Where does the termite live? How is a termite mound arranged? Termites and man

Termites (lat. Isoptera) are a detachment of social insects, similar in morphology and physiology to representatives of cockroaches. These are the oldest, most primitive social insects, the fossil remains of which are found in the layers of the Triassic period. In the people they are also called "white ants".

There are 7 families of termites, uniting more than 2500 species. 7 species of these animals are distributed on the territory of the CIS, including 2 species in the North Caucasus. The habitat of termites is limited to the tropical zone, less often they are found in the subtropics.

Termites live in communities in nests, wood, or ground cover. characteristic feature some species is the construction of termite mounds - nests towering above the surface of the earth. In such termite mounds there can be from several hundred to several million individuals. Secretive lifestyle. Termite mounds are built in a variety of shapes and sizes, in some species living in the tropics, above-ground nests reach a height of 15 meters.

These are herbivorous insects. The basis of their diet is plant and animal remains, some types of mushrooms, but they can also eat other foods. Many types of termite pests spoil leather, paper, wood, and agricultural products.

In termite families, there is a pronounced diversity of individuals within one species. This is the so-called caste and sexual polymorphism. The division of all family members into three groups is characteristic: winged individuals that are able to reproduce sexually, as well as wingless sterile soldiers and workers. Caste differences are manifested not only by external signs, but also by the functions performed.

The founders of the colony are the royal couple. After the mating flight, the wings of the male and female break off. They perform only a reproductive function in the community. A mature queen with hypertrophied ovaries is capable of laying several thousand eggs per day. Because of this, her chest and egg-filled abdomen are ten times larger than those of any working individual, the muscles of the limbs atrophy, and the female loses the ability to move independently. The male fertilizer is also located in the queen's compartment. Its dimensions do not exceed those of working individuals. He periodically mates with the female throughout his life (sometimes up to several decades). Other reproductive individuals have two pairs of membranous wings for flying to new places and creating new colonies there. They are characterized by well-developed compound eyes.

Structure . The body length of worker termites is from 2 mm to 1.5 cm, soldiers - up to 2 cm. Worker termites have underdeveloped eyes on their heads, sometimes absent, filiform antennae. Mouth apparatus gnawing type. In the appearance of soldiers protecting the community from external enemies, a large head with strong jaws attracts attention. Therefore, they cannot feed on their own, and worker termites are forced to feed them. Also, working individuals perform such functions as building the nest itself and the gallery, obtaining food for the royal couple and larvae.

reproduction . The development of termites proceeds with incomplete metamorphosis. The larva hatched from the egg looks like an adult. After several links it turns into an imago. The winged reproductives disperse from the nest, then mate. After that, a nesting chamber is built, which is the basis of a young colony, where they lay their eggs. From new larvae workers again appear, later soldiers and winged insects. The cycle of development is repeated.

Meaning. A positive role in nature is played by termites that live in the soil. Along with ants and earthworms, they play an essential role in the circulation of soil structures. The role of termites in food chains is also important, as they serve as food for many predatory animals.

About 10% of termite species are pests in the human economy. Penetrating into houses, termites destroy paper, wood, as well as all household items containing cellulose. Sometimes this leads to disastrous consequences. In the countries of the tropical belt, precautions are taken to prevent the entry of these insects into the home.

General information

Like all social insects, termite individuals are clearly divided into three main groups: workers, individual soldiers and individuals capable of sexual reproduction. Worker termites have a soft white body, typically less than 10mm in length. The eyes are reduced or absent. In contrast, reproductives have a dark body and developed eyes, as well as two pairs of long triangular wings, which, however, are shed after the reproductive's only flight.

As a group, termites evolved from cockroaches during the Triassic period, on the basis of which some entomologists include termites in the order Cockroaches. cockroaches of the genus Cryptocercus, famous for their well-developed care for offspring for cockroaches, carry in the intestines microflora similar to that of termites, and among termites there is a primitive species Mastotermes darwiniensis, similar in characteristics to both cockroaches and other termites. It is not known exactly how termites came to social life, unique among insects with incomplete metamorphosis, but it is known that early termites were winged and had a similar appearance. The remains of termites are quite often found in amber of different periods.

