Insecticidal Resistance and Counter Mechanism in Mosquitoes: A Coevolutionary Trade-off

Mosquitoes are a global health risk, yet eradication efforts have been rendered futile due to the exponential rise of insecticide resistance arising in mosquitoes. Toxic chemical resistance can manifest in various ways in mosquitoes, including behavioural, physiological, metabolic and genetic mechanisms. They have developed precise strategies to combat the insecticidal action in maintaining their population, and, in doing so, they have acquired tolerance to diverse toxic chemicals through different ways including enhanced metabolic detoxification genes, such as P450, esterase, GST, overexpression, and alterations of cuticular proteins and structural modifications in voltage-gated sodium channel, GABA receptors, and AChE genes. However, the depth of knowledge and research on gene regulation and mechanisms and how quickly they can develop resistance to insecticides is remarkably low. These genetic and metabolic alterations provide mosquitoes with a greater level of toxicant resistance. Using insecticides against mosquitoes entails trade-off costs, such as a reduction in body size, an elongation of the larval development period and a decrease in the female adult longevity. As natural selection affects mutations in coding gene sequences, comprehensive genome sequencing in various mosquito strains will open new possibilities in designing revolutionary pesticides to kill mosquitoes selectively.