Tobacco Budworm Control in Caged Cotton With a Resistant Variety, Augmentative Releases of Campoletis sonorensis, and Natural Control by Other Beneficial Species1234

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Abstract
A tobacco budworm, Heliothis virescens (F.), population in field cages deposited ca. 1/2 as many eggs on a nectariless-high terpenoid-hirsute line of colton (XG-31) as on a nectaried-normal terpenoid-hirsute line (M-8). Fewer small larvae developed to medium size on XG-31 than on M-8, indicating small larval mortality most likely due to the high terpenoid content. About 8 times more medium-size larvae and twice as many large larvae were present on M-8 as on XG-31 in the F1 insect generation. Releases of Campoletis sonorensis (Cameron) resulted in 81–100% parasitism of medium larvae and, thus, considerably fewer large larvae. A native parasite, Trichogramma pretiosum Riley, and a predator, Orius insidiosus (Say), also preyed heavily on the tobacco budworm population. As a result, F2 tobacco budworm larval populations did not develop in the XG-31 plots where C. sonorensis was released. The numbers of small- and medium-sized tobacco budworm larvae also were greatly reduced in the M-8 parasite release plots. The nectariless XG-31 had fewer cabbage looper, Trichoplusia ni (Hübner), eggs and larvae than the nectaried M-8, but the high terpenoid content of XG-31 did not significantly affect numbers of cabbage looper larvae.