Patterns of genetic variation and host adaptation in an invasive population of rhopalosiphum padi (Hemiptera: Aphididae)

Abstract

Adaptive changes to local conditions are often thought to be required for successful invasions. However, there are also successful invasive asexual species that may have limited potential for evolutionary change. The bird cherry-oat aphid, Bhopalosiphum padi (L.) (Hemiptera: Aphididae), is thought to have been introduced in Australia 100 yr ago and is now an established pest of cereal crops. Here, we use mitochondrial DNA, cytochrome c oxidase subunit I, and nuclear microsatellites to characterize the genetic diversity in invasive R. padi. Asexual reproduction was detected and clonal diversity was low; with two multilocus genotypes, Rp1 and Rp2, dominating all populations. No geographic or h..