Dispersal of Bacillus thuringiensis Spores by Nonsusceptible Species of Stored-grain Beetles12

Rhyzopertha dominica (F.), Oryzaephilus surinamensis (L.), Tribolium castaneum (Herbst), T. confusum Jacquelin duVal, Cryptolestes pusillus (Schönherr), Sitophilus granarius (L.), and S. oryzae (L.) were not appreciably affected by a commercial formulation of Bacillus thuringiensis var. kurstaki on wheat or a flour-cornmeal mixture at 100 or 500 mg/kg. However, R. dominica, S. oryzae, T. castaneum, and T. confusum transferred viable spores from treated to untreated wheat by carrying them externally or passing them with their feces.