Larvicides are a type of insecticides that are specifically designed to destroy larvae, insects in the larva stage. They are most commonly used against mosquitoes and flies. Larvicides have several types of methods of action, such as contact, ingestion, growth regulators, and biological control agents. Insects usually have three life stages: egg, larva, and pupa. By using larvicides, growth, and development into an adult insect is impeded.
Biological control agent Bacillus thuringiensis, also known as BT, is a bacterial disease of caterpillars specifically. Bacillus Thuringiensis Israeleniss is known as BTI and it affects the larvae of mosquitoes and flies. It has begun to be used more increasingly lately. BTI are naturally occurring soil bacteria, but there are products that are usually in the form of granules and pellets, which are spread on the surface of stagnant water. When mosquito larvae ingest the bacteria, toxins destroy their digestive tract.
Chemical agents, such as methoprene, are insect growth regulator agents that interrupt the growth cycle for insect larvae, preventing them from developing in the aft stage. Temephos is an organophosphate that prevents mosquito larvae to develop resistance to bacterial larvicides.