Chemical signature and reproductive status in the facultatively polygynous ant Pachycondyla verenae.

In insects, cuticular hydrocarbons (CHCs) generally are used as cues and signals for within colony processes, such as signaling reproductive status, and between colony processes, such as colony membership. We examined CHC profiles of the facultatively polygynous ant Pachycondyla verenae in order to identify chemical signals of reproductive queens within colonies containing many gynes. Colonies of P. verenae, belonging to two different members of a complex of morphospecies, were collected from three geographic localities within South America. We also tested whether CHC profiles differed between geographic localities and morphospecies. We found three alkenes, two isomers of pentacosene and heptacosene, which were more abundant in CHC profiles of reproductive queens of this morphospecies complex. When we tested whether these differences were consistent across geographic localities, we found the abundance of these alkenes differed according to morphospecies, with the isomers of pentacosene being more abundant in queens from morph one, and heptacosene being more abundant in queens from morph two. Our study has given further insight into the mechanisms behind maintenance of reproductive dominance, and has demonstrated that chemical signatures associated with reproductive status in Pachycondyla verenae are not conserved within this species complex.