Differences in susceptibility and physiological fitness of Mexican field Trichoplusia ni strains exposed to Bacillus thuringiensis.

The use of different commercial Bacillus thuringiensis (Bt) products in the Bajio guanajuatense area in Mexico began 12 yr ago, and resistance to Bt in this area has been reported for Plutella xylostella (L.) The current study provides a baseline response and resistance potential to Bt in field and laboratory strains of Bajio Trichoplusia ni (Hübner). Differences in susceptibility to Bt among T.

Characterization of Mexican Bacillus thuringiensis strains toxic for lepidopteran and coleopteran larvae.

Bacillus thuringiensis strains C-4, C-9, GM-7, and GM-10, isolated from northeast Mexico and selected for their high toxicity against lepidopteran and coleopteran pests, were characterized following United States Environmental Protection Agency (EPA)'s guidelines. Flagellar serotyping revealed that GM-7 and GM-10 belonged to serotype aizawai, whereas C-4, C-9 corresponded to the kumamotoensis serotype. GM-10 and C-9 were also shown to be the most effective against lepidoptera and coleoptera larvae, respectively.