The bodies of adult termites and their wings are painted in various colors from whitish-yellow to black. Soldiers' heads can be light yellow, orange, reddish brown, or black. Among the smallest termite soldiers, members of the species Atlantitermes snyderi (Nasutitermitinae) from Trinidad and Guyana (South America) with a total length of 2.5 mm, and among the largest are soldiers Zootermopsis laticeps (Termopsidae) from Arizona (USA) and Mexico with a length of 22 mm. The largest among the winged sexual individuals are females and males. African genus termites Macroterms, whose length together with wings reaches 45 mm, and among the smallest winged termites Serritermes serrifer (Serritermitidae) - 6 mm with wings. Winged individuals of some representatives Incisiterms and Glyptoterms (Kalotermitidae) and Apicotermitinae are less than 7 mm long with wings. The number of families varies, from several hundred termites ( Kalotermitidae) up to several million individuals ( Rhinotermitidae, Termitidae) . Weight of adult wingless termites Mastoterms reaches 52 mg.

Colony structure and behavior

Polymorphism among termites
A- Reigning King
B- Ruling Queen
C- Second Queen
D- Third Queen
E- Soldiers
F- Worker

Like all social insects, termites live in colonies, the number of mature individuals in which can reach from several hundred to several million and consisting of castes. A typical colony consists of larvae (nymphs), workers, soldiers, and reproductives. Termite construction - termite mound. Unlike ants, in the most evolutionarily advanced termite species, caste is determined genetically. In more primitive species, the caste of an individual depends on what other termites feed it during development and what pheromones they secrete.

reproductive individuals

Among the reproductive individuals in the nest, a king and a queen are distinguished. These are individuals that have already lost their wings and, sometimes, their eyes and perform a reproductive function in the nest. A mature queen can lay several thousand eggs a day, turning into a kind of "egg factory". In this state, her chest and especially her abdomen increase, making the queen several dozen times larger than any worker (10 cm or more). Because of the queen's gigantic abdomen, she is no longer able to move on her own, so when it becomes necessary to move her to another cell in the colony, hundreds of workers join together to move her. On the surface of the queen's body, special pheromones are secreted, licked by workers, which contribute to the unification of the colony. In some species, these pheromones are so attractive to workers that they bite into the queen's abdomen with their mandibles (however, this rarely leads to her death).

The queen's chamber houses the king, which is only slightly larger than the worker termite. He continues to mate with the female throughout his life, unlike, for example, ants, in which the males die immediately after mating, and the sperm is stored inside the queen (womb) in the ovarian appendages.

Winged termites

The remaining reproductive individuals have wings and serve to create new colonies. At a certain time of the year, they fly out of the nest and mate in the air, after which the male and female, having descended to the ground, bite off their wings and together establish a new colony. In some termite species, immature reproductives form a podcast designed to replace the king and queen if they die. However, this happens extremely rarely.

workers

Unlike ants, termite workers and soldiers are equally divided between males and females. Worker termites are engaged in foraging, food storage, care for offspring, building and repairing the colony. Workers are the only caste capable of digesting cellulose, thanks to special intestinal symbiont microorganisms. It is they who feed all the other termites. Colonies also owe their impressive characteristics to workers.

Termite colony (termitary)

termite mound

The walls of the colony are built from a combination of excrement, shredded wood, and saliva. Some species create structures so strong that even machines break when trying to destroy them. The sizes of colonies of some African termite mounds are such that elephants hide in their shadow. The nest provides places for growing fungal gardens, keeping eggs and young larvae, reproductive individuals, as well as an extensive network of ventilation tunnels that allow maintaining an almost constant microclimate inside the termite mound. In addition, sometimes there are also rooms for termitophiles - animals that coexist with termites in symbiosis.

soldiers

Role in ecology

Classification

Traditionally, 7 families of termites were distinguished. Then added Stolotermitidae, Stylotermitidae and Archeorhinotermitidae(Engel & Krishna, 2004). In 2009, two more families were identified: Cratomastotermitidae and Archotermopsidae(Engel, Grimaldi & Krishna, 2009) .

