Objective The efficacy of spinosad Natular G30 against Culex pipiens quinquefasciatus was evaluated at differentdoses with comparing sewage habitat and small body of water with waste plants habitat,so as to provide evidence for mosquitocontrol.MethodsUsing wild Cx. pipiens quinquefasciatus larvae and water in sewage and small body of water in Haikou,Hainan province, the efficacy of Natular G30 at 10, 20, 40, 80 mg/L was tested, percentage reduction was taken as efficacy index.The pH, temperature, total solids, salinity, dissolved oxygen of habitat water were determined at any two points of time during thetrial period.ResultsThere were significant differences(P0.05) between pH and dissolved oxygen in the two habitats, whileno differences between temperature, total solids, salinity. The pH and dissolved oxygen of sewage water were(9.62±0.43) and(12.79±3.01) mg/L, and those in small body of water with wasted plants were(8.91±0.39) and(7.77±3.46) mg/L. The residualefficacy of Natular G30 at 10 mg/m2and 20 mg/m2against Cx. pipiens quinquefasciatus in sewage breeding site lasted for 12 days,while 40 mg/m2and 80 mg/m2in both habitats was more than 30 days. In two tested habitats, after one day of Natular G30 using,the first and second instar mosquito reduction was nearly 100%, but for the third and forth instar larvae, 100% reduction date wasat three to seven days. To our surprise, the reduction of pupae was negative after one day insecticide applied.ConclusionSpinosad has high and long-lasting efficiency against Cx. pipiens quinquefasciatus larvae. Its effectiveness is better when appliedin the habitats of small body of water with wasted plants than that of sewage. Spinosad has a very higher efficacy to control thefirst and second instar young larvae than the third and forth instars larvae, but no noticeable effect on pupae. To controlCx. pipiens quinquefasciatus, the spinosad rate should be adjusted based on the characteristics of habitat water.

目的了解广东省湛江市白纹伊蚊野外种群对溴氰菊酯抗性水平和多功能氧化酶（MFO）、非特异性酯酶（NSE）、谷胱甘肽转移酶（GSTs）的活力水平及动态特征,为该地区白纹伊蚊控制及抗药性治理提供依据。方法以实验室品系为参考,采用WHO推荐的成蚊接触筒法,测定白纹伊蚊对溴氰菊酯的抗药性,同时用酶标仪测定酶活力;SPSS20.0软件分析比较种群间酶活力水平、酶活力的频率分布、变异性、酶活力与蛋白质含量的关系等。结果广东省湛江市白纹伊蚊已经对溴氰菊酯产生高抗性;其成蚊的MFO、NSE和GST酶活力分别为实验室参考品系的1.67、1.91和1.96倍,且两种群间3种代谢酶差异有统计学意义（P＜0.05）。该野外种群3种代谢酶的活力分布均呈正偏态分布,GST抗性为主要机制,抗性个体高达72.73%,其次为NSE,抗性个体占59.76%,另外还存在2种或3种酶活力同时增高的抗性个体。结论白纹伊蚊湛江种群成蚊对溴氰菊酯的高抗性,可能与3种代谢酶尤其是GST活力增强有关;应加强该地区白纹伊蚊溴氰菊酯等拟除虫菊酯类杀虫剂的抗性监测与机制研究工作,制定切实可行的抗性治理策略。

Objective To investigate the susceptibility and resistance of larvae and adult of Culex tritaeniorhynchus in Licheng district,Shandong province to the commonly used insecticides,providing the basis for chemical control of the insects.Methods A large number of adult Cx.tritaeniorhynchus were collected outdoors in the peak seasons.The first filial generation of larvae was obtained by feeding the collected adults with blood from mice.The larvae obtained and the adult female mosquitoes,which had been captured in the field and had laid the first eggs in the lab,were used as test insects.The susceptibility of the adult and larvae to commonly used insecticides were determined with the drug membrane contact method and the impregnation method respectively,as the WHO protocol,with the knockdown rate and mortality of the adult mosquitoes and the LC50(95%CI) for the larvae calculated and their resistance levels to commonly used insecticides compared.Results The mortality of the adult exposed to 0.05% deltamethrin(contact for 1 h),0.05% beta-cypermethrin(1 h),0.25% permethrin(3 h),0.45% permethrin(3 h),0.05% cypermethrin(1 h),0.45% tetramethrin(1 h),1% fenitrothion(2 h),0.1% propoxur(2 h) and 4%DDT(4 h) beyond 24 h were 85.0%,74.6%,38.0%,92.9%,36.2%,43.6%,16.1%,16.9% and 36.4%,respectively.The LC50 and the corresponding 95%CI of deltamethrin,beta-cypermethrin,and permethrin for Cx.tritaeniorhynchus larvae were 0.0046(0.0037-0.0055),0.0113(0.0092-0.0136),0.0325(0.0289-0.0369) mg/L,respectively;the LC50(95%CI) of dichlorvos,temephos,fenitrothion and malathion and BPMC were 4.9047(3.8612-6.4215),9.5733(7.4644-12.5296),1.2694(1.0280-1.5055),0.7750(0.6060-0.9842) and 4.4237(3.7406-5.2769) mg/L,respectively.Compared to the susceptible strains reported in previous literature,the resistance coefficients of the larvae of Cx.tritaeniorhynchus were 11.5,1.9 and 8.8 to deltamethrin,beta-cypermethrin and permethrin,respectively,and 76.6,7977.8,256.4 and 84.2 to dichlorvos,temephos,fenitrothion and malathion,respectively.Conclusion Adult Cx.tritaeniorhynchus in Licheng district has developed resistance to the commonly used insecticides,with a very high resistance seen to organophosphate and carbamate pesticides in the adult.The resistance of larvae to temephos is highest among the organophosphates.