RESPONSES OF GYPSY-MOTH (LEPIDOPTERA, LYMANTRIIDAE) AND FOREST TRENT CATERPILLAR (LEPIDOPTERA, LASIOCAMPIDAE) TO TRANSGENIC POPLAR, POPULUS SPP, CONTAINING A BACILLUS-THURINGIENSIS D-ENDOTOXIN GENE

Transgenic Populus plants (clone NC5339) expressing a Bacillus thuringiensis d-endotoxin gene significantly reduced feeding and weight gain by gypsy moth, Lymantria dispar (L.), and the forest tent caterpillar, Malacosoma disstria Hubner. Forest tent caterpillar larvae also experienced significant mortality following exposure to the transgenic d-endotoxin. Gypsy moths were better able to recover after transfer to artificial diet than were forest tent caterpillars. Transgenic leaves deterred feeding by both species in behavioral choice tests. Four additional transformants contained, but did not express the d-endotoxin gene. Results are discussed in terms of efficacy, plant deployment strategies, ecosystem stability, and tree improvement.