Objective To identify the resistance of Culex pipiens pallens to five commonly used insecticides in Xianyang city so as to provide evidence for control strategy development. Methods The mortality of larvae exposed to five insecticides was determined by the distinguishing dosage method. Results The resistance level of Cx. pipiens pallens was high under the diagnosis dose to DDT, DDVP, permethrin, and deltamethrin, and the mortality in 24 hours was 23.45%, 14.02%, 28.77%, 25.00%, respectively. The resistance to cypermethrin was moderate and the mortality was 58.63%. Conclusion The resistance of Cx. pipiens pallens to five commonly used insecticides in Xianyang has reached middle to high levels. Different kinds of insecticides should be used for control of mosquitoes.

【Abstract】 Objective To study dividing line and influence factor of Aedes albopictus in Shaanxi province.  Methods Adult mosquitoes were captured by mosquito?net trap, light trap and mosq?ovitrap method.  Results Ae.albopictus distributed widely in Baoji and Hancheng city, and mainly at the special places such as worn type deposit places and junk recycle bin in Longxian and Tongchuan city. There was no Ae.albopictus in Yijun, Huangling and Yichuan. The peak of Ae.albopictus was in August in Baoji city and in September in Hancheng city. Temperature was possible the decisive factor that affected dividing line of Ae.albopictus. Conclusion The western boundary of Ae.albopictus was in Baoji city, the northern ones in Longxian, Tongchuan and Hancheng. Compared to light trap, mosquito?net trap and mosq?ovitrap method were best for the surveillance of Ae.albopictus, which would provide the ecological evidence for the control of mosquitoes.

【Abstract】 Objective To investigate the resistance of Culex tritaeniorhynchus to insecticides used frequently in high incidence areas of Japanese encephalitis in Shaanxi province. Methods The density of mosquitoes was calculated by labor hour method. Larva death rate of five insecticides and LC50 of eight insecticides were determined by distinguishing dosage method and median lethal dose method respectively. Results The average density of Cx.tritaeniorhynchus in breeding farm was 194.91/man· hour. The mortality of mosquitoes in Nanzheng, Hanyin, Hanbin and Pingli county was 1.84％-13.65％ and 10.86％-31.25％ after treatment by DDVP and deltamethrin for 24 h. Maximum LC50 of the same insecticide in different areas was1.27-8.00 times of the minimum. Conclusion Cx.tritaeniorhynchus developed different resistance to tested insecticides in four investigation sites, except that it was susceptible to cypermethrin in Hanbin, Nanzheng county and to DDT in Pingli, Nanzheng county. Cx.tritaeniorhynchus populations had developed high resistance to DDVP and deltamethrin, moderate resistance to permethrin. Rotational or mixed use of insecticides with different action mechanisms should be adopted to postpone the development of insecticide resistance.

【Abstract】 Objective To test the control efficacy of different chemicals to Culex pipiens pallens. Methods The methods of laboratory efficacy test for aerosol and simulated field efficacy test were used in this study. Results KT₅₀ values of seven aerosols to Cx.pipiens pallens was 1.30-4.40 min, and the mortality rate was about 95.0%-100% after treatment for 24 h. The knockdown rate and the mortality rate were all within 93.0%-100% after treatment in the simulated field for 1h and 24 h. The control efficacy of seven chenmicals accorded with the national standards, but there was still more significant difference among them. Conclusion The control efficacy of 0.05% tetramethrin·cypermethrin was the best, which had the characteristics of fast knockdown, high mortality and low cost.

Objective To provide scientific data for deratization by comparing the control effect of coumatetraly,brodifacoum and sodium diphacinone in the laboratory and the field.Methods Selective feeding method in single cage was used to determine the palatability of the poison baits and the control effect in the laboratory.A hennery in dingbian county and two sanitariums in the suburbs of xi'an were selected as test fields and the powder trace method was used to determine the rodent density.Results The feeding indexes to coumatetraly,brodifacoum and sodium diphacinone were 0.61,0.24 and 0.51 respectively,which reached A,B and A grade respectively.The corrected mortality in the laboratory was 100%,reaching A grade.And that in the field were 91.34%,80.94% and 88.39% respectively,which also reached A,B and B grade respectively.Conclusion Three anticoagulants had good palatability and good control effect in the laboratory.Especially,the control effect of coumatetraly was the best among three anticoagulants.

Objective To know species composition and habitats of mosquitoes in the border area of Aedes albopictus distribution area in Shaanxi province,and to evaluate effect of mosq-ovitrap and photocatalytic mosquito and fly trap.Methods Choosing 6 different habitats in three survey sites from July to September in 2006.Putting the mosq-ovitrap to observe attracted adults and larvae of Ae.albopictus,and photocatalytic mosquito and fly trap to observe attracted adults.Results Ae.albopictus was found in Baoji and Hancheng city.Average mosquito and oviposition positive index(MOI) by mosq-ovitrap was 17.92.Reproduce fastigium of Ae.albopictus was in Augest.The highest MOI of Ae.albopictus was in hilly area and woodland,was 33.20.Total 925 mosquitoes were collected in three survey sites by photocatalytic mosquito and fly trap.8 species of 5 genera were recongnized. Culex pipiens pallens was the dominant species.It was 76.11% of the total. Cx.pipiens pallens, Armigeres subalbatus and Cx.tritaeniorhynchus distribute in all habitats investigated. Cx.tritaeniorhynchus is more in the area of breeding and cultivation.Conclusion The distribution of Ae.albopictus is same as history data. Cx.pipiens pallens, Cx.tritaeniorhynchus and Ar.subalbatus are dominant populations in this area.The mosq-ovitrap and photocatalytic mosquito and fly trap have a high attractive effect.

Objective To investigate the community structure of mesquitoes and their ecological distribution at Hancheng city in 2006,and to evaluate efficacy of the mosq-ovitrap for monitoring Aedes albopictics in the field.Methods Using human baited net trap,light trap and mosq-ovitrap method for adults,and container method for larvae investigation.Results Mosquitoes collected from Hancheng city belonged to 5 genera 7 species,Human were attacked mainly by Ae.albopictus, Culex pipiens pallens, Armigeres subalbatus, Culex tritaeniorhynchus.The positive container index of larvae investigation was 34.38.The density of adults by human baited net trap method was 7.16 individuals per hour,1.13 individuals per hour by light trap method.The positive mosquito index of mosq-ovitrap was 15.32% in the field,the average amount of adults were 1.37 per trap,and the oviposition index by mosq-ovitrap was 14.41%.The positive mosquito index in September was higher than that in others and was 18.25%.The oviposition index was also the highest in September and was 21.25%.The oviposition index by mosq-ovitrap was higher than that by white paper cups( χ ²=45.14, P<0.001).The density of adults was the highest at the special places(worn type deposit places,junk recycle bin,and so on),and in the village was higher than in the urban,in the area for rest and recreation was higher than in cultivition area.The positive container index of larvae at the village was higher than at the urban,in the area for rest and recreation was higher than in cultivition area.Conclusion Ae.albopictus, Cx.pipiens pallens, Ar.subalbatus and Cx.tritaeniorhynchus were dominant population attacking human in this area.The mosq-ovitrap had a high attractive effect to Ae.albopictus adults and eggs.It can be applied for monitoring Ae.albopictus.The investigation provided some basic information for controling mosquitoes.