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Postpetiole separated from the third abdominal segment by a constriction which is more or less marked (except in the Odontomachini and in certain males of Ponerini), almost always as broad as the third segment (except in Myrmecia HNS and a few others). Worker and female with a powerful sting. As a rule there is a stridulating organ on the basal surface of the tergite following the postpetiole; it consists of very fine transversal striae of the articulating surface. Median spur of the tibiae pectinate, when present, except on the middle tibiae of a few genera; lateral spur simple. Fore wing as a rule with two closed cubital cells; but there are many exceptions.
The dimorphism of the worker is feebly marked (except in Megaponera foetens HNS , where it is very pronounced) and the female as a rule is not very different from the worker; ergatoid females exist in many genera. In a few cases the male has no constriction behind the postpetiole; such males can usually be recognized from male Dolichoderinae by the feeble development of the mandibles. Ergatoid males are known for certain Ponerini.
larvae with the mandibles powerfully developed for ant larvae; the anterior portion of the body long, slender and neck-like, folded over the swollen abdominal portion; the segments are either densely hairy all over or covered with rows of peculiar tubercles beset with more or less prominent bristles; the larvae of Megaponera HNS and Bothroponera HNS are hairless.
Nymphs enclosed in a resistant cocoon, which may be opened by the adult without intervention of the worker. The West African Discothyrea oculata Emery HNS is the only case in which the nymphs are described as having no cocoon.
In the Ponerinae the larvae are nearly always fed with pieces of solid food, which is almost invariably animal matter. Arnold says that Euponera sennaarensis (Mayr) HNS is possibly an exception to the rule: This ant preys unceasingly on termites, but its nest very often contains considerable accumulations of grass seeds, which may perhaps be used as food.1
The economic value of the Ponerinae in tropical countries can hardly be overestimated, for it may be safely asserted that at least 80 per cent, of their food consists of termites, and they thereby constitute one of the chief checks to these pests of the tropics. Certain species are exceptional, such as Plectroctena mandibularis HNS , which feeds chiefly on millipedes and beetles, and Platythyrea arnoldi Forel HNS , whose food consists entirely of small beetles, mostly Tenebrionidae.
The colonies are usually small in ponerine ants, but may be very numerous in some species, such as Paltothyreus tarsatus HNS , Megaponera foetens HNS , Euponera sennaarensis HNS , many species of Leptogenys HNS and Odontomachus haematoda HNS .
The habit of foraging in files has been observed in several species of Ponerinae in different parts of the world. In our region this habit is displayed by Megaponera foetens HNS , and to a slight extent by Paltothyreus tarsatus HNS . The former marches in double file, and the striking disparity in size between the two forms composing the colony has a very singular appearance. Their prey consists entirely of termites, and when a suitable hunting-ground containing these animals has been found, the columns break up and pour into every hole and crack which leads to the invaded galleries. The method then adopted is as follows: each ant brings to the surface one or more termites, and then re-enters the galleries to bring up more victims. This is continued until each ant has retrieved about half a dozen termites, which, in a maimed condition, are left struggling feebly at the surface. The whole army reassembles again outside and each marauder picks up as many termites as it can conveniently carry, usually 3 or 4. The columns are then re-formed and march home. Less order is shown by P. tarsatus HNS , but I have often seen this ant carrying termites, in short single files composed of about a dozen workers. (G. Arnold, op. cit., pp. 7-8).