Patent ID: 8802389

Claim:
A method of screening a lepidopteran for resistance to a Bacillus thuringiensis (B.t) insecticidal Cry 1 protein that is toxic to lepidopterans, wherein said lepdopteran is of a species known to develop resistance to said Cry 1 protein, wherein said method comprises collecting a lepidopteran from a field of a B.t.crop, obtaining a gut cell membrane sample from said lepidopteran, running said sample on a gel to identify an approximately 68 kDa protein band on said gel, measuring said 68 kDa protein for an amount of alkaline phosphatase enzymatic activity, and comparing said amount to a control level of alkaline phosphatase enzymatic activity determined from a gut cell membrane preparation from a control insect of known susceptibility to said Cry 1 protein, wherein resistance to said Cry 1 protein by said lepidopteran is indicated if said amount is less than that of a non-resistant insect, wherein said non-resistant insect is of the same genus and species as said lepidopteran.