Vibrational Communication Signals in Mantophasmatodea: Species Recognition, Sexual Selection, and Population Differentiation

• Applicant: Dr. Monika J.B. Eberhard
• Subject Area: Sensory and Behavioural Biology ; Evolution, Anthropology ; Systematics and Morphology (Zoology)
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 278477679

The use of substrate-borne vibrations to signal location, species identity, or sex, is considered a very ancient mode of communication and is extremely widespread within the animal kingdom. The long evolutionary history of this communication modality, the remarkable diversity of species in which it occurs, and its role in biotic interactions provide unparalleled opportunities to ask and answer various general questions concerning species recognition, signal evolution, sexual selection, and the role of communication signals in population differentiation and speciation. The importance of substrate vibrational communication for behavioural and evolutionary biology stands in high contrast to the little research conducted so far on only very few animal taxa. Only 13 years ago, the insect order Mantophasmatodea (heelwalkers) was discovered and since then, research has focussed mainly on taxonomy and phylogenetic reconstruction. However, the biology of heelwalkers including the role of the vibrational signals they produce has remained widely unexplored. Heelwalkers of both sexes tap their abdomen against the substrate (usually parts of plants) to create substrate vibrations. These vibrational calls probably serve for species identification and mate localization since they were shown to be species and sex specific. Mantophasmatodea therefore represent a perfect model system to investigate the evolution of percussive vibrational signals in a predatory insect for the first time and their role in population divergence. In the project proposed here, we will investigate the vibrational signals of species which occur in several populations at different localities in the Western Cape Region, a biodiversity hotspot. Behavioural experiments will be conducted to assess the decisive cues within vibrational communication calls which are used for species recognition. We will explore if character displacement takes place at sites where two or more species occur in sympatry. Female (and male) preferences will be investigated using playback experiments with artificial vibrational signals to reveal the influence of sexual selection on vibrational signal evolution. Field studies will allow for optimized seminatural laboratory setups. Finally, variability of vibrational calls, variability of somatic and genitalic morphological characters as well as genetic diversity using microsatellite markers will be investigated in populations of the same species to reveal the present state of population differentiation of Mantophasmatodea in the Western Cape. This will provide insight into the role vibrational communication might play for population differentiation and speciation in Mantophasmatodea.

• DFG Programme: Research Grants
• International Connection: South Africa
• Cooperation Partners: Professor Dr. Martin Haase; Dr. Klaus-Dieter Klass; Dr. Sven Künzel; Dr. Mike D. Picker; Professorin Dr. Gabriele Beate Uhl