• Mastotermitidae

see also

Notes

1. Engel Michael S. Family-group names for termites (Isoptera), redux (English) // zookeys. - 2011. - T. 148. - S. 171–184.
2. Engel M., D. A. Grimaldi and K. Krishna. BioOne Online Journals - Termites (Isoptera): Their Phylogeny, Classification, and Rise to Ecological Dominance.
3. Inward, D., G. Beccaloni, and P. Eggleton. Death of an order: a comprehensive molecular phylogenetic study confirms that termites are eusocial cockroaches // Biology Letters. - 2007. - T. 3. - S. 331–335.
4. Rudolf H. Scheffrahn. Termites (Isoptera) / Ed. John L. Capinera. - Encyclopedia of Entomology. - Springer Netherlands, 2008. - T. 20. - S. 3737-3747. - ISBN 978-1-4020-6242-1
5. Christine A. Nalepa. 2011. Body Size and Termite Evolution - Evolutionary Biology. Volume 38, Number 3 (2011), 243-257.
6. Robert G. Foottit, Peter H. Adler. Insect Biodiversity: science and society. - Blackwell Publishing Ltd, 2009. - S. 31. - 642 p. - ISBN 978-1-4051-5142-9
7. In Uzbekistan, more than 25,000 residential buildings are infected with termites. REGNUM (April 25, 2009). Archived from the original on August 22, 2011. Retrieved August 14, 2010.
8. Elements Science News: Termite Caste Is Genetically Predetermined
9. Kenji Matsuura. Sexual and Asexual Reproduction in Termites / Ed. David Edward Bignell, Yves Roisin, Nathan Lo. - Biology of Termites: a Modern Synthesis. - Springer Netherlands, 2011. - S. 255-277. - ISBN 978-90-481-3976-7
10. Silvia Bergamaschi, Tracy Z. Dawes-Gromadzki, Valerio Scali, Mario Marini and Barbara Mantovani. 2007. Karyology, mitochondrial DNA and the phylogeny of Australian termites. - Chromosome Research. Volume 15, Number 6 (2007), 735-753.
11. Corinne Rouland-Lefevre. Termites as Pests of Agriculture / Ed. David Edward Bignell, Yves Roisin, Nathan Lo. - Biology of Termites: a Modern Synthesis. - Springer Netherlands, 2011. - P. 499-517. - ISBN 978-90-481-3976-7
12. Ye Weimin et al. (2004). Phylogenetic relationships of nearctic Reticulitermes species (Isoptera: Rhinotermitidae) with particular reference to Reticulitermes arenincola Goellner. - Molecular Phylogenetics and Evolution. - 30(2004): 815–822.
13. Theodore A. Evans. Invasive Termites / Ed. David Edward Bignell, Yves Roisin, Nathan Lo. - Biology of Termites: a Modern Synthesis. - 2011. - S. 519-562. - ISBN 978-90-481-3976-7
14. Michael, Engel; David A. Grimaldi and Kumar Krishna. . BioOne Online Journals - Termites (Isoptera): Their Phylogeny, Classification, and Rise to Ecological Dominance . American Museum Novitates 3432:1-9.

Literature

• Zhuzhikov D.P. Features of the structure and regulation of development in the termite family. Readings in memory of N. A. Kholodkovsky: Dokl. for 38 years. reading, April 4, 1985 - L .: Nauka, 1986. - S. 74-105.
• Abe, T. D. E. Bignell, M. Higashi, eds. . Termites: Evolution, Sociality, Symbiosis, Ecology.- Kluwer Academic Publishing, Dordrecht.
• Donovan, S. E., D. T. Jones, W. A. ​​Sands and P. Eggleton. . The morphological phylogenetics of termites (Isoptera). - Biological Journal of the Linnean Society 70:467-513.
• Engel Michael, David A. Grimaldi and Kumar Krishna. . Termites (Isoptera): Their Phylogeny, Classification, and Rise to Ecological Dominance. American Museum Novitates. 3650:1-27.
• Engel, M. and K. Krishna. . Family-group names for termites (Isoptera). - American Museum Novitates 3432:1-9.
• Grasse, P.P. termitologia. Comporment, Sociatile, Ecologie, Evolution, Systematique.- Paris, Masson. - V.3, 715 p.

