicles and live in the caterpillar and feed on its tissues. In some riders, one larva emerges from one testicle; in many, several dozen emerge from one testicle. But no matter how many larvae appear, they always have enough food. However, this can happen: several riders will lay their eggs in the same caterpillar. Then there will be many more larvae, there will not be enough food for everyone, and the larvae will die. But this never happens, because, having laid eggs in the caterpillar, the rider marks this caterpillar with his smell, as if posting a notice: “The place is occupied.” Scientists call such odorous traces, marks, “odmichnions”, from the Greek words “odmi” - “smell” and “ichnion” - “trace”.
For many insects, odmychnions play an important role, but the most great importance they have for social insects - ants, bees, termites.
Every person has probably seen ant paths, but, obviously, few people know that ants run along these paths thanks to the smell that marks these paths. But it's not just about the roads. Having found suitable food, the ant marks the path to it so that it itself does not get lost and so that its relatives find the way to this food. Some species of ants often use marks to indicate the size or size of their prey. Having learned about this, people were faced with many other mysteries. For example, why don’t ants always follow the same tracks? Or: how do they find their way to their own home, and not end up in someone else’s, following the odorous trail of a fellow man?
And then it turned out that ants distinguish the smells not only of their close relatives - ants of the same species, but can determine which anthill it is from - their own or someone else's. So there is no confusion.
Ants do not run constantly and in the same tracks. That is, they constantly run along their paths, but only because the odorous tracks on them are constantly renewed. If the ant does not repeat its odorous trail (for example, the prey found somewhere is eaten or transferred to an anthill), the smell soon disappears and will no longer mislead anyone.
The smell inherent to a certain species (some scientists even believe that it is specific to each anthill) serves not only as a pointer to the house, but also as a pass into this house. If suddenly a stranger decides to wander into the anthill, he will be recognized by the smell and driven away. Moreover, the smell is the only “document”, the only “identity card”: if you smear an ant with the smell of an ant of another species, it will immediately be expelled by its own brothers and will be allowed back only after the alien smell has evaporated. Moreover, the smell is not only a document about “registration”, it is a document in general about the right to exist. If a living ant is stained with the smell of a dead one and placed in an anthill, it will immediately be taken out and thrown “into the cemetery,” that is, to the place where ants take their dead brothers. And in vain the living ant will resist, in vain it will prove by all means available to it that it is alive - it will not help. Yes, the ants see that they are dragging not a corpse, but a living fellow, but this does not concern them - they believe in the smell most of all.
The glands that produce odichnions are usually located on the abdomen of ants, and the ants mark everything they need with the tip of the abdomen. Bumblebees also have similar glands, but they are located on the head, at the base of the jaws (mandibles). In search of a friend, the bumblebee makes regular flights and lightly nibbles leaves on trees or bushes, leaving odorous marks. Using these marks, the female bumblebee will navigate and find the male bumblebee.
The same principle is preserved among bumblebees and some species of bees when it is necessary to mark the path to a food source: scouts who have found a sufficient number of flowers, on the way back, nibble on plant leaves from time to time, as if placing wayfinding signs. Moreover, the closer to the target, the stronger the smell.
It was believed that honey bees did not need such markers. But the famous Russian zoologist N.V. Nasonov, back in 1883, discovered odorous glands in them, which later received the name Nasonov’s glands. For a long time, the biological significance of this gland was unclear, and when people learned about the dances of bees, with which they indicate to their relatives the direction to a food source and report the distance to it, the significance of the odorous gland became even less clear. Only recently was it possible to find out the significance of this gland.
Based on the information received from the dancing scout bee, the remaining bees choose a direction and fly along it until they begin to smell the flowers. But there are many honey plants whose smell is too weak and not perceived by bees. This is where, it turns out, the smell produced by Nasonov’s gland comes into play. The scout bee releases an odorous substance into the air, which, as it were, marks the place and which serves as a guide and indicator for the rest of the bees: there is food here.
Like ants, the smell serves as a guide for bees to the house (only ants leave it on the ground, and bees leave it in the air), and serves as a “pass” to the hive.
Ants, bees, and some species of wasps have another specific odor, characteristic only of social insects, an alarm signal - toribones (from the Greek word "teribane" - "alarm"). Why these odors are characteristic only of social insects is understandable: after all, solitary insects have no need to give signals, no one to call for help or warn of danger, and finally, they have nothing to protect - they, as a rule, have no home. Therefore, a person, for example, can catch any single insect with complete impunity. In extreme cases, he risks being stung or bitten.
It’s another matter if a person encroaches on a paper wasp nest, for example. And the point is not that he will be stung by one or two wasps. It is this one wasp that can “set” all the inhabitants of the nest on a person. Before stinging, the social wasp sprays the enemy with small droplets of an odorous “alarm substance.” This substance, mixed with poison, serves as a signal to other wasps. And the more of them there are, the stronger the alarm “sounds”, and it, in turn, is a signal of attack.
Aggression in bees is even more active. It is enough for one bee to stick its sting into the skin of an enemy, and dozens of others immediately pounce on him, each trying to stick its sting close to the place where the previous one stung.
The bee's sting has 12 barbs, pointed backwards. Having stuck it, say, into the skin of a person, a worker bee can no longer pull the sting back out. It comes off together with the stinging apparatus and the gland that produces toribons. In this case, the bee dies, but the poison continues to enter the body of the enemy for some time, and for some time it remains marked with toribon, which causes aggression of other bees.
The mechanism and principle of using thoribons in bees and social wasps is similar and quite the same type. Another thing is ants.
Ants release thoribons not only at the moment of attack; much more often it is a preliminary, inviting, mobilizing signal. Or a signal that could be translated as a cry “save yourself who can!”
