Using genomic data to infer evolutionary processes in the asexual parasitoid Microctonus aethiopoides

This study explores the population genomics of Microctonus aethiopoides, an asexual (thelytokous) parasitoid wasp introduced to New Zealand in 2006 for classical biological control of clover root weevil (Sitona obsoletus). Using whole-genome resequencing of 43 individuals from five populations,one from the original Irish source and four from New Zealand, we investigated spatial and temporal genomic variation. Results revealed two distinct genetic clusters, likely due to the establishment of multiple haplotypes. Patterns of high heterozygosity and short homozygous tracts are consistent with automixis and more likely by central fusion, while low linkage disequilibrium raises the possibility of occasional sexual reproduction. These findings enhance our understanding of how asexual biocontrol agents persist and adapt post-release, with implications for their long-term efficacy in changing environments.