Response of Plodia interpunctella to treatments with different strains of Bacillus thuringiensis (Lepidoptera: Pyralidae).
The Indian meal moth, Plodia interpunctella (Hübner 1813) is one of the most serious lepidopteran pests of stored grains in China and around the world. Bacillus thuringiensis (Bt), an entomopathogenic bacterium, is a useful alternative control agent for this pest. In this study, the toxicity of a collection of 122 isolates of B. thuringiensis was preliminarily assessed against P. interpunctella. Afterwards, 3 strains that demonstrated significantly greater potency than the standard strain against Lepidoptera, B. thuringiensis serovar kurstaki HD-1, were selected and these were analyzed in more detail. Isolates IMM408 and IMM130 were most toxic with LC50 of 1.24 µg/ml and 2.86 µg/ml, respectively. IMM-408 was found to produce 135 kDa crystal protein, and contained cry1Ab9, cry1Ca1, cry1Da1 and cry2 gene. Potentials of the inclusion of these strains for control of lepidopteran pests are discussed.