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Mode of Action of Bti and B. sphaericus
Both Bti and B. sphaericus are naturally occurring soil bacteria, with specific activity against a narrow range of fly pests. These two active ingredients allow for the effective control of many of the world's vector and nuisance pests.


Bti (VectoBac®)

  • VectoBac's 5 proteins work once they are ingested by the target pest. 

    The proteins are activated by enzymes and the alkaline pH in the larval midgut and begin to enlarge the pores thus destroying the cells and opening the gut wall.

    Once the gut wall is destroyed the larvae can no longer eat and die within 24 to 48 hours.

  • This bacteria is not active in the "acidic guts" of humans and other animals.

B. sphaericus (VectoLex®)

  • VectoLex contains toxic protein crystals and living spores. Larvae eat VectoLex as they feed. 

    In the larvae's gut, enzymes cause the proteins to dissolve into smaller crystals called protoxins. 

    The protoxins fit themselves to receptors in the gut wall each like a key fitting a lock. Almost immediately, the protoxins begin to paralyze the gut. 

  • Within a few hours the protoxins begin to "unlock" pores in the gut wall. The spores begin to invade the body cavity through the pores where they multiply at an explosive rate The larvae usually dies within two days.