A new standard pupation shelter for sampling pupae and estimating mortality of the hemlock looper (Lepidoptera: Geometridae)

Abstract

AbstractA new standard pupation shelter for sampling hemlock looper (Lambdina fiscellaria) pupae is described and compared with the burlap band method developed by Otvos (1974; The Canadian Entomologist106: 329–31). The new pupation shelter is placed on the bole, at breast height or in the crown, to estimate population abundance and mortality. The utilization of two shelters at breast height was as efficient as the use of burlap bands to estimate hemlock looper abundance and more efficient for sampling braconid cocoons. It provided reliable estimates of braconid and tachinid parasitism but overestimated that by ichneumonids. This new pupation shelter is an inexpensive tool that can be used easily by nonspecialized personnel, thus allowing increases in the number of sample plots, which is necessary to improve detection of outbreaks of the hemlock looper. This new shelter could be used to sample other lepidopterans whose late-instar larvae aggregate in concealed pupation sites.