The Biological Control of the Malaria Vector

The call for malaria control, over the last century, marked a new epoch in the history of this disease. Many control strategies targeting either the Plasmodium parasite or the Anopheles vector were shown to be effective. Yet, the emergence of drug resistant parasites and insecticide resistant mosquito strains, along with numerous health, environmental, and ecological side effects of many chemical agents, highlighted the need to develop alternative tools that either complement or substitute conventional malaria control approaches. The use of biological means is considered a fundamental part of the recently launched malaria eradication program and has so far shown promising results, although this approach is still in its infancy. This review presents an overview of the most promising biological control tools for malaria eradication, namely fungi, bacteria, larvivorous fish, parasites, viruses and nematodes

Lysinibacillus sphaericus

Lysinibacillus sphaericus (Ls) strains that produce insecticidal proteins show high activity against mosquito larvae. The most active of these is the binary (Bin) toxin that acts following ingestion and, after midgut processing and binding to specific receptors, provokes cytopathological effects and leads to larval death. Bin toxin displays specific action against some species of medical importance (e.g. Culex and Anopheles) and it is safe to non-target organisms. These features have led to the production of biolarvicides based on this bacterium and its effectiveness to control mosquito larvae has been widely related in the literature. The field utilisation of Ls has also shown that resistance could be selected among exposed populations and the mechanisms and genes involved in this process have been described. Management strategies can be successfully employed to avoid resistance and Ls can be used within integrated programmes as a selective and efficient agent to control mosquitoes