Use of Bacillus thuringiensis israelensis in the field to control mosquitoes and black flies
This is only a partial list of references.

Amalraj, D.D., Sahu, S.S., Jambulingam, P., Boopathi Doss, P.S., Kalyanasundaram, M. and Das, P.K., 2000. Efficacy of aqueous suspensions and granular formulations of Bacillus thuringiensis (Vectobac) against mosquito vectors. Acta Tropica 75: 243-246.

Becker, N., 1998. The use of Bacillus thuringiensis subsp. isrealensis (BTI) against mosquitoes, with special emphasis on the ecological impact. Isreal Journal of Entomology 32: 63-69.

Becker, N. and Margalit, J., 1993. Use of Bacillus thuringiensis isrealensis against mosquitoes and blackflies. In: P. F. Entwistle, J. S. Cory, M. J. Bailey and S. Higgs (Eds.), Bacillus thuringiensis, an environmental biopesticide: theory and practice. John Wiley and Sons.: 146-170.

Curtis, C.F., 1996. Delivering biocontrol in the tropics. Nature Biotechnology 14: 265.

Lacey, L.A. and Lacey, J.M., 1981. The larvicidal activity of Bacillus thuringiensis var israelensis (H-14) against mosquitoes of the central Amazon basin. Mosquito News 41: 266-270.

Lawler, S.P., Dritz, D.A. and Jensen, T., 2000. Effects of sustained-release methoprene and a combined formulation of liquid methoprene and Bacillus thuringiensis on insects in salt marshes. Archives of Environmental Contamination and Toxicology 39: 177-182.

Are there other benefits to using Bti?

Su, T. and Mulla, M.S., 1999. Microbial agents Bacillus thuringiensis ssp. israelensis and Bacillus sphaericus suppress eutrophication, enhance water quality, and control mosquitoes in microcosms. Environmental Entomology 28: 761-767.

Does Bacillus thuringiensis israelensis kill non-target organisms? What are the disadvantages of using Bti?
There is some evidence that chironomids are affected, but also evidence that Bti is far less harmful to ecosystems than other agents. Sometimes the alternative is not to do nothing, so the comparison has to be with what otherwise would be used.

Liber, K., Schmude, K.L. and Rau, D.M., 1998. Toxicity of Bacillus thuringiensis var. israelensis to chironomids in pond mesocosms. Ecotoxicology 7: 343-354.

Pont, D., Franquet, E. and Tourenq, J.N., 1999. Impact of Bacillus thuringiensis Variety israelensis treatments on a Chironomid (Diptera Chironomidae) community in a temporary marsh. Journal of Economic Entomology 92: 266-272.

How does Bacillus thuringiensis israelensis (and related toxins) kill mosquitoes? The toxin and mode of action
Here are a few papers, there are more.

Drobniewski, F.A. and Ellar, D.J., 1989. Purification and properties of a 28-kilodalton hemolytic and mosquitocidal protein toxin of Bacillus thuringiensis subsp. darmstadiensis 73-E10-2. Journal of Bacteriology 171: 3060-3067.

Yamagiwa, M., Kamauchi, S., Okegawa, T., Esaki, M., Otake, K., Amachi, T., Komano, T. and Sakai, H., 2001. Binding properties of Bacillus thuringiensis CryrA toxin to the apical microvilli of larval midgut of Culex pipiens. Biosci. Biotechnol. Biochem. 65: 2419-2427.

Will mosquitoes develop resistance to Bacillus thuringiensis?
Here are a few papers that address that.

Ferré, J. and Van Rie, J., 2002. Biochemistry and genetics of insect resistance to Bacillus thuriingiensis. Annual Review of Entomology 47: 501-533.

Georghiou, G.P. and Vasquez, M.G., 1982. Assessing the potential for development of resistance to Bacillus thuringiensis var. israelensis toxin (BTI) by mosquitoes. Mosquito Control Research Annual Report: 80-81.

Gill, S.S., Cowles, E.A. and Pietrantonio, P.V., 1992. The mode of action of Bacillus thuringiensis endotoxins. Annual Review of Entomology 37: 615-635.

Goldman, I.F., Arnold, J. and Carlton, B.C., 1986. Selection for resistance to Bacillus thuringiensis subspecies isrealensis in field and laboratory populations of the mosquito Aedes aegypti. Journal of Invertebrate Pathology 47: 317-324.

McGaughey, W.H. and Oppert, B., 1998. Mechanisms of insect resistance to Bacillus thuringiensis toxins. Israel Journal of Entomology 32: 1-14.
(This paper is more general and addresses resistance to Bacillus thuringiensis toxins affecting not only mosquitoes but other insects.)

Treatments with Bacillus thuringiensis must be repeated often. Some promising developments.
Researchers are testing putting the Bti toxin into other organisms that may continue to grow, so the mosquito larvae will be exposed to the Bti toxin for a longer period of time. One example of this is:

Manasherob, R., Bendov, E., Margalit, J., Zaritsky, A. and Barak, Z., 1997. Raising activity of Bacillus thuringiensis var. israelensis against Anopheles stephensi larvae by encapsulation in Tetrahymena pyriformis (Hymenostomatida, Tetrahymenidae). Journal of the American Mosquito Control Assoc. 12: 627-631.

Manasherob, R., Ben-Dov, E., Zaritsky, A. and Barak, Z.e., 1998. Germination, growth, and sporulation of Bacillus thuringiensis subsp. israelensis in excreted food vacuoles of the protozoan Tetrahymena pyriformis. Applied and Environmental Microbiology 64: 1750-1758.

Why Bacillus thuringiensis?
One reason to develop and use Bti is to reduce dependency on other agents used to control mosquitoes. Mosquitoes developing resistance to insecticides has been a major problem for mosquito control; even newer methods seem to be at risk of losing their effectiveness. The more and different methods available, the more wisely they can be used in managing mosquitoes while minimizing harms and risks.

Cornel, A.J., Stanich, M.A., McAbee, R.D. and Mulligan, F.S.I., 2002. High level methoprene resistance in the mosquito Ochlerotatus nigromaculis (Ludlow) in central California. Pest Management Science 58: 791-798.

Copyright © 1996 & 2003, E. Willott.
Last update Feb 22, 2003.