Cuticular Hydrocarbons

All insects are covered with cuticular hydrocarbons which act as a desiccation barrier. There are several distinct molecule types in each species (chain lengths from C23 to C37, with differing positions of double bonds or methyl-branches). Different blends of cuticular hydrocarbons can reflect variations in age, reproductive physiology, as well as genotype (colony membership), among individuals. In social Hymenoptera, these cuticular differences encode information that underlie the resolution of reproductive conflicts as well as nestmate recognition ([[Media:Peeters GadauFewell HUP 2009.pdf|Peeters & Liebig 2009]]). More recently, cuticular hydrocarbons have been shown to be reliable markers of reproductive physiology in a number of species. The technique of solid-phase microextraction ([[Media:Monnin JCE 98 Dino.pdf|SPME]]) has been used successfully to sample hydrocarbons on the cuticle of live individuals. When combined with gas chromatography, this allows the temporal monitoring of individuals in experimentally disturbed colonies.

Long-chained hydrocarbons (HC) coating the exoskeleton are thus a chemical signature that is produced by a combination of genotype and physiology. This cuticular signature contains dual information about colony membership and fertility status, and it a challenge to identify which compounds are used for one or the other function. Colonies have a distinct odor that underlies nestmate recognition, i.e., the HC profile is perceived and assessed during initial encounters between individual ants, to discriminate friends or foes. According to the Gestalt model, all nestmates share a colonial odour as a result of homogenizing their HC profile through various means that include trophallaxis, allogrooming and passive transfer during nestmate contacts. Diet can also influence nestmate recognition in some species. However, as far as the various molecules that are correlated with fertility, there is no mixing. Future studies must investigate how intracolonial differences (fertility, but also age and sex) can be reconciled with a common colonial odour.

Cuticular hydrocarbon chemistry has been examined in many species belonging to all major subfamilies. This is often combined with studies of a wide variety of behaviors involved in nestmate and/or intracolonial recognition.


 * Camponotus floridanus
 * Diacamma ceylonense
 * Dinoponera quadriceps
 * Formica fusca
 * Gnamptogenys striatula
 * Harpegnathos saltator
 * Lasius niger
 * Linepithema humile
 * Myrmecia gulosa
 * Neoponera apicalis
 * Novomessor cockerelli
 * Streblognathus peetersi