EVALUATION OF NATIVE STRAINS AND AN HD CO LLECTION OF BACILLUS-THURINGIENSIS SEROTYPE H8 AGAINST LEPIDOPTERA LARVAE

Eleven native strains of the GM code of Bacillus thuringiensis serotyp e HS and ten strains of the HD collection obtained from stored extract s were evaluated as to their toxicity against three lepidopteran pest of economic importance in Mexico (Trichoplusia ni, Heliothis virescens , and Spodoptera exigua) . Each strain was grown on molasses medium fo r the production of spore-crystal complexes. These were extracted by t he lactose-acetone coprecipitation method. Results showed that none of the GM, H8 serotype strains evaluated has a potential for biological control against the tested species and that the best HD strains were H D-116 and HD-530 serotype H8a8b against T. ni.