Sensing danger, the ant secretes toribon, which quickly spreads around and takes the shape of a ball. Usually this ball is small - no more than 6 centimeters in diameter. It also does not last long - a few seconds. However, both the magnitude and time of spread of the smell are sufficient to orientate oneself. If the alarm is false, there will be no panic: only insects nearby will feel the smell of alarm and will not react to it. If the alarm is real, then other ants will begin to release odorous substances, the “ball” will begin to increase in size, the smell will penetrate into all corners of the anthill and mobilize its entire population.
Ants of different species behave differently when in danger: some, sensing an alarm signal, immediately rush into battle, others, such as harvester ants, bury themselves in the ground, others run away, capturing pupae and larvae, while leaf-cutter ants react The toribons are mixed: some run away, taking with them a precious burden, others - soldiers, with their jaws open, rush at the enemy, and the smell excites them so much that, even after driving the enemy away, they cannot calm down and begin to torment each other. Even if the alarm turns out to be false and there is no enemy, the Leafcutter soldiers tear each other apart.
From the examples given, the biological meaning of odors is obvious, and it is clear what a huge role they play in the life of insects. However, odors not only attract insects to each other or to food sources, not only serve as landmarks and marks, not only act as alarm signals, but also regulate behavior. It is not for nothing that substances that regulate behavior are called etophions: from the Greek “ethos” - “custom” and “fiein” - “to create”. Etofions seem to be less active than, for example, epagons, which force butterflies to fly many kilometers, or than tori-bons, which instantly mobilize the entire hive to fight the enemy. Nevertheless, many insects need them. Without these substances, insects will not display vital instincts and will not develop the line of behavior they need.
Worker ants are known to feed the larvae. But what makes them do this? It turns out that it is the larvae themselves, or rather, the odorous substance that they secrete. Worker ants, attracted by the smell, happily lick etophions from the cover of the larvae, and this causes a feeding reaction. But something happened - the larvae stopped releasing odorous substances. We know that this will happen if the air becomes too dry or the room where the larvae are located is too bright. But the worker ants don't know this. However, the lack of discharge and odor will cause them to move the larvae to another location. And thereby save.
Even more curious is the relationship between larvae and adults in American nomadic ants. It is not for nothing that these ants are named so: their sedentary life unexpectedly ends, and they set off to wander. Ants wander for 18-19 days, moving, however, only at night, then again a long stay follows.
The reason for this unusual behavior of ants is the larvae. More precisely, the odorous substances that they emit. These odorous substances are licked by adult ants and cause them to move wherever they look. But on the 18th or 19th day the larvae pupate, and the ants immediately lose their desire to change places. Quite a lot of time passes, and the ants do not seem to be going on their way. On the contrary, events occur in their camp that are clearly not conducive to travel: the female lays eggs, and becomes more and more fertile every day. Then larvae emerge from the eggs, and suddenly one fine night the ants pick up the larvae, and the whole “camp” sets off. This means that the larvae began to secrete etophion. The ants will move for 18 or 19 nights until the larvae stop secreting substances that stimulate transitions. Then settled life will begin for a while. And then everything will happen again.
Ethophions, which strongly influence behavior, are also present in locusts. Locust larvae, the so-called walking locusts, or locusts, live separately from their parents: they hatch from eggs, which the locust lays in the ground during its wanderings. But sooner or later the locusts meet their parents. And then the locusts begin to worry, their antennae, hind legs and parts of the mouthparts begin to vibrate quickly, the larvae themselves fuss, get nervous, and push each other. And suddenly the locust sheds its green skin, becomes black and red, and has wings. At that moment the locust became an adult locust, ready to immediately take off. And all this happened because of the odorous substance that adult males secrete and which has such a strong effect on locusts. So much so that they literally “grow up” before our eyes.
In everyday life, you can often hear the expression “the chemical language of animals.” This refers to the various signals that animals give each other with smells. In principle, of course, this is true: the smell of anxiety, the attractive smell, and various marks and traces - this is language, commands or orders, warnings, and so on. In a broad sense, all odors can be considered a "chemical language". But, scientists believe, there are also special smells for exchanging specific information. It has been noticed, for example, that when two ants meet, they often touch each other with their antennae or pat each other on the back with their antennae. After this, the behavior of one or both ants changes - for example, they change the direction in which they were previously walking. Scientists believe that the main role in changing the behavior of the insect in this case was played not by the touch of the antennae, but by the smell that the insect felt. But what kind of smell this is, what its nature and purpose are, is not yet clear. American scientist E. Wilson, who studies this type of information, believes that up to 10 different “information” odors are used to ensure coordinated actions within one ant family. But in fact, there are obviously much more of them. In bees, in any case, it has now been possible to detect more than three dozen chemical substances that they use to exchange information. But the study of this kind of “language” is just beginning.
But another significance of smells in the life of insects has been well studied. They serve to protect against enemies (the substances that produce these odors are called “aminones”, which in Greek means “to drive away”). Indeed, who would want to deal with, for example, the so-called forest bug? Because of unpleasant odor It’s unpleasant even to look at him, although he is quite beautiful. And that’s all the bug needs - it’s not for nothing that it diligently smears itself with its front legs with an odorous liquid secreted by the glands located on its chest.
Ground beetles, cockroaches, and many other insects or larvae emit an unpleasant odor when in danger. At the same time, they are, as a rule, brightly and catchily colored, so that enemies remember them more easily.
We can talk a lot more about odors, which play a huge role in the life of insects, about the numerous amazing devices of their apparatus and organs, thanks to which these odors are released or perceived. People have given and are giving a lot of effort to understand all this, to understand the meaning of smells in the life of six-legged animals, and how they use them, and how they perceive them.
But sometimes it is very, very difficult!
