Population Genomics of Tetraopes texanus (Coleoptera: Cerambycidae)

Specialist insects are especially susceptible to loss of genetic diversity in the face of habitat destruction and fragmentation. Implementing effective conservation practices for specialist insects will benefit from knowledge of population structure and genetic diversity. Due to the high diversity of insects, it is not feasible to gain inference as to the population structure of all species within the insect community, even when focusing on insects within a particular habitat type. Thus, identifying general trends by focusing on one or a few species specialized to a particular habitat type is necessary. We investigate the range-wide population genetics of Tetraopes texanus (Coleoptera: Cerambycidae), which provides a useful model of grassland insects due to its’ habitat specificity, limited dispersal range, and unique biology. Tetraopes texanus occurs primarily in Texas and Oklahoma, but also occurs in Black Belt prairies of Mississippi and Alabama. Mitochondrial and nuclear DNA (RAD-seq) analysis identified two distinct population clusters of T. texanus corresponding to the Texas and Oklahoma population and the Mississippi and Alabama population. Demographic models indicate ongoing, though incomplete, isolation of the two populations, with estimated dates of divergence in the mid-Pleistocene, coinciding with the end of a glacial period and a shift in glacial interval.