House-Infesting Ants of the Eastern United States (1965)

Classification and BionomicsAnts belong to the order Hymenoptera, which also includes the 'wasps and bees.The ants comprise the family B'ormicidae, and are distinguished from their nearest relatives by two important charac ters: Ona of these is the differentiation of the abdomen into two well marked regions-a slender, one-or two-segmented, freely moving ped icel, and a largel', more compact terminal portion, the gaster; the oth~r separating character is the elbowed antenna, in which the first seg ment, or scape, is greatly elongated in both the female and the worker.In the male, the antenna frequently does not appear to be elbowed, since the scape is not al ways noticeably lengthened .. Ants can be distinguished f!"om termites, with which they are com monly confused, by the strong constriction or "waist" between the thomx and the abdomen, and the two pairs of wings of which the an teriOl' pair is much larger than the posterior pair, ,both having few \'eins.Termites, on the other hand, have two pairs of wings, approxi mately eqtutl in size with numerous vains.They have a tendency to lose their wings more teadily than the ants.Termites also differ from the winged ants in that the abdomen is broadly joined to the thorax, There are normally three distinct castes of ants: Workers, females, and males.The male is generally winged, and retains its wings until death.Its size is usually intermediate between that of the worker and the female, and the male is characterized by its protruding genital appendages, the presence of ocelli, poorly developed or vestigial man dibles, and extraordinarily large eyes, which are out of proportion to the remainder of the head.Apparently, the sole flUlction of the maJa is to mate with the unfertilized female; when mating has been accom plished, the male perishes.Mating may take place in the nest, on the ground, or in the ILir.Ma.1e.c;; are produced in old or very large colonies only, where there is an abundance of food, since much nourishment is required to bring males to maturity.After attaining maturity, the ma.le usually does not rema,in long in the parental nest.After leav ing it, he may even succumb to predators ttnd the elements without having mated.The female, generally the largest of the three castes, normally pos sesses wings but loses thrun after mating.She usually possesses three ocelli in addition to the pair of large compound eyes, a large thorax to accommodate the two pail'S of wmgs, and a large abdomen for the production of numerous eggs.The primary Itmction of the femttle or queen is reproduction, but in many of the more highly specialized ants, the queen also cares fOl' and feeds the first brood of workers on her salivary secretions.She may live for many years; upon her death she is commonly replaced by a da,ughter queen.However, ants may have one or more queens, according to the species.The worker which is also a female, is never winged e.'{Cept as a rare abnormality.'The workers of most species lack ocelli.The thorax is simple, apparently composed of three segments, but in reality there are four.'" orkers are not always of the same size or morphologicnl structure in a O'iven species."Then workers are of approximately the same size l~nd structure within a species, we say the species is