DOI: 10.36347/sajb.2014.v02i09.019

Pages: 651-658

Mosquitoes are the most important vectors which transmit wide range of life threatening diseases like malaria and dengue accounting for global mortality and morbidity with increased resistance to common pesticides. Since chemical insecticides pose serious threats to environment, human, and also other non-target organisms, the present study was undertaken to synthesize titanium dioxide nanoparticles using Aspergillus niger. The biocidal efficacy of Titanium dioxide nanoparticles against Aedes aegypti larvae was investigated and biochemical profile of the treated larvae was also evaluated. The TiO2 nanoparticles were characterized by UV visible spectroscopy, Scanning Electron Microscopy, and XRD. The larvicidal activity of these nanoparticles against II and III instar larvae of Aedes aegypti was found to be concentration dependant. IC50 values of TiO2 nanoparticles against II and III stage larvae were found to be 6.7ppm and 8.4ppm respectively. The results revealed that III instar larvae were more resistant to low concentration of TiO2 when compared with that of II instar larvae, which might be due to structural development. Biochemical profile in the treated larvae indicates that TiO2 toxicity reduced the levels of protein, cholesterol, and activities of acid/alkaline phosphatases, and lactate dehydrogenase whereas carbohydrate content was found to be increased in the treated larvae. Fungal generated TiO2 induces the larval mortality and alter the metabolism of essential biomolecules leading to development of effective strategy to control Aedes aegypti at its larval stage.