Mosquito Larvicides

Bacillus thuringiensis subspecies israelensis (Bti) is a naturally occurring bacterium found in soils. Adding Bti to standing water can prevent mosquito breeding and the spread of mosquito-borne diseases.

Bti contains spores that kill mosquito larvae (and blackfly and fungus gnat larvae), but are harmless to other animals, plants, and people. Bti has been found to be very effective in reducing larval mosquito populations. The Vector Control Program uses Bti for mosquito control.

Bti for residential mosquito control can be purchased online, and in hardware and garden stores, in several different forms including briquettes, granules, liquids, tablets, and pellets.


rain barrel


  • Bti larvicides are ideal for treating rain barrels, ponds, and fountains to prevent mosquito breeding.
  • Treat the water collected between the leaves of bromeliad plants with a liquid Bti larvicide to eliminate larvae.
  • Use granule larvicides in small containers like the saucers under potted plants. 
  • For best results, use products at the frequency indicated by the label.
  • Follow all safety instructions on the product label.


  (858) 694-2888