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

Transgenic Populus plants (clone NC5339) expressing a Bacillus thuring iensis 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 exper ienced significant mortality following exposure to the transgenic d-en dotoxin. Gypsy moths were better able to recover after transfer to art ificial diet than were forest tent caterpillars. Transgenic leaves det erred feeding by both species in behavioral choice tests. Four additio nal transformants contained, but did not express the d-endotoxin gene. Results are discussed in terms of efficacy, plant deployment strategi es, ecosystem stability, and tree improvement.