The life cycle of Pineus strobi in southwest Virginia and seasonal presence of its associated predators

The introduction of hemlock woolly adelgid, Adelges tsugae, into eastern forests has led to major losses of hemlock species, Tsuga spp., indigenous to the region. The primary tool available for managing hemlock woolly adelgid in forest settings is the use of biological control agents.  Laricobius rubidus, a known predator of the pine bark adelgid, Pineus strobi, is commonly found associated with hemlock woolly adelgid.  Laricobius nigrinus, a predator of HWA, and released in the eastern U.S. since 2003, has been found to hybridize with L. rubidus collected off of hemlocks.  This has made it essential to better understand the relationship between pine bark adelgid and its associated predators.  Additionally, there is a lack of information available on the life history of pine bark adelgid, particularly in the Appalachian region. We are studying the phenology of pine bark adelgid on eastern white pine throughout a 2-yr period, and surveying for potential natural enemies. We have found that pine bark adelgid in the southern Appalachian region goes through shorter periods of hibernation and is therefore able to complete more generations per year than populations in the more northern reaches of its range. Additionally, it has been found that many native predators associated with hemlock woolly adelgid in its introduced eastern range are also associated with pine bark adelgid.