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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/5618

Title: The effectiveness of Bacillus Sphaericus formulation for malaria vector control in Kumasi
Authors: Baffour-Awuah, Sandra
Issue Date: 3-May-2012
Abstract: The vast majority of malaria deaths, about 90%, occur in Africa where malaria also presents major obstacles to social and economic development. Mortality from malaria results from severe infection caused by Plasmodium and transmitted by Anopheles mosquito. In recent times, attempts at curbing malaria include: vector and parasitic control which involves drugs, insecticides and biological control measures. There have been reported cases of mosquito resistance against major insecticides throughout various parts of the world. Biological control agents do not kill non-target organisms. The ecosystem is therefore not disturbed and predators of the larvae can feed on the rest of the larvae that hatch after the effect of the biolarvicide has worn out. This project aimed at using an environmentally safe microbial control agent against the Anopheles larvae, the vector of malaria. The microbial control agent that was used was in the form of Water Dispersible Granular formulation (WDG) of Bacillus sphaericus (Bs Vectolex®, Valent BioSciences Corporation Illinois, USA). The study was divided into two main parts: phase 1and phase 2. Phase 1 involved laboratory studies where the optimum lethal laboratory concentration of the biolarvicide was determined. In phase 2, there were controlled field trials during the rainy season and repeated in the dry season, where optimum lethal field application dosage of the biolarvicide was determined. The residual effect of the biolarvicide was determined. The study was conducted over a one and half year period. At the end of the laboratory study it was observed that mosquito larvae were highly susceptible to the biolarvicide (Bs Vectolex®) with LC50 and LC95of 0.0027mg/l and 0.0086mg/l respectively after 24 hours of exposure. The controlled field trial revealed that 0.5mg/l was as effective and efficient as the 1.0mg/l concentration during both the rainy season (p=0.2820) and the dry season (p=0.8578). The residual effect of the Bs formulation during the rainy season lasted for 12days while that for the dry season was 10days for both concentrations. The biolarvicide proved to be an effective tool for reducing malaria vector population therefore potential for reducing malaria prevalence. Its cost effectiveness coupled with its efficacy and existence of residual effect makes it ideal for vector control via killing of larvae. This will lead to a reduction in the need for chemical applications such as insecticides, thereby achieving considerable improvement in public health and in the economy.  
Description: A thesis submitted to the School Of Graduate Studies, Kwame Nkrumah University of Science and Technology, (K.N.U.S.T.) in partial fulfilment of the requirements for the award of Mphil Degree in Entomology, May-2012
URI: http://hdl.handle.net/123456789/5618
Appears in Collections:College of Science

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