TY - THES ID - 3452801 TI - Conflict and conflict resolution in insect societies. AU - Van Oystaeyen, Annette AU - Billen, Johan. AU - Wenseleers, Tom. AU - KU Leuven. Faculty of science. Department of biology. PY - 2014 SN - 9789086497010 PB - Leuven KU Leuven. Faculteit Wetenschappen DB - UniCat KW - 595.7 KW - Academic collection KW - Insecta (Hexapoda). Insects. Entomology KW - Theses KW - 595.7 Insecta (Hexapoda). Insects. Entomology UR - https://www.unicat.be/uniCat?func=search&query=sysid:3452801 AB - In insect societies, intracolonial conflict frequently arises because of conflicting genetic interests of non-clonal individuals. This conflict may be avoided by increasing genetic relatedness among colony members. This may be achieved through asexual or clonal reproduction by which conflicting genetic interests are silenced. An additional mechanism to resolve conflict over male production is policing, a mechanism whereby queens or workers aggress reproductive workers and/or cannibalize worker-laid eggs. To this end, workers need accurate cues that inform them on the presence of a fecund queen, because in queenless colonies, workers will cease policing and start reproducing. Queen caste-specific cuticular hydrocarbons can prevent worker ovary activation in different species belonging to groups of social insects that evolved eusociality idependently, i.e. the common wasp (Vespula vulgaris), a bumblebee (Bombus terrestris), and a Desert ant (Cataglyphis iberica). Interestingly, in all three species all identified queen pheromones are non-volatile linear and methyl-branched alkanes. In addition, comparative analysis and ancestral state reconstruction suggests that these queen pheromones evolved from conserved signals in solitary ancestors. Hence, hydrocarbons appear to have played a key role in the evolution of reproductive division of labour in social insects. This hypothesis is further strengthened by the finding that a methyl-branched alkane is used as a queen egg-marking pheromone in the common wasp. Together, these results demonstrate that saturated hydrocarbons present on the queen’s cuticle and eggs can fulfil the important role of queen pheromones. Intercolonial conflict arises when unrelated individuals infiltrate colonies to benefit nutritionally or reproductively from the host’s resources. In the case of brood parasitism, individuals forgo brood care and have their brood reared by their host. A special case of brood parasitism, queen reproductive parasitism, occurs in the stingless bee Melipona scutellaris. In this species, queen parasitism is common, with 1/3 of all take-overs being undertaken by alien queens. Furthermore, alien queens actively seek out queenless colonies, and employ a specific strategy to enter their target colonies. Lone queens enter colonies in the evening when guarding efficiency is significantly reduced, and thus maximize their chances on a successful take-over.Interspecific conflict occurs between members of different species. Parasites of social insect species might employ chemical mimicry to infiltrate colonies and avoid attack. A parasitic beetle, Metoecus paradoxus, uses different chemical strategies to enter colonies of his social insect host, the common wasp. The beetles do not acquire their host-specific cuticular hydrocarbon profile through contact with the host nest material, but appear to recycle hydrocarbons from their wasp host larvae. Furthermore, the beetle has significantly lower proportions of long-chain methyl-branched hydrocarbons on its cuticle when compared to his host. This type of compounds has been suggested to play a key role in nestmate recognition, and it might therefore indicate that chemical transparancy is used as a strategy to avoid detection. In addition, beetles overproduce common wasp queen pheromones, suggesting that queen mimicry is an important chemical strategy that the beetle uses to avoid attack by the workers in its host colony. ER -