Links

• Termite wars could explain the evolution of social insects
• Termitology at www.isoptera.ufv.br (port.)

TERMITES
(Isoptera),
order of herbivorous insects. Although termites used to be called white ants, they are very far from real ants. These are the most primitive of social insects. Their highly developed social organization based on the various functions of the three main castes - producers, soldiers and workers. Most termites are found in the tropics, although they are also found in areas with temperate climate. Their main food is cellulose contained in wood, grass and tree leaves, so termites can cause economic damage by damaging wooden structures and woody species. The damage caused by them is significant in tropical and warm temperate areas, although it is also observed in southern Canada, central France, Korea and Japan.
Characteristics and castes. Termites differ from other insects in a combination of a number of features. Their metamorphosis is incomplete, i.e. an adult (imago) develops from a larva (nymph) after several molts. In other social insects, metamorphosis is complete - the larva, before becoming an adult, turns into a chrysalis. The wings, which are present only in reproductive individuals, are almost identical, long, with a seam at the base, along which they break off immediately after the dispersal summer. This is one of the unique features of males and females. Winged individuals have two compound (faceted) eyes, above which are two simple eyes, and short gnawing mandibles (mandibles). Soldiers by the features of their structure are adapted to protect the colony from predators. Its main enemies are ants. Soldiers usually have large heads with powerful gnawing mandibles, but in some species their mandibles are reduced and an outgrowth on the head serves as a weapon, from which the repellent secret of special glands (the so-called "nosed" soldiers) is sprayed onto the enemy. In one colony there may be two or even three types of soldiers, differing in protective devices. In soldiers and worker termites, the gonads, wings, and eyes are underdeveloped or absent altogether. These castes are non-functional males and females. Workers, found only in evolutionarily advanced termite species, are equipped with short, gnawing mandibles. In more primitive families, the functions of obtaining food and building a nest are performed by nymphs that look like workers. The name "white ants" refers to the coloration of termite workers, which is often light or even whitish. All termites outwardly differ from real ants in the absence of a narrow constriction separating the chest from the abdomen.

TERMITE CASTES. Immediately after swarming, winged reproductives shed their wings. Males and females form pairs, each of which becomes the ancestor of a new colony. If one of the producers (king or queen) in the colony dies, his "deputy" will develop from the nymph. Other adults belong to the worker and soldier castes. All individuals shown in the figure are typical of the genus Reticulitermes, except for the "nosed" soldier, who scares off enemies with a sticky secret sprayed from a ledge on his head.

Collier Encyclopedia. - Open society. 2000 .

See what "TERMITES" are in other dictionaries:

Termites ... Wikipedia

- (fr., from lat. termes). Insects of the order Orthoptera, commonly called white ants, live in tropical countries, making dwellings several feet high. Dictionary foreign words included in the Russian language. Chudinov A.N ... Dictionary of foreign words of the Russian language

Order of social insects. Communities, divided into castes, consist of winged and wingless individuals. They build underground and ground (up to 15 m high) nests (termite mounds). OK. 2600 species, mainly in the tropics; in Russia there are 2 species: one in the Sochi region ... Big Encyclopedic Dictionary

- (Isoptera), a detachment of insects. Close to cockroaches and mantises; naib, a primitive group among social insects. Winged individuals have 2 pairs of identical membranous wings, which break off after swarming and mating. Wingless individuals ... ... Biological encyclopedic Dictionary

- (Termitidae) a family of insects belonging to the Orthoptera order, to the Corrodentia group. The head of T. is large and free, the antennae are 13-23 segmented; compound eyes are round, ocelli 2; the mouthparts are highly developed and serve for ... ... Encyclopedia of Brockhaus and Efron

TERMITES- (Termitidae) social insects, belong to the termite order (Isoptera) with 1900 species. They are also called white ants, because, like these insects, they live in large societies and arrange large nests; besides, they have ... Insect life

Termites are small or medium-sized insects that usually avoid light and live in families in special termite nests. There are 3 main types of termite nests. Nests in wood - arranged quite simply and consist of a few, diffusely located chambers connected by passages. Nests fashioned from the ground come in various sizes - from small, inconspicuous mounds to huge, massive structures up to 3-5 m high, found in Africa. Nests made of cargon-like material - their termites build from carefully chewed wood, turned into paper pulp. The nest population is heterogeneous. Caste polymorphism is characteristic, which arose on the basis of incomplete transformation (there is no pupal stage), which extends not only to adults, but also to larval-like individuals. Termite castes are more varied and more pronounced than those of ants.

