Mosquito control programs worldwide have been evaluating the feasibility to implement biological control strategies by using Bacillus sphaericus (Bs) and/or B. thuringiensis serovar israelensis (Bti). A comprehensive review is presented here to assess the potentiality of biological control agents in mosquito control operation. Vector control is primordial and very essential means for controlling transmission of filariasis, malaria, Japanese encephalitis and dengue in human society. Over the last few decades, there is growing realization that alternate methods to synthetic chemical control needs to be studied and perfected. In the last decade the bacilli based mosquito larvicides popularly known as biological larvicides are becoming more popular in vector management program the world over. The toxicity to mosquito larvae is due to crystal toxins encoded by specific genes. The major advantages of these biolarvicides are reduced application cost, safety to environment, human beings, animals and other non-target organisms. This special review paper explores the importance of bacterial toxin in controlling vector mosquitoes and the tactics for managing resistance to the mosquitocidal bacteria which include rotating different mosquitocidal strains and using genetic engineering to produce new combinations of toxins. This paper also provides a focus on continuous research toward identification of novel mosquitocidal toxins suitable for use if resistance to existing toxins.
Key word: Vector control, synthetic chemicals, biopesticides, mode of action, resistance, bioengineering.