Susceptibility of Cry1F-Resistant Fall Armyworm, Spodoptera Frugiperda, to Cotton Expressing Pyramided Bt Toxins

Fall armyworm, Spodoptera frugiperda (J.E. Smith), (FAW) is an economically damaging pest in cotton and other agricultural crops in Louisiana. Fall armyworm is predominately a foliage feeder on most crops, but will also feed on fruiting structures of the cotton plant causing direct losses in yield. Since the advent of crops genetically modified to express the bacterium Bacillus thuringensis (Bt) in the late 90’s, fall armyworm control has only been an issue in conventional cotton cultivars. Recently, two strains of FAW that are highly resistant to the Cry1F protein in corn were collected from Hendry and Collier counties in Florida. These strains have been established in our laboratory on the campus of LSU in Baton Rouge, Louisiana and have been documented to be resistant to the purified Cry1F protein as well as commercial corn possessing the Cry 1F toxin. The objective of this research project is to evaluate survival and plant injury of the Cry1Fcorn-susceptible and -resistant FAW on various Bt cotton cultivars.