When scientists not only set out to find out what insects’ sense of smell is, but also, thanks to the development of technology, had the opportunity to carry out experiments in the laboratory, it was necessary to isolate in its pure form a substance that emits an attractive odor.
The German chemist Butenind, who was awarded the Nobel Prize for his work on identifying the biological significance of odors in the life of insects, decided to isolate substances that emit the smell necessary for insects. He began his work in 1938 and graduated in 1959. Over these 20 years, he collected 12 milligrams of the odorous substance, “selecting” it from 500 thousand female gypsy moths. The American scientist M. Jacobson was more fortunate: he also worked with the gypsy moth, also used half a million butterflies, but over 30 years of work he managed to collect 20 milligrams of the odorous substance!
It was even more difficult when it was necessary to isolate the odorous substances of cockroaches. To do this, ten thousand female cockroaches had to be kept in special vessels connected by tubes to refrigerators. The air from the vessels entered the refrigerator, settled there in the form of fog, and then, through very complex chemical manipulations, odorous substances were released from this fog.
Over nine months, 12 milligrams of this substance were obtained.
Less than one and a half milligrams of the odorous substance were extracted from more than 30 thousand female pine sawflies. We can give many more examples of the work that goes into even such experiments. But, probably, a legitimate question has already arisen: why is all this necessary?
Indeed, is the matter worth such work and, of course, considerable expenses?
Well, let's start with the fact that nothing can be neglected in science. And even more so with such an amazing and significant fact. Having barely begun studying the olfactory abilities of insects, scientists found practical applications for these abilities. Or rather, they found a new means of pest control.
Even Fabre, then Fabry showed that insects not only travel enormous distances, obeying the call-smell, but also gather in large quantities. Further research confirmed this and clarified many things. For example, observations carried out in the field have shown that one female pine sawfly can attract more than 11 thousand males. What if...
Of course, extracting attractive substances is a difficult and time-consuming task; this can only be done for science. And for practice, the chemists had their say. They managed to synthesize and artificially make substances that fully correspond to those secreted by insects. And now planes are scattering tiny pieces over the Japanese islands insulating material saturated with such a substance.
We, of course, cannot say exactly what happened to the fruit flies against which this action was taken. But we can imagine how confused they were, how they rushed from one piece of bait to another, not understanding what was happening. They preferred baits, since the smell emanating from them was more active than the smell emitted by living relatives.
Yes, we can only imagine how the insects behaved. But we know the result for sure: the number of flies on these islands after such an “attack” decreased by 99 percent.
This is one way to fight. There are others too. For example, traps in which odorous baits are placed. Not only experiments, but also practice have shown the positive aspects of this method. It saves people from the need to produce and scatter tons of chemicals, which, on the one hand, are dangerous for all living things, and on the other hand, cannot serve as a reliable remedy against pests, since, as we now know, insects become accustomed to poisons over time. And insects will never get used to smells.
In practice, it looks like this: in the northeastern United States, about 30 thousand such traps are hung annually. And every year several tens of millions of insects fall into them.
Chemists and biologists still have a lot of work to do in this direction. For example, attractive odors are known that act on several dozen species of insects. But so far, despite all efforts, it has been possible to artificially create odors that attract only 7 species.
While work is underway to create substances that attract insects of one sex to another, scientists are interested in creating “food” attractive substances and creating traps based on this principle. Experiments on attracting fruit flies into traps containing a substance with the smell of cloves, or wood borers into traps containing a substance that emits a resinous odor, have shown that this option for pest control is also quite real.
It is known how dangerous the larvae of cockchafers are. And how difficult it is to fight them - after all, they live in the ground. But recently it was found that a newborn larva (and it does not necessarily emerge from an egg near a future food source) finds its way to the roots of plants by the increased concentration of carbon dioxide released by the roots. And now a new method of combating these larvae has already been developed: carbon dioxide is injected into the ground in a certain place with a syringe. The larvae gather in this area and are easy to destroy.
And the Canadian biologist Wright proposed a simple and effective method fight against mosquitoes, based on their amazing odor sensitivity. He came up with a trap consisting of a bath of water and a burning candle. Mosquitoes, as we have already said, are attracted to moisture, heat and carbon dioxide. Moisture is heated water; heat and carbon dioxide are provided by a burning candle. Mosquitoes fly to this bait from afar. And here you can do whatever you want with them - poison them or mechanically destroy them.
The method proposed by Dr. Wright is ingenious, but practically not very applicable, at least on a large scale. Much more promising is another, also based on the subtle and specific sense of smell of mosquitoes. The blood that mosquitoes suck from warm-blooded animals is needed for the rapid maturation of eggs. And mosquitoes lay them in places that are pointed out to them by another specific smell. People learned that this is a smell characteristic of stagnant waters and swamps. And now there is hope that it will be possible to artificially create a substance that emits a similar smell. If this happens, the “mosquito problem” will be largely solved. In any case, it will be possible to regulate the number of mosquitoes, forcing them to lay eggs in places where these eggs can be easily destroyed.
We now know that adult locusts, by emitting a certain odor, promote rapid maturation, growth, and transformation into adult locust insects, that is, larvae. Is it possible, on the contrary, to slow down the development of individuals? American scientists Williams and Waller thought about this. And they found out: just as certain substances accelerate the development of insects, other substances can slow down their development and prevent them from growing up at all.
As you can see, work is being done in all directions. There are still many failures, mainly due to the fact that we do not know our six-legged neighbors on the planet well. For example, some traps set for insect pests and equipped with a smell that attracts these particular insects catch large numbers of bees. Why? It's not clear yet.
For a long time, American scientists have been looking for a way to combat one of the most formidable agricultural pests in the United States - the gypsy moth.