The order of termites is almost entirely tropical and subtropical, with only a few species living in the temperate zone. The northern and southern boundary of the termite range coincides with the annual +10° isotherm. The order includes about 2000 species, which are currently combined into 9 families. Within the territory of Soviet Union 4 families and 7 species of termites were known: 1) the family of dry wood termites (Kalotermitidae) is represented by the yellow-necked termite Kalotermes flavicollis Fabricius; 2) the family of reaper termites (Hodotermitidae) - the large Transcaspian termite Anacanthotermes ahngerianus Jacobson and the Turkestan termite Anacanthotermes turkestanicus Jacobson; 3) the family of woody termites (Rhinotermitidae) - the light-fearing termite Reticulitermes lucifugus Rossi and the Far Eastern termite Reticulitermes speratus Kolbe; a family of true, or higher termites (Termitidae) - the root-gnawing termite Amitermes rhizophagus Beljaeva and the Turkmen termite Microcerotermes turkmenicus Luppova.

The first three families belong to the so-called lower termites, the fourth - to the higher ones. Six species are termites living in natural biotopes of the European and Central Asian part former USSR, among which the most common in the territory Central Asia is the large Transcaspian termite Anacanthotermes ahngerianus. The seventh species, the Far Eastern termite Reticulitermes speratus, is an imported one, first discovered in Vladivostok in the 1960s, where it probably came with cargo from Korea, China or Japan. This is an inhabitant of wooden houses in the old districts of Vladivostok, and it has not been found outside the city. Some buildings, inhabited by the Far Eastern termite, fell into complete disrepair.

Termites within the USSR were distributed in Central Asia and in the south of Kazakhstan, in Ukraine, the Black Sea and Caspian coasts of the Caucasus. A small number of species of these insects in such a vast territory is explained by the fact that they are located here on the border of their range, in other words, at the northernmost border of their natural distribution.

Only three types of termites live on the territory of Russia: yellow-necked, photophobia and Far Eastern.

Comparative morphological analysis showed the similarity of termites with cockroaches. Especially a lot common features can be traced when comparing the families of relic cockroaches Cryptocercidae and mastotermitid termites Mastotermitidae. The bulk of fossil termites was found in Tertiary deposits and belongs to modern families.

In the process of development, termites go through several stages, each of which includes one or more instars; as a result of these changes, a certain caste appears with various morphological and physiological features.

Eggs commonly found in termite mounds in summer time, oblong-oval, whitish, laid singly, but in the chambers the nests are collected in heaps.

The larvae do not have external signs any caste. Their integuments are weakly sclerotized, usually white. This stage can have several ages and all castes pass through it.

Nymph - a stage that has the rudiments of wings; after several molts, the rudiments of wings increase in the nymph, and they turn into winged adults, but in the absence of a royal couple in the nest, they can develop into additional sexual individuals.

Imagoes in termites are winged individuals with gnawing mouthparts, filiform antennae, and well-developed compound eyes. The two pairs of wings are almost identical in shape and size and lack true cross-veins and cells. Only longitudinal veins are developed, and between them in lower termites there is a network of indistinct curved veins (archediction). Not far from the base, the wing crosses the shoulder suture, along which, after the departure of winged individuals from the nest, the wing plate breaks off; from the wings on the body of the termite, only the wing scale remains. Legs of walking type, almost identical on all thoracic segments. The tarsus of most termites is 4-segmented; in some primitive species, there is an arolium at the end of the tarsus, which in adults is reduced after shedding the wings.

The soldier caste are wingless, sterile individuals with a specialized head and mandible shape. The function of soldiers is to protect the nest, for this they have a massive, highly sclerotized head and mandibles of various structures, the shape of which depends on the method of protection. Soldiers cannot feed on their own and are fed by workers. In addition, the soldiers do not shed, and therefore do not have ages.

