As found in other species of grasshoppers, females of Chorthippus biguttulus respond to male courtship signals with their own acoustic signals. We take advantage of this behaviour by exposing females to different acoustic signals, male courtship signals or artificial signals, in order to investigate female preferences. Our aim is to determine the advantages of female choice and how variance in male signals and female preferences is maintained.

The bush cricket genus Poecilimon consists of roughly 120 species and occurs from Italy, over the Balkans and the Crimea into the Middle East. All members of the genus have reduced wings, which may explain the low mobility within the group and could be the cause for the high number of endemic taxa. However, local adaptations to different ecological parameters provide an additional explanation for the restricted gene flow between certain adjacent populations. In order to assess the role of ecotones in speciation processes, we intend to investigate the extent of genetic variation and gene flow along ecological gradients. Recent chorological and phenotype data for the genus Poecilimon suggests a prevailing parapatric mode of speciation in this taxon. We therefore regard Poecilimon as a suitable model system for studying speciation processes along ecological gradients. We are going to combine a phylogenetic and a population genetic approach to examine the extent of reproductive isolation between species and populations within this model system. Having inferred a robust phylogenetic hypothesis by applying multiple molecular makers, polymorphism in microsatellite markers within and among sister species will hopefully help tracing back recent speciation events.