Among ants, recognition cues are mainly chemical. A cocktail of hydrocarbons provides a chemical signature, allowing workers to discriminate between kin and intruders. Many insects are strongly attracted by the valuable resources present in ant colonies, and myrmecophiles have several adaptive strategies to avoid or deter ant attacks. Myrmecophilous insects can break the recognition code of their host by being chemically insignificant or by using chemical mimicry or camouflage. The carabid subfamily Paussinae is among the largest myrmecophilous group, but the mechanism by which they have cracked the code of their hosts is still unknown. We investigated the chemical strategy adopted by Paussus favieri to live in host ant colonies of Pheidole pallidula. Our analyses show that the cuticular hydrocarbon profile of the beetle is a subset of the more complex profile of the ants, sharing more than 20 hydrocarbons. The relative proportions of the compounds in common are very different, and for this reason the PCA analysis shows that the chemical identities of beetles and ants are clearly distinct. However, P. pallidula are not aggressive towards P. favieri as suggested by the behavioral experiments; indeed, the beetles are continuously touched and actively licked, especially on the glandular antennae. In this ant-parasite system, we suggest that “chemical insignificance” and “camouflage” are unimportant, but the incomplete/imperfect chemical mimicry used by P. favieri is key to integrating into the ant colony, likely reinforced by the spreading of attractive antennal secretions.
Maurizi, E., D’Ettorre, P., DI GIULIO, A. (2013). Chemical strategy used by ant nest beetle Paussus favieri (Carabidae, Paussini). In XVIth European Carabidologists meeting. Abstract Book.
Chemical strategy used by ant nest beetle Paussus favieri (Carabidae, Paussini)
DI GIULIO, ANDREA
2013-01-01
Abstract
Among ants, recognition cues are mainly chemical. A cocktail of hydrocarbons provides a chemical signature, allowing workers to discriminate between kin and intruders. Many insects are strongly attracted by the valuable resources present in ant colonies, and myrmecophiles have several adaptive strategies to avoid or deter ant attacks. Myrmecophilous insects can break the recognition code of their host by being chemically insignificant or by using chemical mimicry or camouflage. The carabid subfamily Paussinae is among the largest myrmecophilous group, but the mechanism by which they have cracked the code of their hosts is still unknown. We investigated the chemical strategy adopted by Paussus favieri to live in host ant colonies of Pheidole pallidula. Our analyses show that the cuticular hydrocarbon profile of the beetle is a subset of the more complex profile of the ants, sharing more than 20 hydrocarbons. The relative proportions of the compounds in common are very different, and for this reason the PCA analysis shows that the chemical identities of beetles and ants are clearly distinct. However, P. pallidula are not aggressive towards P. favieri as suggested by the behavioral experiments; indeed, the beetles are continuously touched and actively licked, especially on the glandular antennae. In this ant-parasite system, we suggest that “chemical insignificance” and “camouflage” are unimportant, but the incomplete/imperfect chemical mimicry used by P. favieri is key to integrating into the ant colony, likely reinforced by the spreading of attractive antennal secretions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
