Toxicity effect of Azadirachta indica extracts against Aedes aegypti larvae (Diptera:culicidae)

Abstract

In recent years, the usage of environmental friendly and biodegradable natural insecticides of plant origin have received and renewed attention as an effective agent for disease vector control. For date, there is no vaccine for dengue which is spread by the bite of infected Aedes mosquitoes. This study was carried out to examine the comparison of effect between three parts of Azadirachta indica plants that were extracted and tested against Aedes aegypti larvae. Fruit, leaf and bark of A. indica was extracted using 98.9% of methanol and tested against third instar Ae. aegypti larvae under laboratory condition. Exposure was done for 24 hours in the concentration of 0.1250, 0.2500, 0.5000, 1.0000 and 2.0000 mg/ml. LC50 values obtained for crude extract of A. indica fruit, leaf and bark were 0.2730, 0.3041 and 0.4581 mg/ml. There was significant difference (P<0.05) for fruit, leaf and bark. This shows that each part provides different level of toxicity effect for vector control which is friendly to the environment with fruit extract posses higher toxicity effect. This study revealed that the extracts from A. indica are promising as botanical inseticides against Ae. aegypti.