The largest caste is the workers. They perform many functions both inside and outside the nest. Workers collect food and deliver it to the nest, feed sexual individuals, soldiers, nymphs, larvae, guard eggs, build a nest, and get water. Workers are wingless individuals with underdeveloped genitals, like soldiers. Their body covers are weakly sclerotized and almost unpigmented, with the exception of the head. The eyes are absent or rudimentary. The head as a whole is similar to the head of an imago. Some lower termites do not have a real worker caste; it is replaced by pseudo-ergates, which perform all the functions of workers. In many species of termites, workers can transform into soldiers through an intermediate pro-soldier stage. Unlike soldiers, workers undergo a series of molts, while they do not change morphologically, but only increase in size.

Royal couple. Winged male and female give rise new family and it is they who are responsible for the resettlement of termites. Such a pair of founders is called the royal, or primary sexual individuals. They usually occupy a central place in the nest, and in higher termites, the royal couple is located in a special royal chamber. With age, the queen's abdomen greatly increases due to the extraordinary development of the ovaries and the strong stretching of the intersegmental membranes (physogaster). In this case, there is often a reduction in the eyes, skeletal muscles and some other organs. In many species in the Termitidae family, the queen is completely immobile. The belly of the king also increases, but much less, and he is always mobile.

Termites feed exclusively plant material: leaf litter, wood, herbivore droppings, dry grass, seeds, lichens, humus and very few species can damage living plants. Digestion of fiber is carried out with the help of flagellate protozoa and bacteria that live in the hindgut. Some representatives of higher termites arrange mushroom gardens in which they grow basidiomycetes, the mycelium of which insects feed on. Although termites feed exclusively on plant foods, they can also eat weakened individuals in their nest. Another feature in the diet of termites is the eating of humus contained in the soil, in the digestion of which spirochetes and free-living actinomycetes participate. Only working individuals independently obtain food and digest it, the rest of the population of the nest receives food from workers by burping through the mouth or with excrement.

Termites inhabit quite densely the forest soil of many tropical regions and, therefore, play a significant role in the processing of plant litter; making numerous moves in the soil, they mix it and influence the processes of soil formation. Termites are a favorite food for many animals, especially during their mass summer.

The positive role of termites in nature is undeniable. However, the economic damage from these insects is also great. An accurate calculation of the financial losses from termite activity has not been carried out in any country. They are believed to amount to about $1 billion a year. Termites are especially dangerous for wooden structures, to which they cause food damage. AT recent times It has been established that in the course of their construction activity, these insects actively damage also synthetic materials, for example, various cables, rubbers, plastics, etc. In this regard, important issue is to protect materials from damage by termites. Such work is constantly being carried out - new antiseptics are being developed that protect wood, new materials are being created that are resistant to termite damage. Huge amounts of money are spent annually on these activities.

Termites have long and constantly attracted the attention of both biologists, psychologists, sociologists, and amateurs who are interested in the mystery and unusual life of these insects. If biologists are interested in the morphology, biology and ecology of termites, their impact on the environment, then representatives of philosophical, psychological and sociological sciences are concerned about family structure, social relations in the termite family and between families, the role of the royal couple, especially the queen, in the regulation of all life activity. families. By studying the above features of the life of termites, these scientists are trying to transfer the principles of the structure of the family of these social insects to human society, take the organization of all life processes in termites as an ideal, and introduce these principles into human communities. But still, the main interest that attracts specialists to the study of termites is associated with their harmfulness and economic damage caused to the national economy.

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TERMITES(Isoptera), a group of herbivorous insects. Although termites used to be called white ants, they are very far from real ants. These are the most primitive of social insects. Their highly developed social organization is based on the various functions of the three main castes - producers, soldiers and workers. Most termites are found in the tropics, although they are also found in temperate regions. Their main food is cellulose, contained in wood, grass and tree leaves, so termites can cause economic damage by damaging wooden structures and woody species. The damage caused by them is significant in tropical and warm temperate areas, although it is also observed in southern Canada, central France, Korea and Japan.

Characteristics and castes.

