Pachycondyla is a diverse group of 261 species and 61 species of stinging ponerine ants that are widespread in the world's tropics and subtropics. Most are general predators or scavengers, with some specializing in hunting termites. They nest on the ground, sometimes in the open, sometimes under rocks, logs or grass tufts.16 fossil species have also been identified (Wikipedia 2013; Bolton 2014).
Although officially a genus, Pachycondyla is a polyphyletic group, consisting of many subgenera with unclear relationships that will likely prove to be valid, distinct genera (Wikipedia 2013; TOL 2004).
Because they are similar in body shape, Pachycondyla workers are often confused with workers of species in the genera Cryptopone, Hypoponera and Ponera. Pachycondyla can be distinguished by the two spurs on the tip of the tibia on their hind legs: a larger serrated one and a smaller simple one. Species in the other genera have just the large spur (Shattuck 2000).
Two known Malayan Pachycondyla species are extraordinary in producing large quantities of defensive foam when threatened. These species have enlarged venom glands in their sting, in which they produce proteinaceous secretions.Scientists suggest that spiricles on the spiracular plate force air into the sting chamber to froth the secretions into a foam, which is then expelled in threads.These species also have a reduced Defore’s gland, so don’t produce the lipophilic hydrocarbons usually contributed by this organ to venom; when tested, these lipophilic hydrocarbons inhibited foaming of protein solutions, suggesting that in order to produce the foam, Defore’s gland must be deactivated. These ants do retain the ability to sting which is useful for prey capture and defense from large predators, but far less effective against small, fast, numerous invading arthropods (such as ants).Production of defensive foam, on the other hand, successfully fights off these smaller pests (Wikipedia 2013; Maschwitz et al. 1981).
