Saprophagous caterpillars (Lepidoptera: Noctuidae: Herminiinae): Effect of Bacillus thuringiensis var. kurstaki application in forest and laboratory settings

The larvae of the Herminiinae are macrodecomposers of forest leaf litter. Eight species were studied to determine the effects of aerially applied Btk. Adults were collected weekly by light trap for 7 consecutive seasons. The first 2 years provided baseline information, followed by 2 years of Btk treatment and 3 post-treatment years. Idia aemula (Hubner)(Lepidoptera: Noctuidae) larvae were collected from control plots and treated with Btk in the laboratory to determine susceptibility. Untreated larvae were reared to adulthood and mated to obtain information on their biology.;Differences in light trap counts between years were significant for all 8 species. Forest effect was significant for 5 study species. Idia aemula larvae were susceptible to Btk treatment in the laboratory. Treatment effects were not observed in the field. The discrepancy between the effects of Btk applied in the field and the laboratory may be attributed to the protected habitat of Herminiinae larvae.