ABSTRACT

A method outlined by the Scientific Advisory Panel to the Environmental Protection Agency (US Environmental Protection Agency, 1998) was employed to investigate the high-dose expression of the Dow AgroSciences' cotton line MXB-13 (Cry1Ac/Cry1F proteins). Field-plots of cotton plants expressing and non-expressing the Bt proteins were inoculated with >270,000 tobacco budworm (Heliothis virescens [F.]) in three different locations over a period of 56 days. This inoculation regime, plus the natural occurrence of other Lepidoptera, resulted in recovery of only 3 tobacco budworm neonates, 5 cotton bollworms (Helicoverpa zea [Boddie]), 3 cabbage loopers (Trichoplusia ni [Hübner], and no soybean loopers (Pseudoplusia includens [Walker]) in the MXB-13 Bt-cotton plants. In non-Bt cotton (PSC-355 near-isoline variety) 616 tobacco budworms, 253 cotton bollworms, 1,721cabbage loopers and 157 soybean loopers were recovered utilizing the same sampling regime.

MXB-13 cotton represents an important tool to manage tobacco budworm and other lepidopteran pests, adding to the sustainability of other environmentally sound pest control alternatives.