Insecticide resistance and target site mutations (G119S ace-1 and L1014F kdr) of Culex pipiens in Morocco

Abstract

BackgroundControl of the mosquito vector Culex pipiens with insecticides is the main way to control arboviruses that the species can transmit such as West Nile virus (WNV) and Rift Valley fever virus (RVFV). However, its efficiency has been hampered by the emergence of insecticide resistance. Little is known about the insecticide-resistance status and underlying resistance mechanisms of field-collected populations of Cx. pipiens in Morocco.MethodsMosquito adults from Mohammadia city in Morocco were reared from immature stages. The level of their susceptibility to insecticides was assessed using standard WHO bioassay. The two forms of the Cx. pipiens complex and their hybrids were identified by a multiplex PCR. Identified mosquitoes were then tested for the presence of the G119S ace-1 and L1014F kdr mutations using PCR-RFLP and PCR assays, respectively.ResultsWHO bioassays indicated that Cx. pipiens was resistant to all tested insecticides: lambda-cyhalothrin (49% mortality), permethrin (63% mortality), DDT (16% mortality), malation (52% mortality) and bendiocarb (39% mortality). The frequency of the 119S allele was almost identical in the pipiens form and hybrids (0.11 and 0.15, respectively) whereas it remained low in the molestus form (0.03). No significant correlation was observed between the G119S allele and the resistance phenotype to two tested insecticides (malathion and bendiocarb). The frequency of the L1014F allele was identical in the pipiens form and hybrids (0.44) whereas it was low in the molestus form (0.36) but no significant difference was detected (χ2 = 1.46, df = 1, P = 0.225). The presence of the L1014F kdr mutation was significantly associated with resistance to three tested insecticides in pipiens form (P = 0.0019, P = 0.0023 and P = 0.023, respectively, to lambda-cyhalothrin, permethrin and DDT) whereas no significant correlation was observed between the L1014F kdr mutation and resistance phenotype in molestus form and hybrids to the three tested insecticides.ConclusionThese findings showed that wild populations of Cx. pipiens have developed resistance against the main insecticide families with different modes of action: organochlorines (DDT), organophosphates (malathion), carbamates (bendiocarb), pyrethroids (lambda-cyhalothrin, permethrin). Therefore, urgent action should be taken to manage the resistance in this species to maintain the effectiveness of arbovirus control.

G119S ace‐1 mutation conferring insecticide resistance detected in the Culex pipiens complex in Morocco

“…32 Moreover, we also investigated whether the degree of urbanization (a proxy for the density of human populations and insecticide treatments) was correlated with resistance. This study thus completes previous ones, 30,31,33 to provide a reference assessment of insecticide resistance in the Cx. pipiens complex in Morocco.…”

Insecticide resistance and molecular characterization of knockdown resistance ( kdr ) in Culex quinquefasciatus mosquitoes in Sri Lanka

“…These observations are consistent with those reported in the world by several researchers, who reported that a high level of resistance was acquired in urban larval populations of Culex sp. after continuous treatment with organophosphates (Tmimi et al 2018).…”

Monitoring Insecticide Resistance and Target Site Mutations of L1014 Kdr And G119 Ace Alleles in Five Mosquito Populations in Korea

“…population, which presented a resistant phenotype to chlorpyriphos. Chlorpyriphos, as well as temephos and pyrimiphos-methyl, are widely used in the control of mosquito larvae [36].…”

“…This continuous and intensive exposure to insecticides is responsible for the high levels of resistance. The resistance levels are not only due to intensive prior use but also due to the acquisition of cross-resistance [36]. Sinegre et al [35] reported that in Cx.…”