Termites differ from other insects in a combination of a number of features. Their metamorphosis is incomplete, i.e. an adult (imago) develops from a larva (nymph) after several molts. In other social insects, metamorphosis is complete: the larva, before becoming an adult, turns into a pupa. The wings, which are present only in reproductive individuals, are almost identical, long, with a seam at the base, along which they break off immediately after the dispersal summer. This is one of the unique features of males and females. Winged individuals have two compound (faceted) eyes, above which are two simple eyes, and short gnawing mandibles (mandibles). Soldiers by the features of their structure are adapted to protect the colony from predators. Its main enemies are ants. Soldiers usually have large heads with powerful gnawing mandibles, but in some species their mandibles are reduced and an outgrowth on the head serves as a weapon, from which the repellent secret of special glands is sprayed onto the enemy (the so-called "nosed" soldiers). In one colony there may be two or even three types of soldiers, differing in protective devices. In soldiers and worker termites, the gonads, wings, and eyes are underdeveloped or absent altogether. These castes are non-functional males and females. Workers, found only in evolutionarily advanced termite species, are equipped with short, gnawing mandibles. In more primitive families, the functions of obtaining food and building a nest are performed by nymphs that look like workers. The name "white ants" refers to the coloration of termite workers, which is often light or even whitish. All termites outwardly differ from real ants in the absence of a narrow constriction separating the chest from the abdomen.

Foundation of the colony.

New colonies are founded by winged males and females. In the tropics, this usually occurs at the beginning of the rainy season. They swarm out of the parental nest through exits made by workers or nymphs. Having flown from several to several hundred meters, they land, shed their wings and form pairs. The female attracts the male with the volatile secretion of the abdominal gland, after which he follows her, they dig a hole together, seal the entrance into it and mate inside. A few days later, the first eggs are laid. Parents feed the nymphs hatching from them, and those, having molted several times, become workers or soldiers. Winged individuals will appear in the colony only when it "ripens", i.e. becomes densely populated, usually in two or three years. The formed workers take on all further care for the extraction of food and the construction of the nest.

Food.

The main food of almost all termites is cellulose or its derivatives. Usually termites eat dead branches and rotting parts of tree trunks, only occasionally attacking their living tissue, although some primitive tropical species have been reported to damage tea bushes and tree stems. Representatives of the subfamily Hodotermitinae damage forage crops in Africa and Asia. A number of species feed on cereals, collecting their dry shoots in the storage chambers of their underground nests or hill-shaped termite mounds. Some termites feed on dead leaves and quite a few on the humus of tropical soils. Representatives of the subfamily Macrotermitinae breed the so-called. mushroom gardens, populating their excrement or plant debris with mushroom mycelium, and then eating it.

Symbiotic protozoa.

In the hindgut of termites from four relatively primitive families (Mastotermitidae, Kalotermitidae, Hodotermitidae, and Rhinotermitidae), symbiotic flagellar protozoa (Protozoa) live. Their enzymes convert cellulose into soluble sugars, which are absorbed in the midgut of insects. About 500 species of protozoa are known to lead such a mutualistic way of life, and, apparently, they evolved in close relationship with their hosts, and both sides cannot exist without each other. The most progressive family of termites, Termitidae, which includes about three-quarters of all living species, does not have the simplest symbionts. The physiology of the digestion of cellulose and its derivatives by these insects is not yet fully understood.

nests

termites vary in complexity from simple burrows in a tree or soil to high structures (termite mounds) on the surface of the earth, pierced by a network of tunnels and chambers. Usually one - the royal - chamber is occupied by sexual individuals - the king and queen, and in several smaller ones there are eggs and developing nymphs. Sometimes food stores are arranged in some chambers, and in the nests of Macrotermitinae special large cavities are reserved for mushroom gardens. In the rainy tropics, termite mounds are sometimes crowned with umbrella-shaped roofs or, if they are on tree trunks, they are covered on top with specially constructed canopies that protect them from water. Underground nests of the genus Apicoterms in Africa, they are equipped with a complex ventilation system, the features of which can be used to judge the evolutionary relationships of the species of this group.

