Comparative larvicidal activities of the four Bacillus thuringiensis serovars against a chironomid midge, Paratanytarsus grimmii (Diptera: Chironomidae).

The four reference strains of Bacillus thuringiensis, known to be pathogenic for mosquito larvae of the family Culicidae (Diptera), were examined for their larvicidal activities against a chironomid species, Paratanytarsus grimmii (Diptera: Chironomidae). Of the four, the type strain of B. thuringiensis serovar israelensis (H14) exhibited the highest activity against both early- and late-instar larvae, while the type strain of serovar kyushuensis (H11ac) and the strain 73-E-10-2 (H10, serovar darmstadiensis) showed relatively moderate toxicities. The strain HD-1 of serovar kurstaki (H3abc) had no larvicidal activity on this chironomid midge.