@article{CastilloWurdackPaulietal.2022, author = {Castillo, Ruth and Wurdack, Mareike and Pauli, Thomas and Keller, Alexander and Feldhaar, Heike and Polidori, Carlo and Niehuis, Oliver and Schmitt, Thomas}, title = {Evidence for a chemical arms race between cuckoo wasps of the genus Hedychrum and their distantly related host apoid wasps}, series = {BMC Ecology and Evolution}, volume = {22}, journal = {BMC Ecology and Evolution}, number = {1}, doi = {10.1186/s12862-022-02093-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301289}, year = {2022}, abstract = {Background Brood parasites can exert strong selection pressure on their hosts. Many brood parasites escape their detection by mimicking sensory cues of their hosts. However, there is little evidence whether or not the hosts are able to escape the parasites' mimicry by changing these cues. We addressed this question by analyzing cuticular hydrocarbon (CHC) profiles of Cerceris and Philanthus wasps and their brood parasites, cuckoo wasps mimicking the CHC profiles of their hosts. Some of these hosts use hydrocarbons to preserve their prey against fungal infestation and thus, they cannot significantly change their CHC composition in response to chemical mimicry by Hedychrum brood parasites. Results We found that the CHC overlap between brood parasites and their hosts was lower in case of host wasps not preserving their prey than in case of prey-preserving host wasps, whose CHC evolution is constrained. Furthermore, the CHC profiles in non-preserving host wasps is more strongly diversified in females than in males, thus in the sex that is chemically mimicked by brood parasites. Conclusion Our results provide evidence for a chemical arms race between those hosts that are liberated from stabilizing selection on their chemical template and their parasites.}, language = {en} } @article{MaihoffBohlkeBrockmannetal.2022, author = {Maihoff, Fabienne and Bohlke, Kyte and Brockmann, Axel and Schmitt, Thomas}, title = {Increased complexity of worker CHC profiles in Apis dorsata correlates with nesting ecology}, series = {PLoS ONE}, volume = {17}, journal = {PLoS ONE}, number = {7}, doi = {10.1371/journal.pone.0271745}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301353}, year = {2022}, abstract = {Cuticular hydrocarbons (CHC) are known to serve as discrimination cues and will trigger defence behaviour in a plethora of eusocial insects. However, little is known how about nestmate recognition ability selects for CHC diversification. In this study we investigate differences in CHC composition of four major honey bee species with respect to the differences in their nesting behavior. In contrast to A. mellifera, A. cerana and A. florea, the giant honey bee A. dorsata prefers to build their nests in aggregations with very small spatial distances between nests, which increases the probability of intrusions. Thus, A. dorsata exhibits a particularly challenging nesting behavior which we hypothesize should be accompanied with an improved nestmate recognition system. Comparative analyses of the worker CHC profiles indicate that A. dorsata workers exhibit a unique and more complex CHC profile than the other three honey bee species. This increased complexity is likely based on a developmental process that retains the capability to synthesize methyl-branched hydrocarbons as adults. Furthermore, two sets of behavioral experiments provide evidence that A. dorsata shows an improved nestmate discrimination ability compared to the phylogenetically ancestral A. florea, which is also open-nesting but does not form nest aggregations. The results of our study suggest that ecological traits like nesting in aggregation might be able to drive CHC profile diversification even in closely related insect species.}, language = {en} }