Insecticidal susceptibility and resistance of phytochemicals over synthetic larvicidesagainst mosquito species (diptera): a review

The diversity and proliferation of mosquitoes depends on the availability of breeding sites, sources and abiotic factors of the environment. Mosquito species serves as a vector for most of the life threatening diseases like malaria, chikungunya fever, yellow fever, dengue fever, filariasis, Japanese encephalitis, West Nile virus infection, Zika virus etc. To control the growth of these species many chemical pesticides are used like malathion, phenothrin, pyrethrins and temphos. But these insecticides are now showing less effect on the target species and are also dangerous for the non-target species. Under the Integrated Mosquito Management (IMM), alternative strategies for mosquito control were highlighted. The steady use of manmade insecticides is the origin of toxic substance bio magnification in the food chain, development of resistance in vector species and adverse effects on environmental quality and non target organisms including human health. On the contrary phytochemicals are harmless, convenient and cheap, biodegradable and manifest wide range of precise activities against different species mosquitoes. In this review, the present day knowledge onkind of mosquito species, the diseases they transmit as vectors, their life cycle and phytochemical sources have been studied. The mosquito species which are vectors of many diseases have developed resistance capacity against chemical larvicides and are showing less mortality rate. Whereas phytochemicals are a blend of chemical compounds therefore the mosquitoes are more susceptible against them with a very high mortality rate. A comparison between chemical and natural larvicides with respect to susceptibility and resistance for mosquito control have been reviewed.