Efficacy of Bacillus sphaericus 2362 against larvae of Anopheles gambiae under laboratory and field conditions in West Africa.
A flowable concentrate of Bacillus sphaericus (Neide) strain 2362 was applied against Anopheles gambiae Giles s.l. mosquito larve in small plot field trials in Bobo-Dioulasso area. Burkina-Faso. Third and fourth instar larvae were controlled for 10-15 days with a dosage of 10 g/m2, 3-10 days with 1 or 0.1 mg/m2, and 2 days with 0.01 g/m2. Complete elimination of larval populations required 1 x 10(2) to 2 x 10(3) viable spores/ml in the larval feeding zone. After treatment, the total numbers of viable spores decreased in the ponds, due to ingestion of spores by non-target as well as target organisms and/or loss of viability of some spores by sunlight. This formulation was less effective against An. gambiae than against Culex quinquefasciatus Say larvae, both in laboratory bioassays and under field conditions.
Nicolas
L
L
OCCGE/ORSTROM Institut Pierre Richet, Bouaké, Ivory Coast.
Darriet
F
F
Hougard
J M
JM
D000818:Animals; D000852:Anopheles; D001407:Bacillus; D002050:Burkina Faso; D005618:Fresh Water; D007814:Larva; D010572:Pest Control, Biological