Understanding a Pest: Phylogeography and Systematics of the Plum Curculio (\u3ci\u3eConotrachelus nenuphar\u3c/i\u3e)

The plum curculio (Conotrachelus nenuphar Herbst) (Coleoptera: Curculionidae) is an economically and ecologically important pest in North America but is understudied despite having a long history in the scientific literature. Its chemical ecology, life history habits, and distribution are all well characterized. However, there is a dearth of knowledge concerning the population structure and evolutionary history of the species. This study aims to use methods from evolutionary biology to better understand an agricultural pest species and provide tools to aid in its management. Existing taxonomic classifications of North American Conotrachelus species have been tested for the first time. Using a combined multigene approach, we have inferred a species phylogeny. Established species groups are well supported as monophyletic. However, the species groups identified in taxonomic keys are generally not recovered as monophyletic. Broadly sampling across the geographic distribution, we have sample over 1,000 individuals for mitochondrial DNA variation. We characterized population substructure of plum curculio populations from the full breadth of its range and reveal significant geographic and genetic structure. There is a significant north-south split that does not align with the current understanding of the plum curculio phenological strains. There are also highly structured populations corresponding to the Mississippi River and Apalachicola River basin, a pattern thought to be associated with southern refugia along the Gulf Coast. There are likely multiple refugia used over the Last Glacial Maximum. Regions of the world that are most at threat of plum curculio beetle invasion, given the organism\u27s habitat preferences, are identified across all continents and in every region where it is listed as a quarantine species. Molecular tools for diagnosing and managing the plum curculio, locally and internationally, are developed and provided for all life stages