Anopheles stephensi L. is the primary vector of malaria, infecting more than 500 million humans each year. Present study evaluated the compatibility of the organophosphate insecticide, temephos and mosquito-pathogenic fungus, Aspergillus flavus against third instar larvae of An. stephensi. Toxicity was assessed in different combination ratios, 1:1, 1:2 and 1:4. All the experiments were conducted according to WHO standard procedure. The mortality data were recorded after 24 and 48hrs of treatment. Fungal infection increased temephos induced mortality rate at 1:1 as compared to other ratios. The LC50 values of 1:1 were 0.0015 and 0.0011 ppm and LC90 values with 0.0045 and 0.0019 ppm after 24 and 48 hrs of post exposure, respectively. Combining A. flavus with temephos induced a higher impact on mosquito survival than the use of these control agents alone. The observed synergistic efficacy shows the potential for integrated fungus-insecticide control measure to dramatically reduce malaria transmission due to enhanced larval mortality and enable control at more moderate levels of coverage even in areas where insecticide resistance has rendered essentially ineffective.
Sweta Bhan, Shrankhla, Lalit Mohan, C.N. Srivastava. Larvicidal toxicity of Temephos and entomopathogenic fungus, Aspergillus flavus and their synergistic activity against malaria vector, Anopheles stephensi. Journal of Entomology and Zoology Studies. 2013; 1(6): 55-60.