关键词: 致乏库蚊, 抗药性, 杀虫剂

Abstract: This paper employed the methods of differential dosage and median lethal concentration to study the resistance levels of the 3rd instar larvae of Culex quinquefasciatus to several common insecticides in cities of Guangdong province in 1997. With the method of differential dosage, the result showed that the resistance grades of C.quinquefasciatus to Malathion, Permethrin and Deltamethrin were all high and had reached R grade in seven cities where we selected for investigation, including Guangzhou,Shenzhen,Shantou,Foshan,Shaoguang,Maoming and Jiangmeng. With the method of median lethal concentration,the result were as follows, the resistance factors (LC₅₀ of field insect/LC₅₀ of susceptible insect) of mosquitoes to Malathion were more than 5 fold in mentioned six cities except Jiangmeng, among which that was the highest and 15 fold in Guangzhou and Shenzhen; The RFs of mosquitoes to Basa and Sunside were less than 5 fold in above mentioned cities; The RFs of mosquitoes to Deltamethrin were more than 5 fold in above mentioned cities, in which that was the highest and 54.8 fold in Guangzhou, and higher and about 36 fold in Shenzhen and Shantou, and the lowest in Foshan;The RFs of mosquitoes to Cypermethrin were more than 5 fold in mentioned cities except Maoming; The RFs of mosquitoes to Permethrin were more than 5 fold in 5 cities investigated,in which that was the highest and 17.1 fold in Shenzhen; The RFs of mosquitoes to EBT were not over 5 fold in seven cities investigated. Those showed that the resistance situation of mosquitoes to Deltamethrin, Cypermethrin and Permethrin et al. were very serious in cities of Guangdong province. We should use insecticides scientifically to control mosquitoes of cities with integrated pest management.