In its native range of northern Asia, the Siberian Silk Moth can be a very serious and destructive pest of larches (Larix spp.) and soft 5-needled pines (Pinus spp.), but other conifers may also be attacked. Siberian Silk Moth larvae defoliate trees during 2-3 successive years; many trees are unable to withstand such a long period of defoliation. Outbreaks, which occur every 8 to 11 years, extend over enormous areas (many thousands of acres) and often lead to the death of entire forests. Highly stressed trees that survive the Siberian Silk Moth outbreak often then fall victim to wood borers (scolytids, cerambycids and others) that target damaged forests. Both the caterpillar and the egg mass are quite distinctive and easy to recognize. The unusual and complex 2-3 year lifecycle of the Siberian Silk Moth has made it very difficult to control in its native range.