Flighted spongy moths (Lepidoptera: Erebidae), defoliating invasive forest pests

Abstract Flighted spongy moth, Lymantria dispar asiatica Vnukovskij and Lymantria dispar japonica Motschulsky, is a highly destructive defoliator that threatens forest and urban trees in both its native Asian range and where introduced. This moth goes through outbreak periods with very high population numbers resulting in defoliation of almost all deciduous and coniferous trees and potentially severe human allergic reactions to the insect hairs and scales. Adult females are capable of strong ascending flight and at night are attracted to lights where they lay their egg masses on surrounding surfaces. This has resulted in flighted spongy moth hitchhiking multiple times to new areas as egg masses, or occasionally as pupae, on ships and their cargo. Flighted spongy moths have a broad host range that includes several hundred tree species, both broadleaf and conifer. Identification of stages and species, life history, and ecology are reviewed here. There are few biological differences between the 2 subspecies, but L. dispar japonica tends to be larger and flies at a slightly different time of day than L. dispar asiatica. Both eradication (in introduced areas) and management require detection which is primarily accomplished using male pheromone traps and egg mass surveys. Populations are controlled by various natural and managed methods including parasitoids, predators, pathogens, microbial pesticides registered for aerial and ground application, mating disruption (applying pheromone in various formulations), and aerially spraying insect growth regulators. Synthetic insecticides are rarely used due to public concerns regarding unintended nontarget impacts.