Toxicity of Purified Proteins and the HD-1 Strain from Bacillus thuringiensis Against Lesser Cornstalk Borer (Lepidoptera: Pyralidae)

Abstract

Toxicity of cryIA(a), cryIA(b), CryIA(c), CryIC, and CryIIA proteins, and the HD-1 strain of Bacillus thuringiensis was determined against neonate lesser cornstalk borer, Elasmopalpus lignosellus (Zeller), in diet incorporation bioassays. CryIIA was the most toxic of the individual proteins with an LC 50 (micrograms protein per gram diet) of 1.94. The LC 50 (micrograms protein per gram diet) for the HD-1 strain that contains all of the above mentioned proteins except CryIC was 5.46. The toxicity of CryIIA and the HD-1 strain suggests that these compounds could be used to efficaciously control E. lignosellus in peanut fields either in typical ground applications, or in the case of CryIIA, be overexpressed in other organisms such as plants or plant-colonizing bacteria.