Testing for genetic differentiation among populations of the North American native cranberry fruitworm, Acrobasis vaccinii (Lepidoptera: Pyralidae), from blueberries and cranberries

Genetically distinct herbivorous insect lineages can form when each lineage is in association with a different host-plant species, a special case of ecological speciation referred to as host-associated differentiation (HAD). The frequency and circumstances surrounding HAD have not yet been fully characterized. This is especially true of agricultural systems. However, it is thought that certain characteristics within a system increase the probability that HAD will occur. These characteristics include relatively long-standing evolutionary relationships between insects and their host-plants, endophagous feeding by insects of their host-plants, and allochrony in host-plant phenologies. We assessed status of these characteristics as well as the presence of HAD in an agricultural system involving Acrobasis vaccinii (Lepidoptera: Pyralidae) associated with blueberry and cranberry.  Despite finding the characteristics that usually co-occur with HAD within our study system, we did not find the genetic signature of HAD in A. vaccinii. These findings suggest that the interaction between the characteristics which explain HAD are more complex than previously suspected.