A Larvicide (alternatively Larvacide) is an insecticide that is specifically targeted against the larval life stage of an insect. Larvacides may be contact poisons, stomach poisons, growth regulators, or (increasingly) biological control agents.

Biological control agents, such as Bacillus thuringiensis, also known as Bt, which is is a bacterial disease specific to Lepidopteran caterpillars and Bacillus thuringiensis israelensis, also known as Bti, which affects larval mosquitoes and some midges have come into increasing use in recent times.

Larviciding techniques can also include the addition of surface films to standing water to suffocate mosquito wigglers, or the genetic modification of plants so that they naturally produce a larvicide in plant tissues.

Biological pest control Genetic engineering Pesticides