METHOD: Test Diet CONDITIONS: Lab METHOD NARR: Glycoalkaloids were isolated from ber and leptines from chc. Purity and quantity were determined by HPLC. Test diets were prepared with 3 different concentrations of glycoalkaloidsfhoppers during 72 hour test periods. Percent mortality on each diet was measured. RESULTS NARR: Major effects occured at the 0.09% and 0.27% concentrations, although considerable mortality occured on the solmargine and tcentration. At all concentrations, mortality was the greatest with tomatine in the diet. AUTHOR EXPLANATION: Other authors (Dahlman & Hibbs) have reported resistance to PLH using Leptine 1. The present authors speculate tharom chc only by the presence of an ester carbonyl group, a mistaken identification would account for the different resistance evaluations.