DOES FOREST THINNING AFFECT PREDATION ON GYPSY-MOTH (LEPIDOPTERA, LYMANTRIIDAE) LARVAE AND PUPAE

Predation on larvae and pupae of the gypsy moth, Lymantria dispar (L.) was studied in a leading-edge population in West Virginia. In 8 thinn ed and 8 uncut stands, rates of survival of lan ae and pupae were moni tored in 3 types of exclosures placed at 3 heights in the forest strat a. The abundance of small mammals was measured within each of these st ands using pitfall traps. 37% of larvae and 25% of pupae were killed b y predators over the 3 d of observations each year. Thinning did not i nfluence the proportion of larvae or pupae killed. Survival of larvae and pupae on the ground was significantly lower than that found on tre e boles or in the foliage. Differences in survival among exclosure typ es indicated that invertebrates were the major predators of larvae, an d small mammals were the major predators of pupae.