Friday, February 22, 2008

Ants (1)

Ants are no doubt the most successful of all the social insects of the Hymenoptera, an order that also includes the social wasps and bees. Ants are colony makers and have inhabited the warmer environments of the earth for at least 100 million years. Their number are prodigious; it has been estimated that any one time there are at least one quadrillion (1x1015) living ants on the Earth, a number so large that it is almost meaningless. This individuals are members of some 5000 or perhaps as many as 10,000 species. Ants are remarkably adaptive and are found almost everywhere. In there feeding habits they range from species that specialize in feeding exclusively on Arthropod eggs to those which feed indiscriminately on any living or dead animal.

 

Form and Function

Ant colonies may contain from a few to upward of 20 million individuals. They consist of two or more castes and sub castes of females, and male are winged and appear only periodically in the life of the colony. The males are produced, as in all other Hymenoptera, from unfertillized eggs and serve only hand, develop from fertilized eggs and are the functional mainstay of the colony. Some are queens, usually winged; once inseminated, they produced large number of eggs from which the Larvae hatch. These immature ants are fed and cared for by the worker. In some species the worker vary in size, and subcastes are sometimes distinguishable. This is especially true for the largest worker, which are often referred to as soldiers. In such species a division of labor correlated with worker size may be evident. Small worker may, for instance, tend the larvae, while the larger worker forage for food.

 

The body of an ant is divided into three major parts; a head, with elbowed or geniculate Antenna and variable mandible; an alitrunk, or mesosoma, which the wings (when present) and legs are attached to the alitrunk by a one or two-segmented waist. In addition to the unique metapleural glands, the proventriculus, serve as a storage tank for liquid. This storage capability makes it possible for these ants to regurfitate food for larvae and for other adults.

 

When new males and queens emerge from a colony, they usually engage in a nuptial flight, during which fertilization occurs. The male dies soon after the flight, but the female drops to the ground, sheds her wings, and either is adopted by an existing colony or sequesters herself in a cavity, where she found a new colony.

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