Relatively recently, American scientists began to lure males to certain places with the scent of a female. This made it possible, firstly, to find out how many pests were in a given area (males flew from an area with a radius of 4 kilometers), secondly, the arriving males could be easily destroyed, and thirdly, even if they were not destroyed, sometimes they led me astray and did not give me the opportunity to find the female.
However, the difficulty of such a struggle was that chemists could not create an artificially odorous substance from silkworms. It was necessary to specially raise a large number of butterflies, then dilute in alcohol the parts of their abdomen on which the odorous glands are located, and use this “infusion” to attract males. But just recently, chemists managed to make an artificial odorous liquid from gypsy moths. If it really fully corresponds to the natural one, this will open up enormous prospects in the fight against a dangerous pest.
Unfortunately, people have a sad experience: artificial attractants have already been created, which do not seem to differ from natural ones either in chemical or other indicators. But they could not compete with natural ones. And why is still unclear.
In the fight against insects, the method of repelling with repellents is also used. Actually, this is not a struggle in the full sense, since the insect is not destroyed, it is simply expelled from a certain place. But sometimes this can be very important.
At one time, the most famous and popular repellent was naphthalene, which was widely used to repel certain types of moths. It worked flawlessly, but suddenly its effectiveness decreased. However, of course, not suddenly - the insects gradually developed immunity to this smell. And now he scares them away much less. For non-specialists, this question is extremely clear: the moth is accustomed to mothballs. This is a serious problem for specialists. After all, repellents are used not only against moths.
Something similar happens to many bloodsuckers who get used to it; and quite quickly, to various repellents. But constantly creating new ones is very difficult. But this has to be done while entomologists are trying to understand what happens to insects that become accustomed to repellents, and how this “addiction” is genetically transmitted from generation to generation. In general, smells open another new and very interesting page in the history of relations between people and insects. For now this page is only ajar. But it is already clear what prospects the study of smells opens up. After all, it is very possible that with the help of odors, people will be able not only to fight harmful insects, but also generally control the behavior of six-legged animals!
Any activity of insects is associated with the continuous processing of sound, olfactory, visual, tactile and other information. Including spatial, geometric, quantitative.
An important feature of these miniature, but very complex creatures is their ability to accurately assess the situation using their own instruments. Among them are determinants of various physical fields that make it possible to predict earthquakes, volcanic eruptions, floods, and weather changes. There are internal biological clocks that keep time, and some kind of speedometers that allow you to control speed, and navigation devices.
The sense organs of insects are often associated with the head. But it turns out that only their eyes are the only organ that is similar to other animals. And the structures responsible for collecting information about the environment are located in insects in the most different parts bodies. They can determine the temperature of objects and taste food with their feet, detect the presence of light with their backs, hear with their knees, mustaches, tail appendages, body hairs, etc.
Their delicate sense of smell and taste allows them to find food. Various glands of insects secrete substances to attract brothers, sexual partners, scare away rivals and enemies, and a highly sensitive sense of smell can detect the smell of these substances even from several kilometers away.
Insects are endowed with excellent color vision and useful night vision devices. It is curious that during rest they cannot close their eyes and therefore sleep with their eyes open.
Let's get acquainted with the various analyzing systems of insects in more detail.
The entire complex visual system of insects helps them, like most animals, to receive basic information about the world around them. Vision is necessary for insects when searching for food in order to avoid predators, explore objects of interest or the environment, and interact with other individuals during reproductive and social behavior.
Diversity in the structure of the eyes. Their eyes are compound, simple or with additional eyes, as well as larval. The most complex are compound eyes, which consist of many ommatidia that form hexagonal facets on the surface of the eye.
At its core, an ommatidium is a tiny visual apparatus that has a miniature lens, a light-conducting system and light-sensitive elements. Each facet perceives only a small part, a fragment of an object, but together they provide a mosaic image of the entire object. Compounded eyes, characteristic of most adult insects, are located on the sides of the head.
In some insects, for example, in the hunting dragonfly, which quickly reacts to the movement of prey, the eyes occupy half of the head. Each of her eyes consists of 28 thousand facets.
It is the eyes that contribute to the quick reaction of a hunting insect, such as a praying mantis. This, by the way, the only insect, which is able to turn around and look behind itself. Large eyes provide the mantis with binocular vision and allow it to accurately calculate the distance to the object of its attention. This ability, combined with the rapid thrusting of its front legs towards prey, makes mantises excellent hunters.
And the beetles of the family of whirligigs, running on water, have eyes that allow them to simultaneously see prey both on the surface of the water and under water. Thanks to their visual analysis system, these little creatures are able to constantly make corrections to the refractive index of water.
Night-vision devices. To sense heat rays, humans have skin thermoreceptors that respond to radiation only from powerful sources, such as the Sun, a fire, or a hot stove. But he is deprived of the ability to perceive infrared radiation from living beings. Therefore, in order to determine the location of objects in the dark by their own or reflected thermal radiation, scientists created night vision devices. However, these devices are inferior in sensitivity to the natural “thermal locators” of some nocturnal insects, including cockroaches. They have special infrared vision - their own night vision devices.
Some moths also have unique infrared locators to search for “their” flowers that open in the dark. And in order to translate invisible heat rays into a visible image, a fluorescence effect is created in their eyes. To do this, infrared rays pass through the complex optical system of the eye and are focused on a specially prepared pigment. It fluoresces, and thus the infrared image turns into visible light. And then in the butterfly’s eyes visible images of flowers appear, which at night emit radiation in the infrared region of the spectrum.
Thus, these flowers have radiation transmitters, and moths have radiation receivers, and they are expediently “tuned” to each other.
