Evaluation of Bacillus sphaericus to control breeding of malaria vectors

Bacillus sphaericus formulations (Solvay liquid 2362 and Abbott granules 2297) were tested in the laboratory and field for the control of mosquito breeding. Results of laboratory evaluation revealed that both formulations had good larvicidal activity against Culex quinquefasciatus, at 0.04 ml and 1 gm/sq m dosages respectively. Higher dosages at 5 ml liquid or 5 gm/sq m granules were required to control A. stephensi and A. subpictus. A. culicifacies required still higher dosages of Solvay (25 ml/sq m) to achieve same levels of control whereas Abbott granules were not effective even at 20 gm/sq m.