We compared the population genetic structure between populations of the blueberry gall midge-Dasineura oxycoccana (Johnson) (Diptera: Cecidomyiidae)-from blueberry and cranberry and determined the genetic relationships among geographical subgroups by genotyping 632 individuals from 31 different populations from their native USA regions (New Jersey, Michigan, and Georgia) and from invaded Korean regions using 12 microsatellite loci. Our population genetic analyses showed a clear separation between the two host-associated D. oxycoccana populations from blueberry and cranberry. Using data from only the blueberry-associated D. oxycoccana populations, we identified five genetically isolated subgroups. An analysis of the approximate Bayesian computation suggests that the invasive D. oxycoccana population from Korea appears to have been introduced from an unsampled source population rather than directly from its native range. Our findings will allow for an easier identification of the source of D. oxycoccana into newly invaded regions, as well as to determine their association with blueberry and cranberry, which based on our results can be considered as two distinct species.
Keywords: Cecidomyiidae; cranberry tipworm; exotic pests; host-associated differentiation; invasion route; molecular ecology.