The B. thuringiensis subsp. israelensis insecticidal protein is highly toxic when ingested by mosquito larvae. Since 1982, it has been used successfully worldwide to control mosquitoes and blackflies. However, the parasporal crystal of this species sinks rapidly after it is sprayed on water, which effectively removes it from the feeding area of mosquito larvae and dramatically decreases its efficacy as a mosquitocide. To overcome this shortcoming, several approaches have been attempted. Currently, B. thuringiensis subsp.