Ecological Consequences of Transient Outbreaks of Siberian Larch Casebearer,Coleophora sibiricella Flkv., in the Udmurt Republic

A transient population outbreak of the Siberian larch casebearer, Coleophora sibiricella Flkv. (Lepidoptera, Coleophoridae), in a protective forest strip and its consequences for the host tree species (Larix sibirica Ledeb.) have been studied for the first time. It has been shown that one-time complete defoliation by this pest and the following infestation by xylophagous insects result in tree death, while the productivity of surviving trees decreases significantly. The results of this study indicate that the Siberian larch casebearer is a major phyllophagous pest of larch and that its populations must be monitored by specialists in forest pathology.