Ecological, behavioural and chemical adaptations to ant predation in species of Thermophilum andGraphipterus (Coleoptera: Carabidae) in the Sahara desert

Adaptations to arid environments in three North African ground beetles (Thermophilum sexmaculatum, T. venator, Graphipterus serrator) are described. The soil water content and food supply in ant nests are two obligatory requirements for reproduction of these beetle species during the hot and arid summer. The beetlesʹ larvae develop in nests of different ant species feeding on ants and/or their brood. Thermophilum larvae are able to find nests of their hosts by following the ant trails. They invade the nests through their entrances followed by attacking ants. A short period after starting to feed, Thermophilum larvae are able to move freely in the ant nests, which is explained by a chemical mimicry. A gas chromatographic analysis of T. sexmaculatum larvae shows that hydrocarbons of their prey appear in the carabid cuticula after feeding on ants. In contrast, larvae of G. serrator are never tolerated by ants. First instar larvae of G. serrator enter the entrances of the ant nests unnoticed, and live in a burrow near the brood chambers where they feed on the brood