Plum Curculio Phylogeography
A third of the food we grow is either lost or wasted. Insects are a significant cause of this crop loss. Controlling these losses through pesticides is toxic to people and the environment. However, alternative techniques that require less chemical management are more labor intensive, more expensive for the farmer, and often require significant investments upfront to understand the ecology and behavior pests. But such investments are necessary to develop effective management plans that leverage pest and host biology in novel ways.
This project focused on a major fruit pest: the plum curculio (Conotrachelus nenuphar). This beetle is found everywhere east of the Rockies and loves to eat and lay eggs in apples, peaches, plums, cherries, and most other stone and pome fruits. The EPA has now banned the broad-spectrum organophosphate that’s been used by farmers for decades to control this and other insect pests on fruit trees. Alternative techniques that leverage the unique biology of this organism are needed.
Plum curculio adults were collected from throughout the United States and Canada in collaboration with the USDA, State University extension offices, and the IRDA in Canada. The historical population demographics were inferred from the 1,100 individuals sequenced. Population genetic and ecological niche modeling analyses reveal two genetically and potentially ecologically isolated demes that do not correspond geographically with established voltinism strains. The strains identified by this study are likely incipient species going through ecological speciation. These results underscore the point that there are reproductively isolated demes of plum curculio and, for management purposes, these should likely be treated as unique management units.
These results are being written up for publication this Fall.