Vectolex (B. Sphaericus)

Bacillus sphaericus, the active ingredient in VectoLex, is toxic to many species of mosquito larvae upon ingestion. The mode of action of Bacillus sphaericus (Bs) is similar to Bacillus thuringiensis israelensis (Bti) : at the time of sporulation, Bs produces a delta-endotoxin, which is toxic to many species of mosquito larvae upon ingestion.The larvae ingest the insecticide, consisting of Bs spores and crystalline toxins produced by the bacteria. Only when activated by the larva’s specific gut pH and enzymes do the crystals become toxic.