Laboratory evaluation of Vectobac as against Aedes aegypti in Monterrey, Nuevo León, Mexico.
Intensive use of the organophosphate insecticide malathion against adults and temephos against larvae of Aedes aegypti in Mexico over the past 30 years has led to problems requiring the use of new larvicides. Toward this objective, Bacillus thuringiensis var. israelensis (Bti), a target-specific and environmentally safer control agent, was evaluated. Laboratory bioassays were done to determine the susceptibility of 2nd- and 3rd-stage larvae of Ae. aegypti to Vectobac 12 AS (aqueous suspension, 600 ITU/mg). A median lethal concentration of 0.0104 ppm and a 95% lethal concentration of 0.18 ppm were determined after 24 h of exposure to the agent. The values obtained were adjusted for field application and were further tested in the field by the State of Nuevo León, Mexico Vector Control Program. Suspensions of Bti were poured into pipe-water trucks and transferred to domestic 200-gal metal water drums. Larval populations were reduced during a 2-week study period. However, residents complained about a fine dusty film on the water surface. Nevertheless, these results are promising for future Bti field applications.
Ponce G
Gustavo
G
Laboratorio de Entomología Médica, Facultad de Ciencias Biológicas, Universidad Autonoma de Nuevo León, Apartado Postal 391, San Nicolás de los Garza, Nuevo León 66450, Mexico.
Flores
Adriana E
AE
Badii
Mohammad H
MH
Rodríguez-Tovar
M Luisa
ML
Fernández-Salas
Ildefonso
I
D000330:Aedes; D000818:Animals; D001413:Bacillus thuringiensis; D005069:Evaluation Studies as Topic; D007814:Larva; D008800:Mexico; D010572:Pest Control, Biological