Caterpillar - anti -anthog

We all taught the fable “Dragonfly and Ant”, and some even sympathized with the Dragonfly: she died from cold and hunger, poor thing. But nothing, Narathura Japonica ’s butterflies took revenge on the dragonfly. Their larvae distinguish nutrients, having tried which ants are doomed to serve the caterpillars.

The Lycaenidae family has about 6,000 species, and most of them are to one degree or another associated with ants: adjacent to them, cooperates or parasitizes mutually beneficial. These ties can be both optional and bonding. Japanese scientists, professor at the University of Ryukeu Kazuki Tsuji and Dr. Mazaru Hojo, who is currently working at the University of Kobo, studied relations between the Darathura Japonica darling and the anti -anti -anti -anti [1] . N. japonica butterflies live in oak forests of Japan, Taiwan and Korea. They collaborate with several types of ants, and P. Punctatus is one of them. Ants act as bodyguards, for which they receive a reward: on the upper side of the caterpillar body there is a special exocrine gland, a dorsal nectary Organ), a bottom that distinguishes a vall mixture of sugars and amino acids. But ants are attracted to the caterpillars not the smell of nutrient drops, but the flying secret of unicellular glands covering the cuticle of caterpillars. Almost all pigeons have such pieces of iron; The molecules secreted by them protect insects from water loss, and each species smells in its own way. However, ants are very distinguished by the odorous secret of N. Japonica from the smell of caterpillars of other types of pigeons that are not inclined to cooperation. And they need to remember another fragrance. Next to the bottom of the caterpillars are tentacular organs (Tentacle Organs), then. This is a pair of twisting tentacles that secrete volatile substances calling ants if the caterpillar is in danger. In response to turning, the ants rush to defense. Of course, the cognitive abilities of the ants passed strict selection, as a result they are able to remember and distinguish many smells, without which the interaction with caterpillars would be impossible. However, the behavior of P. PUNCTATUS is regulated not only by smells: ants are not interested in the caterpillars N. Japonica and are in no hurry to protect them until they try the nutrient secret to the bottom.

This secret of ants seems to be fascinating: once having tasted it, they come to the tracks again and again or just stand around. Researchers suggested that the discharge of the bottom not only feed ants, but also somehow affect their behavior. Japanese researchers checked this hypothesis, together with an employee of the Museum of Comparative Zoology of Harvard University, Naomi Pierce, who has been studying the complex relations of a dovecite with ants for many years [2] .

Scientists worked with laboratory colonies of ants. 50 working individuals who never met caterpillars were placed in a plastic box called arena. In one arena, ants were expected by the caterpillar N. Japonica of the latest age, there was no caterpillar on another, and a caterpillar was planted in the third arena, in which the bottom was smeared with a small amount of nail polish. Previously, the researchers were convinced that the varnish, applied in small quantities to the body of the caterpillar, does not affect the behavior of insects. On all arenas there were a cotton wool impregnated with a 10%sugar solution for ants, young oak leaves for caterpillars and water.

After three days, scientists checked the action of the bottom on the locomotor activity of ants. To do this, 10 individuals from each arena were transplanted into Petri's cup with a diameter of 4.5 cm, the bottom of which was separated by the line. The ants were given to get comfortable in a new place, and then they calculated how many times in 15 minutes each insect crossed the dividing line. It turned out that the ants who tried the secret of the bottom are much less inclined to run in a cup than those who spent three days next to caterpillars without a bottom or at all did not meet with them.

The secret of the bottom not only suppresses the locomotor activity of ants, so that they are always next to the caterpillars, but also makes them reliable bodyguards. Researchers every three days transplanted 10 working ants from each arena into a Petri cup with a caterpillar, not hitherto not involved in experiments. The caterpillars are obviously uncomfortable, and they often turn out that. At the very beginning of the experiment, all ants ignored this action, but after three and six days the workers who managed to try the secret of the bottom, actively rushed to protect their wards, and ants of two other groups were still indifferent to the anxiety of caterpillars. These experiments once again confirmed that the protective behavior of P. PUNCTATUS is not innate, it causes a secret to the bottom.

The behavior of insects is determined by biogenic amines (serotonin, dopamine, octopamine and turramine), so the researchers suggested that the secret of the bottom affects P. punchtus behavior, changing the level of biogenic amines in the brain of workers' ants . It turned out that it really significantly reduces the level of dopamine. To make sure that it was dopamine that affects locomotor activity, the working individuals fed reserves, which suppresses the transport of dopamine to the synaptic gap. In other words, for ants fed by reserpine, dopamine does not work as a neurotransmitter. Resapine really significantly reduced the locomotor activity of ants.

Obviously, the secret of the bottom of the caterpillars affects the behavior of ants through the dopamineergic system. The level of sucrose affects the level of dopamine, and the bottom of the bottom in some types of pigeons contains sucrose. However, since all ants could receive sucrose from another source during the experiment in unlimited quantities, the secret of the bottom reduces the level of dopamine somehow differently; Perhaps it contains regulatory peptides.

Relations of the caterpillars N. Japonica and ants P. Punctatus were customary to describe as mutually beneficial: ants protect caterpillars in exchange for food. In fact, such relationships are not so beneficial to one of the parties: protection is vital to the caterpillars, but ants without caterpillars will not disappear, since they have other sources of food. Yes, caterpillars could not feed such a horde: it is too expensive for them, especially since the amount of nutritious secrets changes depending on the physiological state of insects and external conditions. There are many competitors for the attention of ants, there are many enemies, and there is only one caterpillar. How can she ensure the constant presence of a bodyguard? And N. Japonica found a way out. The secret of their bottom serves not only food for ants, this is a kind of drug that enhances the traction of ants for the caterpillars and the willingness to protect them. It is possible that the behavior of insects, which previously considered mutually beneficial, is actually the purest parasitism - the caterpillars simply manipulate ants.

Natalia Reznik

1. Hojo Mk, Yamamoto A., Akino T., Tsuji K., Yamaoka R. Ants Use Partner Specifc Odors to Learn to Recognize a Mutalistic Partner // Plos One. 2014. 9 (1): E86054. Doi: 10.1371/Journal.pone.0086054

2. Hojo Mk, Pierce Ne, Tsuji K. Lycaenid Caterpillar Secretions Manipulatt Attendant Ant Behavior // Current Biology. 2015 - http://dx.doi.org/10.1016/j.cub 2015.07.016