Bacillus thuringiensis serovar israelensis (Bti) is a group of bacteria use as biological control agents for larvae stages of certain Dipterans. Bti produces toxins which are effective in killing various species of mosquitoes, fungus gnats, and blackflies, while having almost no effect on other organisms. Indeed this is one of the major advantages of B. thuringiensis products in general - they have very few, if any, non-target effects.