Behavioural and Mechanical Isolation in the Great Grig, Cyphoderris monstrosa

Abstract

The Great Grig (Cyphoderris monstrosa) is a species that has shown evidence of possibly being in the early stages of speciation. This study uses mating trials to determine the degree of isolation between the Alberta and British Columbia populations behaviourally and looking at the morphology of the populations to determine the possibility of mechanical isolation in C. monstrosa, possibly representing pre-zygotic mating barriers. If C. monstrosa is in the early stages of speciation, then it is predicted that there will be distinct differences between the grigs, specifically behavioural differences seen when attempting to mate the two groups, and morphological differences in their genitalia. Analyses of behaviour and morphology showed that the two populations were significantly different in aspects of size and form of genitalia, with the Alberta grigs being larger than the British Columbia grigs. This finding is concurrent with other studies, indicating the possibility of speciation between the populations, as per the biological species concept. This study helps to answer questions regarding species concepts and speciation in the Great Grig, as well as indicates the need for future work with these insects.

Presented in absentia on April 27, 2020 at "Student Research Day" at MacEwan University in Edmonton, Alberta. (Conference cancelled)

Faculty Mentor: Kevin Judge

Department: Biological Sciences