Infrared radiation also plays an important role in bringing together moths of the opposite sex. It turns out that as a result of ongoing physiological processes, the body temperature of some butterfly species is significantly higher than the ambient temperature. And what’s most interesting is that it depends little on the ambient temperature. That is, with a decrease in external temperature, their intraorganismal processes intensify, just like in warm-blooded animals.
The warm body of the butterfly becomes a source of infrared rays. The flapping of the wings interrupts the flow of these rays at a certain frequency. It is assumed that by perceiving these certain rhythmic vibrations infrared radiation, the male distinguishes the female of his species from the females of other species.
How do most animals and humans hear? The ears, where sounds cause the eardrum to vibrate - strong or weak, slow or fast. Any changes in vibrations provide the body with information about the nature of the sound being heard.
How do insects hear?
Features of the “ears” of insects. In many cases, they also have peculiar “ears,” but in insects they are located in places unusual for us: on the mustache - like in male mosquitoes, ants, butterflies, on the tail appendages - like in the American cockroach, on the stomach - like in locusts.
Some insects do not have special hearing organs. But they are capable of perceiving various vibrations in the air, including sound vibrations and ultrasonic waves that are inaccessible to our ears. The sensitive organs of such insects are thin hairs or tiny sensitive rods.
They are located in large numbers on different parts of the body and are associated with nerve cells. Thus, in hairy caterpillars, the “ears” are hairs, and in naked caterpillars, the entire skin of the body is the “ears”.
The auditory system of insects allows them to selectively respond to relatively high-frequency vibrations - they perceive the slightest vibrations of the surface, air or water.
For example, buzzing insects produce sound waves by rapidly flapping their wings. Males perceive such vibrations in the air, for example the squeak of mosquitoes, with their sensitive organs located on the antennae. And thus they detect air waves that accompany the flight of other mosquitoes and respond adequately to the received sound information.
The hearing organ in grasshoppers is located on the shins of the front legs, the movement of which occurs along arched trajectories. The peculiar “ears” seem to take bearings, or scan, the space on both sides of his body. The analyzing system, having received signals, processes the incoming information and controls the actions of the insect, sending the necessary impulses to certain muscles. In some cases, the grasshopper is directed to the source of the sound with precise commands, while in others, under unfavorable circumstances for it, it flees.
Using precise acoustic equipment, entomologists have determined that the sensitivity of the hearing organs of grasshoppers and some of their relatives is unusually high. Thus, locusts and some species of grasshoppers can perceive sound waves with an amplitude less than the diameter of a hydrogen atom.
Cricket communication. The cricket is a wonderful tool for communicating with a friend. When creating a gentle trill, he rubs the sharp side of one elytra against the surface of the other. And for the perception of sound, the male and female have a particularly sensitive thin cuticular membrane, which plays the role of an eardrum.
The following experiment is indicative: a chirping male was placed in front of a microphone, and a female was placed in another room near a telephone. When the microphone was turned on, the female, hearing the species-typical chirping of the male, rushed to the source of the sound - the telephone.
Ultrasonic protection of butterflies. Insects are able to make sounds and perceive them in the ultrasonic range. Due to this, some grasshoppers, praying mantises, and butterflies save their lives.
Thus, moths are provided with a device that warns them of the appearance of bats that use ultrasonic waves for orientation and hunting. In the chest, for example, moth moths have special organs for acoustic analysis of such signals. They make it possible to detect ultrasonic pulses from hunting leatherfish at a distance of up to 30 meters.
As soon as the butterfly perceives a signal from the predator's locator, its protective behavioral actions are activated. Having sensed the ultrasonic impulses of a bat at a relatively large distance, the butterfly abruptly changes its flight direction, using a deceptive maneuver - as if diving down. At the same time, she begins to perform aerobatic maneuvers - spirals and “loops” to escape pursuit. And if the predator is less than 6 meters away, the butterfly folds its wings and falls to the ground. And the bat does not detect the motionless insect.
In addition, some species of butterflies have even more complex defensive reactions. Having detected the bat's signals, they themselves begin to emit ultrasonic pulses in the form of clicks. Moreover, these impulses have such an effect on the predator that it, as if frightened, flies away. What makes such animals, which are quite large compared to a butterfly, stop pursuing and flee from the battlefield?
There are only assumptions on this matter. Probably, ultrasonic clicks are special insect signals, similar to those sent by the bat itself. But only they are much stronger. Expecting to hear a faint reflected sound from his own signal, the pursuer suddenly hears a deafening roar - as if a supersonic plane is breaking the sound barrier. But why is the bat not deafened by its own powerful signals sent into space, but only by the clicks of the butterfly?
It turns out that the bat is well protected from its own cry-impulse of its locator. Otherwise, such a powerful impulse, which is 2 thousand times stronger than the received reflected sounds, could deafen the mouse. To prevent this from happening, her body produces and purposefully uses a special stirrup. And before sending an ultrasonic impulse, a special muscle pulls this stapes away from the window of the cochlea of the inner ear - and the vibrations are mechanically interrupted. Essentially, the stirrup also makes a click, but not a sound, but an anti-sound one. After the scream-signal, it immediately returns to its place so that the ear is again ready to receive the reflected signal.
It is difficult to imagine how fast the muscle responsible for turning off the mouse’s hearing can act at the moment of sending a cry-impulse. When chasing prey, this is 200-250 pulses per second!
At the same time, the butterfly’s “scare” system is designed in such a way that its clicking signals, dangerous for the bat, are heard exactly at the moment when the hunter turns on his ear to perceive his echo. This means that the moth sends signals that are initially perfectly matched to the predator’s locator, causing it to fly away in fear. To do this, the insect’s body is tuned to receive the pulse frequency of an approaching hunter and sends a response signal exactly in unison with it.
This relationship between moths and bats raises many questions among scientists.
