Attacking the Larvae
There are many weapons in the war against mosquitoes, from the rolled up newspaper to sprayer trucks. But for speed and effectiveness, few techniques compare to larvicides, substances that control mosquito larvae, the pre-adult insects that feed and mature in standing water.

Biological larvicides are made from the bacteria Bacillus thuringiensis israelensis (Bti) or Bacillus sphaericus (Bsph). The bacteria produce a crystal which is poisonous to mosquito larvae, but virtually harmless to other forms of aquatic life.