Purple loosestrife, Lythrum salicaria L., is an introduced Eurasian perennial herb that has been in North America since the early 1800s (Thompson et al. 1987). Purple loosestrife has been considered a serious threat to the integrity of North American wetlands (Thompson et al. 1987, Blossey et al. 2001a). L. salicaria has been the target of a significant North American project using biological control to combat it (Malecki et al. 1993, Blossey et al. 2001a)