Could insects themselves develop the ability to perceive ultrasonic signals from bats and instantly understand the danger they pose? Could butterflies gradually, through a process of selection and improvement, develop an ultrasonic device with ideally selected protective characteristics?
The perception of ultrasonic signals from bats is also not easy to understand. The fact is that they recognize their echo among millions of voices and other sounds. And no screaming signals from fellow tribesmen, no ultrasonic signals emitted using equipment interfere with the bats’ hunting. Only butterfly signals, even artificially reproduced ones, cause the mouse to fly away.
Highly sensitive proboscis of flies. Flies exhibit an amazing ability to sense the world around them, purposefully act according to the situation, move quickly, and deftly manipulate their limbs, for which these miniature creatures are endowed with all senses and living devices. Let's look at some examples of how they use them.
It is known that flies, like butterflies, evaluate the taste of food with their feet. But their proboscis also contains sensitive chemical analyzers. At its end there is a special spongy pad - a labellum. During a very delicate experiment, one of the sensitive hairs on it was included in electrical circuit and touched the sugar with it. The device recorded electrical activity, showing that nervous system the flies received a signal about its taste.
The fly's proboscis is automatically connected to the readings of the chemical receptors (chemoreceptors) of the legs. When a positive command from the leg analyzers appears, the proboscis extends and the fly begins to eat or drink.
During the research, a certain substance was applied to the insect's foot. By straightening the proboscis, they judged what substance and in what concentrations the fly caught. Thanks to the special sensitivity and lightning-fast reaction of the insect, such a chemical analysis lasts only a few seconds. Experiments have shown that the sensitivity of the receptors of the front legs is 95% of that of the proboscis. And in the second and third pairs of legs it is 34 and 3%, respectively. That is, the fly does not taste food with its hind legs.
Olfactory organs. Insects also have well-developed olfactory organs. For example, flies react to the presence of even very small concentrations of a substance. Their antennae are short, but have feathery appendages, and therefore a large surface for contact with chemicals. Thanks to such antennas, flies are able to fly from afar and quite quickly to a fresh heap of manure or garbage in order to fulfill their purpose as nature's orderly.
The sense of smell helps females find and lay eggs on a ready-made nutrient substrate, that is, in the environment that will later serve as food for the larvae.
One of the many examples of flies using their excellent sense of smell is the tahini beetle. She lays eggs in the soil, finding by smell areas inhabited by beetles. The newly hatched young larvae, also using their sense of smell, search for the beetle themselves.
Beetles are also endowed with antennae of the olfactory type. These antennas allow you not only to catch the smell of the substance and the direction of its propagation, but also to even sense the shape of the odorous object.
And the ladybug’s sense of smell helps to find colonies of aphids in order to leave clutches there. After all, aphids feed not only on themselves, but also on their larvae.
Not only adult beetles, but also their larvae are often endowed with an excellent sense of smell. Thus, the larvae of the cockchafer are able to move to the roots of plants (pine, wheat), guided by a slightly increased concentration of carbon dioxide. In the experiments, the larvae immediately went to a patch of soil where a small amount of a substance that produces carbon dioxide was introduced.
Some Hymenoptera are endowed with such a keen sense of smell that it is not inferior to the famous sense of the dog. Thus, female riders, running along a tree trunk or stump, vigorously move their antennae. They “sniff out” with them the larvae of the horntail or woodcutter beetle, located in the wood at a depth of two to two and a half centimeters from the surface.
Or, thanks to the unique sensitivity of the antennae, the tiny rider Helis, by just touching the cocoons of spiders, determines what is in them - either underdeveloped testicles, or inactive spiders that have already emerged from them, or the testicles of other riders of their species.
How Helis manages such an accurate analysis is not yet known. Most likely, he senses a very subtle specific smell. Although it is possible that when tapping with the antennae, the rider catches some kind of reflected sound.
Taste sensations. A person clearly identifies the smell and taste of a substance, but in insects the taste and olfactory sensations are often not separated. They act as a single chemical feeling (perception).
Insects that have a sense of taste have a preference for certain substances depending on the nutrition characteristic of a given species. At the same time, they are able to distinguish between sweet, salty, bitter and sour. To come into contact with the food consumed, taste organs can be located on various parts of the body of insects - on the antennae, proboscis and legs. With their help, insects receive basic chemical information about the environment.
Thus, depending on the species, butterflies, due to their taste sensations, have a preference for one or another food item. The chemoreceptive organs of butterflies are located on their paws and respond to various substances through touch. For example, in the urticaria butterfly they are located on the tarsi of the second pair of legs.
It has been experimentally established that if you take a butterfly by the wings and touch a surface moistened with sugar syrup with its paws, its proboscis will react to this, although it itself is not sensitive to sugar syrup.
With the help of a taste analyzer, butterflies can clearly distinguish between solutions of quinine, sucrose, and hydrochloric acid. Moreover, with their paws they can feel the concentration of sugar in water 2 thousand times less than that which gives us the sensation of a sweetish taste.
As already mentioned, all phenomena associated with the life of animals are subject to certain rhythms. Cycles of building molecules regularly go through, processes of excitation and inhibition take place in the brain, gastric juice is secreted, heartbeat, breathing, etc. are observed. All this happens according to the “clock” that all living organisms have. Experiments have shown that they stop only with sudden cooling to 0°C and below.
In one of the experimental laboratories studying the mechanisms of action of the biological clock, experimental animals, including insects, were cooled for 12 hours. This is the most the best way influence on the time passing in the cells of their body. At the same time, the clock stopped for a while, and then, after warming up the animals, it turned on again.
As a result of such exposure to cockroaches, the biological clock went wrong. The insects began to fall asleep while the control cockroaches were crawling for food. And when they fell asleep, the experimental subjects ran to eat. That is, the experimental cockroaches did everything the same as the others, only with a delay of half a day. After all, after keeping them in the refrigerator, the scientists “turned the clock” to 12 hours.
