Beetle ( Coleoptera )

What are beetles?
  1. The main distinguishing characteristic of the Coleoptera (sheath-winged) is the hardened forewings (elytra) six legs and antennae. In some cases the forewings are reduced
  2. "Sheath" refers to the elytra which forms a protective covering over the membranous hindwings and the relatively soft dorsal abdominal wall.
  3. All beetles have complete metamorphoses, i.e. egg-larva (several instars)-pupa- adult. It is that feature, complete metamorphosis, in combination with the elytra which characterizes insects of the order Coleoptera.
  4. In addition to providing food for amphibians, reptiles, fishes, birds and mammals, a role which they share with most other insects, beetles play other important roles in the environment. Many, cantharids, scarabs, byturids, and others, are pollinators). Dung beetles (scarabs, geotrupids, and others) feed on and reproduce in the dung of herbivores, thereby removing millions of tons of dung that would accumulate and destroy valuable pastureland and natural areas. Burying beetles (silphids) inter animal carcasses which are then used as food by the adults and their growing offspring thereby ridding the landscape of carcasses that would otherwise contaminate and foul the environment. Various nest-dwellers (including histerids, trogids, staphylinids) and fur ectoparasites (such as leiodids, leptinines) rid their bird and mammal hosts of parasitic insects, such as fleas, bed bugs, and lice. Some beetles are effective as biocontrol agents which predate plant-feeding insects. Among these are ladybug beetles (coccinellids) which feed on aphids and scale insects. The Vedalia ladybug beetle in California reduced the scourge of the cottony cushion scale (Icerya purchasi). Carabid beetles, such as the "caterpillar-hunters" (Calosoma, Carabus spp.) are often helpful in reducing populations of harmful caterpillars, such as gypsy moth and budworm caterpillars. Firefly larvae (glowworms) eat slugs and snails which damage such crops as tomatoes and lettuce.

by Dr. Lawrence Kaplan.

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Beetles or Coleoptera are one of approximately 30 orders of the class of Insecta. The Order of Coleoptera is in many respects sharply distinguished from other insects and is the favourite subject of study of both, professional scientists and naturalists.

The beetles are the largest order including more species known to science than any other order not only in the Class of Insecta, but also in the entire animal kingdom (Animalia). The most authoritative calculations indicate that already now more than 350,000 species of beetles have been described. Every year approximately 2000 new species are described (Zoological Record). Taking into account that the entire fauna of the earth is considered to include approximately 1,400,000 species it can be stated that beetles constitute more than a quarter of all known animals. Moreover, recent attempts of total collections of insects from several species of tropical trees in the basin of the Amazon River have shown that 50% of beetles found by this method are new (Erwin, 1982; 1997). Faunae from different species of trees are so very different from one another that it is possible to predict discovery of several hundreds of thousands or even millions of beetle species and according to some evaluations up to 7 million species.

Beetles are most abundant in the tropics; but at the same time they have got adapted to life at all latitudes and in nearly every habitat, to feeding on any substances of organic origin. Therefore, beetles are nearly ubiquitous. They have not been found on the Antarctic Continent yet, but inhabit the subantarctic islands, they have not been found in the open sea, but are abundant on sea coasts, they have not been found beyond the boundary of eternal snows, but very interesting species of beetles occur high in the mountains in the summer immediately close to this boundary. Many species of beetles attain large numbers. The above explains why the beetles are so well known. Beetles, as well as cats, dogs and birds are the first animals that a small child who begins to talk, learns to recognize.

Beetles are extremely diverse not only in size and colour, but also in body shape, sculpture of external cover, presence of various outgrowths, etc. Butterflies probably excel beetles in the splendour of colours, however, beetles have no match in the fantastic diversity of forms. Therefore beetles are an inexhaustible source of inspiration for writers, sculptors, artists, ornamenters and pattern-designers. Perhaps for this reason and also due to the extreme simplicity of storage of dead specimens beetles are a favourite object of collecting.

Many species of beetles are serious pests of agriculture and forestry, stored food, wood, leathers, furs, fabric. Other species, vice versa, are disturbed as a result of man's economic activity; they are permanently declining in numbers or become extinct. Some common species of beetles respond sensitively to the state of natural environment and may serve as convenient indicators of anthropogenic pollution. Therefore, knowledge of beetles is indispensable not only to professional zoologists, but also to plant protection specialists, agriculturists, arboriculturists, museum specialists and workers of food processing industry, ecologists, staff of reserves and specialists in many other areas.

All insects are studied by a special field of zoology - entomology. The study of beetles in its turn has long ago become a separate branch of entomology, coleopterology. Accordingly, specialists studying beetles are called coleopterists.

At the Zoological Institute of the Russian Academy of Sciences (hereinafter referred to as ZIN) coleopterology has long and famous traditions. Coleopterological study conducted at ZIN is based upon the Institute's collection containing now not less than 6 million of specimens. The collection was started as early as 1714 by Peter the Great when the Kunstkammer was established. A jump in the development of study of beetles is associated with to the name of E. Menetries, a world-famous entomologist . After him a series of prominent coleopterists including A.F. Moravitz, A.P. Semenov-Tian-Shansky, G.G. Jacobson, A.N. Reichardt, A.A. Richter, E.L. Gurjeva, M.E. Ter-Minasian, and O.L. Kryzhanovsky worked at ZIN.

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