The shape of termite mounds reflects the behavioral characteristics of their creators. The nest is built by workers from earth, wood, their own saliva and excrement. The similarity of nests of different colonies of the same species is explained by the genetic commonality of reproductive individuals, i.e. the same innate instincts. No imitation and learning have been found in termites. The species-specific character of the nests is obvious in many cases, and in different species of the same genus one can notice general generic features of termite mounds. Thus, the cultivation of "mushroom gardens" is characteristic of all representatives of the whole subfamily, which unites 10 genera with 277 species, although in the course of the evolutionary divergence of these taxa, differences between their "gardens" also appeared.

Caste regulation.

Apparently, the number of individuals of different types is regulated in a certain way. The reproductive caste is necessary primarily for establishing new colonies and laying eggs. Usually, all individuals of a colony, in which there can be up to 3 million insects of different castes and stages of development, are the offspring of one king and one queen. Winged individuals of two sexes appear in a certain season for the dispersal summer. In primitive termites, the queens are relatively small, and their ovaries are only slightly enlarged compared to body size, but in more evolutionarily advanced taxa, the abdomen of the females that have begun breeding is huge and literally crammed with eggs. The length of queens of tropical species is 2-10 cm, and they lay up to 8000 eggs per day. In evolutionarily advanced species, the adult population consists mainly of workers, and only 1-15% of individuals become soldiers.

In experimental colonies, the removal of one or both reproductive individuals usually results in the development of their "deputies" from the nymphs - without wings or with only their rudiments. The removal of soldiers also stimulates the transformation into them of undifferentiated nymphs. The regulation of the caste composition of the colony is explained by the so-called. "theory of inhibition". It is assumed that reproductive individuals and soldiers secrete some kind of inhibitory substance (telergon), which is licked off by their relatives. The exchange of telergons between them (“mutual feeding”, or trophallaxis), which reaches the nymphs, suppresses the development of the latter into the corresponding castes. With the experimental removal of soldiers or spawners (or the aging of the royal couple), the number of telergons does not reach a threshold level, and the nymphs turn into those whose inhibitory substances are currently lacking.

Origin of social termites.

Termites evolved from ancient cockroaches, possibly at the end or beginning of the Paleozoic. modern cockroach Cryptocerus punctulatus, found in the Allegheny Mountains and in the states of Oregon and Washington, feeds on dead wood, contains symbiotic protozoa similar to those found in termites in the hindgut, and lives in family groups consisting of parents and young individuals at various stages of development. The species is thought to be similar to the supposed ancestors of termites. The most important step forward in their evolution was the inter-caste division of labor. Soldiers were the first specialized sterile caste, and adult sterile workers appeared in more advanced taxa. The oldest known remains of termites date from the Permian period, but their age is disputed. Representatives of evolutionarily advanced modern genera are already known among the Eocene fossils. For example, in the Eocene and Oligocene deposits of Europe and the Oligocene layers of the state of Colorado, winged individuals of the genus leading an underground lifestyle were found. Reticuliterms. This genus now unites most of the termites of the temperate zone of Eurasia and North America and belongs to the family Rhinotermitidae, which is only slightly more primitive than the youngest family Termitidae.

Judging by indirect data, namely by geographical distribution, many modern genera of termites arose in the Cretaceous period. If insects living in the soil are not found outside the tropics, but are present in Australia, Madagascar, the African continent, in Asia, as well as in Central and South America, there is only one explanation - they settled in different regions when they were parts of a single land or were very close to each other, i.e. no later than the Cretaceous period. Such an area is characteristic of some genera from the most evolutionarily advanced subfamilies.

In the nests of advanced termite taxa, especially those from the families Rhinotermitidae and Termitidae, about 500 species of termitophilous insects were found, i. as if "living". In the most specialized termitophiles, the abdomen is swollen, equipped with special glands. They secrete substances that are licked off by termite hosts, who in exchange feed them regurgitated food, care for their eggs and larvae, and in case of danger, they can even take some of their "guests" to a safe place. Termitophiles have appeared in several free-living groups of insects, including bed bugs (Aradidae), humpback flies (Phoridae), beetles from the lamellar beetles (Scarabaeidae), karapuziks (Histeridae), and short elytra or rove beetles (Staphylinidae). Indirect data indicate a long coevolution of termites and termitophiles.