Song evolution and speciation in East-African bush-crickets (Orthoptera, Tettigonioidea)

• Applicant: Dr. Klaus-Gerhard Heller
• Subject Area: Sensory and Behavioural Biology
• Term: from 2006 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5437944

The process of speciation is often studied using morphological or genetic data only without exact information about the behaviour of the animals. In acoustically communicating animals, however, important parts of mating behaviour can be registered and analysed. This offers a unique possibility to measure and compare the speed of evolution in morphological as well as behavioural traits and estimate their importance for speciation. We will concentrate on two genera of East African bush-crickets (Insecta: Tettigioniidae: Phlesirtes, Aerotegmina) for which phylogenetic relationships and age of the species involved are currently under investigation (Wägele Wa 530/30). Since in Orthoptera the calling song pattern is one of the most important components of reproductive isolation, we expect to get a picture of evolution in progress of acoustic communication systems. The results will demonstrate if behaviour can be regarded as pace maker for speciation and if in this case intra- (e.g., sexual selection) or interspecific processes are more important. The isolation of the populations or species respectively extends from ice ages up to several million years ago. Both genera differ in ecology (Phlesirtes, conocephaline bush-crickets inhabiting grasslands; Aerotegmina, listroscelidine bush-crickets inhabiting the canopy), in song pattern and also in the history of dispersal.

• DFG Programme: Research Grants