Forest and Western tent caterpillars : Malacosoma disstria Huber and M. californicum pluviale (Dyar) (Lepidoptera: Lasiocampidae)

Several web-spinning caterpillar species attack hybrid poplars in eastern Oregon and Washington. In addition to forest and western tent caterpillars, the fall webworm [Hyphantria cunea Drury (Lepidoptera: Erebidae)] is another serious defoliator. Our objective is to alert professional pest managers to potential threats these larvae pose to poplar biomass production. Management decisions should be based upon an accurate identification of the pest, knowledge of the pest’s life history, monitoring their population, and having a management strategy to control these pests