Next, a complex microsurgical operation was performed - the subpharyngeal ganglion (part of the cockroach's brain), which controls the speed of the living clock, was transplanted into a control cockroach. Now this cockroach has acquired two centers that control biological time. But the periods when various processes were turned on differed by 12 hours, so the cockroach was completely confused. He could not distinguish day from night: he would start eating and immediately fall asleep, but after a while another ganglion would wake him up. As a result, the cockroach died. This shows how incredibly complex and necessary time devices are for all living beings.
An interesting experience was with small laboratory flies, Drosophila. They emerge from the pupae in the pre-dawn hours, with the appearance of the first sunbeam. The Drosophila organism checks its development clock against sundial. If you place fruit flies in complete darkness, the clock that monitors their development becomes disturbed, and the flies begin to emerge from their pupae at any time of the day. But what is important is that a second flash of light is enough to synchronize this development again. You can reduce the flash of light even to half a thousandth of a second, but the synchronizing effect will still appear - the flies emerging from the pupae will occur simultaneously. Only a sharp cooling of insects to 0°C and below entails, as shown above, the stopping of the body’s living clock. However, as soon as you warm them up, the clock will start moving again and will lag behind exactly the same amount of time as it was stopped for.
As an example demonstrating the excellent capabilities of insects for purposeful movements, consider the behavior of a fly.
Notice how the fly scurries around on the table, touching all objects with its moving legs. So she found sugar and greedily sucks it with her proboscis. Consequently, a fly can sense and select the food it needs by touching its legs.
If you want to catch a restless creature, it will not be easy at all. You carefully bring your hand closer to the fly, it immediately stops its movements and seems to become alert. And at the last moment, as soon as you wave your hand to grab it, the fly quickly flies away. She saw you, received certain signals about your intention, about the danger threatening her, and escaped. But after a short time, the memory helps the insect to return. In a beautiful, well-directed flight, the fly lands exactly where it was driven from to continue feasting on sugar.
Before and after a meal, a neat fly will gracefully clean its head and wings with its legs. As you can see, this miniature animal exhibits the ability to sense the world around it, act purposefully in accordance with the situation, move quickly, and deftly manipulate its limbs. For this purpose, the fly is endowed with excellent living devices and surprisingly useful devices.
She can take off without a run, instantly stop her fast flight, hover in the air, fly upside down and even backwards. In a matter of seconds, she can demonstrate many complex aerobatic maneuvers, including a loop. In addition, flies are able to perform actions in the air that other insects can only do on the ground, such as cleaning their legs in flight.
The excellent structure of the organs of movement provided to the fly allows it to carry out fast run and easy movement on any surface, including smooth, steep and even on the ceiling.
The fly's leg ends in a pair of claws and a pad between them. Thanks to this device, it exhibits an amazing ability to walk on surfaces on which other insects cannot even simply stand. Moreover, with its claws it clings to the slightest irregularities on the plane, and pads covered with hollow hairs allow it to move along a mirror-smooth surface. Through these microscopic “hoses” an oily secretion is released from special glands. The surface tension forces it creates hold the fly on the glass.
How to roll the perfect ball? The ability of one of nature’s orderlies, the dung beetle, to make perfectly round balls from manure never ceases to amaze. At the same time, the scarab beetle, or sacred copra, prepares such balls exclusively for use as food. And he rolls balls of another strictly defined shape to lay eggs in them. Clearly coordinated actions allow the beetle to perform quite complex manipulations.
First, the beetle carefully selects the piece of dung necessary for the base of the ball, assessing its quality using its sensory system. Then he clears the lump of adhering sand and sits on it, clasping it with his hind and middle legs. Turning from side to side, the beetle selects the desired material and rolls the ball in its direction. If the weather is dry, hot, this insect works especially quickly, rolling up a ball in a matter of minutes while the dung is still wet.
When making a ball, all the beetle's movements are precise and streamlined, even if it is doing it for the first time. After all, the sequence of appropriate actions contains the hereditary program of the insect.
The ideal shape of the ball is given by the hind legs, the curvature of which is strictly observed during the construction of the beetle's body. In addition, his genetic memory retains in encoded form the ability to perform certain types of stereotypical actions, and when creating a ball, he clearly follows them. The beetle invariably finishes the job only when the surface and dimensions of the ball coincide with the curvature of the shins of its legs.
Having finished the work, the scarab deftly rolls the ball with its hind legs towards its hole, moving backwards. At the same time, with enviable patience, he overcomes thickets of plants and mounds of earth, pulls the ball out of hollows and grooves.
An experiment was set up to test the perseverance and intelligence of the dung beetle. The ball was pinned to the ground with a long needle. The beetle, after much torment and attempts to move it, began to dig. Having discovered the needle, the scarab tried in vain to lift the ball, acting as a lever with its back. The beetle did not think of using the pebble lying nearby for support. However, when the pebble was moved closer, the scarab immediately climbed onto it and removed its ball from the needle.
Sometimes dung beetles try to steal a food ball from a neighbor. In this case, the robber, together with the owner, can roll it to the right place and, while he begins to dig a hole, drag away the prey. And then, if he is not hungry, leave him, having first ridden him a little for your pleasure. However, scarabs often fight even when there is an abundance of dung, as if they were in danger of starvation.
Manipulations of talented pipe divers. To create a cozy “cigar” nest from young tree leaves, female tubeworm beetles perform very complex and varied actions. Their “tools of production” are the legs, jaws and scapula - the female’s elongated and widened head at the end. It is estimated that the process of rolling a “cigar” consists of thirty clearly and consistently carried out operations.
