Insecticide resistance in Culex quinquefasciatus Say, 1823 in Brazil: a review

Abstract

AbstractCulex quinquefasciatusis a successful invasive species broadly distributed in subtropical regions, including Brazil. It is an extremely annoying mosquito due to its nocturnal biting behavior, in high-density populations and it is a potential bridge between sylvatic arbovirus from birds to man in urban territories. Herein, we present a review concerning the methods of chemical control employed againstCx. quinquefasciatusin Brazil since the 1950’s and insecticide resistance data registered in the literature. As there is no specific national programme forCx. quinquefasciatuscontrol in Brazil, the selection of insecticide resistance is likely due in part to the well-designed chemical campaigns againstAedes aegyptiand the elevated employment of insecticides by households and private companies. There are very few publications about insecticide resistance inCx. quinquefasciatusfrom Brazil when compared toAe. aegypti. Nevertheless, resistance to organophosphates, carbamate, DDT, pyrethroids and biolarvicides has been registered inCx. quinquefasciatuspopulations from distinct localities of the country. Concerning physiological mechanisms selected for resistance, distinct patterns of esterases, as well as mutations in the acetylcholinesterase (ace-1) and voltage-gated sodium channel (NaV) genes, have been identified in natural populations. Given environmental changes and socioeconomical issues in the cities, in recent years we have been experiencing an increase in the number of disease cases caused by arboviruses, which may involveCx. quinquefasciatusparticipation as a key vector. It is urgent to better understand the efficiency and susceptibility status to insecticides, as well as the genetic background of known resistant mechanisms already present inCx. quinquefasciatuspopulations for an effective and rapid chemical control when eventually required.