Indian Journal of Science and Technology

Abstract

Objective: To investigate if insecticide resistant mosquitoes are having better vectorial capacity and more potent vectors of Plasmodium as susceptible one. Methods: The present study consists of a novel experimental system consisting of Plasmodium berghei and its vector An. stephensi, one important mechanism of insecticide resistance (detoxification of insecticide through GST mediated pathway) was investigated for their effect on vectorial capacity of mosquito in terms of intake of blood meal, early mortality, fecundity, survivability up to 14 days of post blood meal and oocyst burden. For this purpose two types of experiments were carried out using susceptible An. stephensi and insecticide resistant An. stephensi (resistant after 2% DDT exposure for three generations). Findings: The present study revealed that the specific activity of GST was significantly higher in resistant An. stephensi. Significantly high frequency of intake of blood meal was found in resistant An. stephensi. Resistant An. stephensi showed low rate of early mortality. Study of fecundity of An. stephensi showed that Plasmodium infectivity is negatively proportional to fecundity and positively co-related to survivability of An. stephensi up to 14 days of post blood feed. Higher oocyst burden was observed in resistant infected An. stephensi. Application/Conclusions: The present study revealed that GST-based insecticide resistance enhanced the vectorial capacity of the resistant vector. 

Keywords: An. Stephensi, Glutathione S-Transferases (GST), Insecticide resistance, Plasmodium berghei , Vectorial Capacity