Lufenuron: A Potential Chitin Synthesis Inhibitor Against Aedes aegypti L.

Abstract

Chemical control of dengue vector, Aedes aegypti is impaired due to development of resistance to conventional insecticides. Insect Growth Regulators (IGRs) are considered more suitable and effective vector control agents as they specifically inhibit chitin biosynthesis, a process absent in vertebrates, and impose less adverse effects on beneficial insects and the environment. Present study investigates Lufenuron, a Chitin Synthesis Inhibitor (CSI), as a control agent of Ae. aegypti. Different instars of Ae. aegypti were exposed to a range of concentrations of Lufenuron as per WHO protocol. The investigations showed the effective hormone-mimetic effect of Lufenuron resulting in the formation of a significant number of larval-pupal and pupal-adult intermediates with the maximum number observed on exposure to L3 (L-P=17%, P-A=21%). Approximately 20% of L2 instars either could not moult and remained trapped inside the new exuviae or possessed bulged abdomen while some showed ruptured exoskeleton. The results showed increase in IE 30 from L1 (0.00010 ppm) to L4 stage (0.00013 ppm); the L2 stage exhibiting maximum IE 30 (0.00025 ppm). The median emergence suppression (IE 50 ) doses of the Lufenuron were found to be 0.00057 ppm for L1, 0.00047 ppm for L2, 0.00050 ppm for L3 and 0.00096 ppm for L4. The results also revealed increased duration of larval development and inability of pupae to develop into adults, as compared to the controls. The investigations indicate the potential use of Lufenuron as the control agent of Ae. aegypti. Further research is being conducted to understand its mode of action to develop effective control strategies.