Biological observations on Pachyteles larvae (Coleoptera Carabidae Paussinae)

Larvae of Paussinae are poorly known. They are characterised by a hyperprog nathous head, a U-shaped body and the end of the abdomen (and the urogomphi ) transformed into a 6-lobed terminal disk. Most of them are myrmecophilous and live in ant nests; others, such as those of the genus Pachyteles Perty 1830, are non-parasitic and live in burrows in sandy banks or rotten Wood. on the basis of field and laboratory observations, we describe defensive a nd predatory behaviours of larvae of two species of Pachyteles, which use t heir terminal disk as both a phragmotic and trapping organ. These larvae at tract small invertebrates by secreting certain substances and catch their p rey by an ambush strategy. This is interpreted as a primitive predation str ategy in larvae of Paussinae. In the laboratory, we observed that ants and termites are strongly attracted by substances covering the terminal disk, T his behaviour could have played an important role in the origin of symphily , also suggesting the possibility of a multiple, independent evolution of m yrmecophily in pre-adapted Paussine tribes like Ozaenini, Protopaussini and Paussini.