Indirect effects of the microbial pesticide, Bacillus thuringiensis var. kurstaki (B.t.k.), have been found in birds, mammals, and some parasitic insects as a result of reduced abundance of lepidopteran larvae. Salamanders are insectivores that often contain high percentages of lepidopteran larvae in their diets. This study tested the hypothesis that salamanders experience dietary shifts or reduced abundance on plots where B.t.k. is applied, as a function of decreased caterpillar abundance. Three plots in the Monongahela National Forest, Pocahontas County, WV were sprayed with B.t.k., three were sprayed with the gypsy moth nuclear polyhedrosis virus (Gypchek^®), and three remained as unsprayed reference sites. Abundance and diet composition of five species of Plethodontidae (Desmognathus fuscus, D. monticola, D. ochrophaeus, Plethodon cinereus, P. glutinosus) were studied for two years. Neither salamander abundance nor the proportions of the major prey items in their diets differed significantly between treatments. Based on prey abundance, diets of D. monticola, P. glutinosus and D. fuscus were composed of 9%, 6.1%, and 4% lepidopteran larvae, respectively, whereas P. cinereus and D. ochrophaeus contained less than 2% caterpillars in their diets. For each salamander species, the proportions of lepidopteran larvae found in diets were significantly different among all treatments; however, these differences did not follow a pattern that indicated a B.t.k. impact.