We grew larvae of tobacco budworm, cotton bollworm, and fall armyworm on detached plant tissue of 5 transgenic cotton lines; Coker 31, the parental non-transgenic line; and DES 119, the adapted cultivar. The larvae were placed on plant tissue in individual cells of multicell trays and held for growth in an incubator set at 80 F.

When neonate tobacco budworm, Heliothis virescens, larvae were placed on the cotton lines, growth and survival of tobacco budworm larvae at 6 days were significantly reduced on each transgenic line when compared to Coker 31. When 3-day-old diet fed tobacco budworm larvae were placed on cotton tissue and allowed to grow until pupation or death, no larvae survived until pupation on any of the 5 transgenic lines; however, they did pupate on Coker 31 and DES 119. When 6-day-old, diet fed tobacco budworm larvae were placed on plant tissue for 6 days, TG 3, TG 4, and TG 5 produced the smallest larvae; however, larvae were significantly smaller on each of the 5 transgenic lines than on Coker 31. Survival of these larvae ranged from 60 to 96% on the transgenic lines.

Larvae of the cotton bollworm, Heliothis zea, were not affected as much by the transgenic lines as were larvae of tobacco budworm; however, each of the transgenic lines produced significantly smaller larvae and significantly fewer larvae than Coker 31. Larvae were smaller and fewer on TG 1 and TG 2 than on TG 3, TG 4, or TG 5.

When neonate larvae of fall armyworm, Spodoptera frugiperda, were placed on plant tissue, each of the transgenic lines except TG 3 significantly reduced weight of fall armyworm larvae at 6 days compared to Coker 31; however, survival was only significantly reduced on TG 1 and TG 2 compared to Coker 312.

When 6-day-old fall armyworm larvae were placed on plant tissue and allowed to grow for 6 days, none of the transgenic lines reduced larval survival below survival on Coker 31. Larvae grown on TG 1 and TG 2 were significantly smaller than larvae grown on Coker 31; however, larvae grown on TG 3, TG 4, and TG 5 were not significantly smaller than those grown on Coker 31.