Biology of ants
All ants are social insects that live in families. The number of individuals in an ant family can vary among different species from several tens to several million. Typically, an ant family consists of one or several fertile females and a large number of underdeveloped females - working individuals. The ants we usually see are working individuals who carry out all the functions of building and protecting the nest, caring for the young and oviparous females, and providing food for families.
If there is one fertile female in a family, such a family is called monogamous; if there are many, it is called polygamous. Most species have polygonal families - in red wood ants, for example, the number of fertile females reaches several hundred. However, some species kill the second oviparous female that appears in the nest.
Periodically, winged males and females appear in the nest. Females are similar to workers, but differ in their wide chest, which is associated with the development of flight muscles, and, as a rule, are larger in size.
Ants protect many plants from herbivores. At the same time, some of their species “look after” plant-feeding insects from the orders of Homoptera, transferring them from place to place, contributing to plant damage. The connections between animals and plants with ants are very complex. Ants often determine the composition of the fauna and flora of the places where they are found, and they are distributed throughout almost the entire forest area, and the ranges of individual species overlap each other, forming a kind of mosaic called an ant mosaic. Zoologists believe that the significance of the ant mosaic in many cases can serve as a justification for measures to protect individual forest areas. There are known cases where knowledge of the ant mosaic and its manipulation led to an increase in the yield of a number of plants.
Nests of ants of the genus Formica differ from ground nests of ants of other genera in a number of features: dome-shaped, large size, forest litter as a building material. They are counted using the route method: along the edges of forests, roads, neighborhood clearings, etc. Two or three routes more than 1 km long (usually 2-3 km) are laid. Along the routes, all spotted nests are counted, numbered, measured and sketched on the back of the registration form.
To describe the nests, it is enough to take and record linear measurements of the first 10 recorded anthills. Taking measurements of the anthill according to K.V. Arnoldi et al. (1979) Includes measurements of the diameter and height of the nest as a whole (D and H) and the dome of plant debris, without the earthen rampart (d and h), for a total of four measurements. If the dome of the anthill has an irregular or elongated shape, then the minimum and maximum diameter is fixed, preferably oriented to the cardinal points.
Ants are the largest family of insects in terms of number of individuals. And in terms of the number of species, few families can compete with it. Now there are approximately 6,000 species of ants, but given that more and more new species and genera are described every year and the fact that ants in many areas of the globe are almost unstudied, this number will be significantly increased. All ants have a characteristic feature by which they can be distinguished from any other Hymenoptera: between the thorax and abdomen they have a thin stalk of one or two segments, whereas in all other Hymenoptera the abdomen is directly attached to the thorax.
The reproduction and settlement of ants occurs as follows: once a year (twice in some species), for each species at its own time, many winged ants appear in the nest. These are young females and males. They still live in the nest for some time, and then begin to leave it. On warm autumn days, especially after rains, whole clouds of winged ants rise above the nests of some of our species. From a distance it seems as if light smoke is rising from the ground. A mass of swallows, swifts and other birds fly screaming in these swarms, grabbing ants. Fertilization occurs in the air or on the ground, after which the males soon die, and the females bite off their wings and begin to look for a place suitable for founding a nest. Here the female digs a small hole and lays the first portion of testicles, usually no more than a dozen. When the eggs hatch into larvae, she begins to feed them. But in most ants, the female never leaves the nest until the end of her life, and she feeds the larvae with secretions of the salivary glands. Fat reserves and unnecessary wing muscles are used for the formation of nutrients. Most of the eggs are also eaten, so that in the end 2-3 workers survive to adulthood. They are usually much smaller than normal. Now the female stops feeding the larvae and only lays eggs. Young workers take on all the work.
It’s simply hard to believe that the female of some species can live for about a year without eating, and not only live, but also care for the young, dig the ground and even feed the larvae. You can easily verify that this is indeed the case. At the beginning of autumn, a massive flight of the black garden ant occurs everywhere, the most numerous ant in the central zone of the European part of Russia. At this time, wingless fertilized young females run everywhere in large numbers in search of a place to build a nest. They can be found even in big cities on the sidewalks of crowded streets. If you catch such females, put each of them in a test tube with soil, cover it with cotton wool, and periodically moisten the soil, then by the end of winter the first tiny workers can be found in some test tubes. In nature, they appear by mid-summer, since development stops in winter.
In the life of an ant family, the period of independent existence of the female is the most dangerous. The vast majority of families die before they even begin to exist, precisely at this time. Therefore, a number of species have developed adaptations to avoid death. The easiest way is to divide old colonies, which is similar to swarming honey bees. This is how wandering ants and sometimes red flattering ants reproduce.
Temporary “social” parasitism is a widespread phenomenon among ants. Females of such species are usually much smaller than those of species that found their own nests. After the mating flight, they penetrate into the same formed nests of other species. Females of red forest ants establish new families in the nests of the brown forest ant and related species, which for some reason do not have their own female. Female hairy yellow ants penetrate the nests of black garden ants and kill the female. One way or another, the end result is a nest where the female is of one species and the workers are of another. The female lays eggs, and workers care for her and the young. Workers of the parasite species are gradually born and naturally replace workers of the host.
Ants, like most other Hymenoptera, feed on carbohydrate and protein foods. Carbohydrate food is “fuel” for the life of adult ants, and larvae and fertile females feed on protein food. In most cases, the source of protein food is various insects that workers hunt, but mushrooms or plant seeds can also be used. The workers eat part of the protein food themselves, since they feed the females with secretions of the salivary glands. The larvae are also fed with the same substances, but sometimes they feed on their own on pieces of insects that workers bring to them.
Although ants can feed on sugars on flowers, tree sap, etc., their main source of carbohydrate food is aphid excrement containing a large amount of sugar - honeydew. The symbiosis of ants with aphids, the study of which was initiated by the prominent Russian entomologist A.K. Mordvilko, apparently arose a very long time ago.
Most ants live in the ground. Their nests consist of a large number of chambers connected to each other by passages. There is often also a vertical passage with small chambers, going to great depths, sometimes several meters.
The economic importance of ants is extremely great. Many earth ants are useful soil builders, mixing, loosening and fertilizing the soil. Some species, such as red wood ants, tailor ants and some others, are used with great effect to control plant pests. Among the ants there are wood destroyers and agricultural pests, for example, harvester ants and leaf-cutter ants, etc. But the same harvester ants play a large positive role in natural pastures, as they carry the seeds of many plants and improve the soil. Some ants can carry diseases of humans and animals.
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