The forest tent caterpillar, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae) is a widespread defoliator that is native throughout most of the continental United States and Canada south of 61°N latitude. Larvae feed on a wide variety of hosts across their geographic range, but local populations perform best on local host species. Defoliation during outbreaks can strip preferred trees of all foliage and cause substantial branch mortality and growth reduction but generally does not cause much tree mortality, at least not directly. Defoliation in recreational areas reduces visitation because migrating caterpillars are viewed as nuisances and defoliated trees as unsightly. The insects, their frass, and associated damage to ornamental trees and shrubs also are nuisances for homeowners. The current importance of the forest tent caterpillar and its potential to become more important in a warmer climate warrant greater attention to its population dynamics and control options. Because 1) outbreaks of this native insect generally cause little long-term damage to forest values, 2) widespread application of insecticides is cost prohibitive, and 3) forests are increasingly valued as reservoirs of biodiversity and multiple ecosystem services, microbial insecticides, such as Bt, spinosad, and baculovirus formulations, are favored over synthetic insecticides for control of this insect when warranted. Other biorational insecticides include azadirachtin (a botanical insecticide) and insecticidal soap. Conventional synthetic insecticides include several pyrethroids (such as bifenthrin and permethrin), organophosphates (such as acephate and malathion), and carbamates (carbaryl), but these have broad nontarget effects that discourage use in forests.
Key words: forest management, defoliator, biological control, pheromone, insecticide
T.D. 2017. Biology and management of the forest tent caterpillar (Lepidoptera:
Lasiocampidae). Journal of Integrated Pest Management 8(1): 24; 1–10.
The LSU AgCenter and the LSU College of Agriculture