First, the female carefully selects a leaf. It should not be damaged, since it is not only building material, but also a supply of food for future offspring. To roll a poplar, walnut or birch leaf into a tube, the female first pierces its petiole in a certain place. She knows this technique from birth; it reduces the flow of juices into the leaf - and then the leaf quickly withers and becomes pliable for further manipulation.
On the withered leaf, the female makes markings with precise movements, determining the line of the upcoming cut. After all, a tube cutter cuts out a piece of a certain rather intricate shape from a sheet. The “drawing” of the pattern is also encoded in genetic memory insect.
The once German mathematician Gaines, amazed by the hereditary “talents” of a small bug, derived a mathematical formula for such cutting. The accuracy of the calculations that the insect is endowed with is still surprising.
After preliminary work, the bug, even a very young one, slowly but surely folds the leaf, smoothing its edges with a spatula. Thanks to this technological technique, sticky juice is released from the rollers on the leaf cloves. The bug, of course, doesn’t think about it. Squeezing glue to fasten the edges of a leaf in order to provide a reliable home for future offspring is predetermined by the program of its expedient behavior.
The work of creating a comfortable and safe nest for babies is quite painstaking. The female, working day and night, manages to roll only two leaves per day. She lays 3-4 eggs in each, thereby making her modest contribution to the continuation of the life of the entire species.
Purposeful actions of the larva. A classic example of innate sequence of actions is demonstrated by the antlion larva. Its feeding behavior is based on an ambush strategy and has a number of complex preparatory operations.
The larva, hatched from the egg, immediately crawls onto the ant path, attracted by the smell of formic acid. The larva inherited knowledge about this signal smell of its future prey. On the path, she carefully selects a dry sandy area to build a funnel-shaped hole-trap.
To begin with, a larva with an amazing geometric accuracy draws a circle in the sand, indicating the size of the hole. Then she starts digging with one of her front paws.
To throw sand outside the circle, the larva loads it onto its own flat head. Having done this, she moves back, gradually returning to her original position. Then he makes a new circle and digs the next groove. And so on until it reaches the bottom of the funnel.
This innate program even provides for changing the tired “working” leg before the start of each cycle. Therefore, the larva makes the next groove in the opposite direction.
The larva forcefully throws small pebbles along the way outside the funnel. The larva deftly lifts a large stone, often several times heavier than the insect itself, onto its back and pulls it up with slow, careful movements. And if the stone is round and constantly rolls back, she gives up the useless work and begins to build another hole.
When the trap is ready, the next important stage for the insect begins. The larva buries itself in the sand, exposing only its long jaws. When any small insect finds itself at the edge of the hole, the sand under its feet crumbles. This serves as a signal to the hunter. Using its head as a catapult, the larva knocks down an unwary insect, most often an ant, with surprisingly accurate shots of grains of sand. The prey rolls down towards the waiting “lion”.
In this behavioral complex, all the actions of the larva are ideally consistent and perfectly coordinated - one strictly follows the other. However, the young insect not only performs its stereotypical actions, but also adapts them to specific conditions associated with to varying degrees weediness and moisture content of sandy soil.
The most sensitive sense of smell is recorded in these insects, because the male senses the female 11 km away
Alternative descriptionsUnit of quantity of substance
Butterfly, pest of things
Insect, pest
German botanist (1805-1872)
Rafting of timber in bulk
. "Shoe-eater"
Butterfly in the closet
Butterfly in a fur coat
Butterfly from grandma's chest
Butterfly from the closet
Butterfly, harmful insect
A butterfly hibernating in a closet
Butterfly being applauded
A butterfly that loves fur coats
Butterfly "wardrobe attendant"
Butterfly "fur-eater"
Harmful butterfly
Wardrobe rodent
F. aphid (from small) tiny moth (butterfly), panicle; its caterpillar, which wears furs and woolen clothing, Tinca. There are fur moths, clothing moths, cheese moths, bread moths, and vegetable moths. Moths disappear from hops and camphor. Vegetable moth, aphid, moth, broom, with which the caterpillar eats honeycombs. The smallest fish, recently hatched, molga, molka, molyava, lyavka, malga, see small. Fresh smelt is also called moth; novg. the smallest snowball. Moths smolder clothes, and sadness smolders the heart (or a person). Stuff your nose with tobacco, you won't get moths in your head! There are calluses on my teeth, my nails are swollen, my hair has been eaten by moths. Molie, molie cf. collect mole. Molitsa old moletocha aphids, moths, worms, moths. Yadyakhu... molits, crushed and mixed with dumplings and straw, in hunger. Moletochina, moleedina, egg. -poison is a place in things, in clothes, pierced by moths; damage from moths. Mole, molar, related to moths. Moth grass, St. John's wort, steppe seven-leaf plant, knoflic, Verbascum Blattaria. Molly, moly, full of moths
Timber floated down the river, not tied into rafts
Fur lover
M. in music: minor or sad mode, soft consonance, opposite gender. dur, major. Molny, related to moths
Little butterfly
A small butterfly whose caterpillar is a pest of fur, wool, grains, and plants
small butterfly
Fur Fighter
Butterfly
The story of the Russian writer A. G. Adamov "Black..."
Eater of fur coats and blouses
Rafting of timber in bulk, individual logs
Big fan of wool products
Unit of measurement of quantity of substance
Insect is a pest; units amount of substance
Fur loving insect
Unit of measurement of quantity of substance
. "fur-eater"
The story of the Russian writer A. G. Adamov “Black...”
Poisoned by mothballs
Victim of mothballs
She eats fur coats
Play by Russian playwright N. Pogodin
Pest in the closet
Butterfly “wardrobe attendant”
Loves to eat fur coats
Butterfly "fur-eater"
Butterfly - wool gourmet
Butterfly - wool gourmet
