Sampling Distributions of Larch Casebearer, Coleophora laricella , on Western Larch 1

Abstract

Intensive sampling of larch stands in northern Idaho shows that densities of overwintering larch casebearer larvae are clustered on the distal tips of branches. There is no difference in densities of pupating larvae on roadside larch trees as opposed to larch trees interior to a stand. With appropriate scaling, sample densities of overwintering and pupating larvae on the same or different plots can be compared. The distributions of sample densities among diverse larch stands are similar enough that a standardized sequential procedure can be used to efficiently and confidently monitor predicted defoliation of the larch trees. An appropriate sampling technique is presented.