Objective To investigate the efficacy of three mosquito attractants (Attractant A, B, and C), carbon dioxide (CO ₂) at different flow rates and attractant combined with CO ₂in attracting Aedes albopictus, to screen out the optimal combination, and to provide a scientific basis for the application of chemical pheromone monitor in the field work of Ae. albopictus surveillance. Methods A remote-controlled chemical pheromone mosquito trap monitor was used to perform the trapping test. A total of 200 Ae. albopictus mosquitoes were placed in the simulation room, and the trapping test was conducted for the three mosquito attractants, CO ₂ at different flow rates, and attractant combined with CO ₂, and efficacy was observed after 24 hours. The Chi-square test and the logistic regression analysis were used to compare and analyze the efficacy of different attractants and CO ₂ flow rates in trapping Ae. albopictus. Results CO ₂ at a flow rate of 80, 150, and 200 ml/min had mean trapping rates of 50.42%, 64.67%, and 74.33%, respectively, and attractant A, B, and C had mean trapping rates of 66.40%, 70.30%, and 53.00%, respectively. Attractant A combined with CO ₂ at a flow rate of 80, 150, and 200 ml/min had mean trapping rates of 66.67%, 67.33%, and 79.67%, respectively, and attractant B combined with CO ₂ at a flow rate of 80, 150, and 200 ml/min had mean trapping rates of 70.67%, 78.67%, and 82.33%, respectively. Conclusion In the simulation test, the remote-controlled chemical pheromone mosquito trap monitor with the application of mosquito attractant and CO ₂ has a marked effect in trapping Ae. albopictus, which is better than the use of attractant or CO ₂ alone. The surveillance method can be used for field surveillance and control of vector Aedes mosquitoes.

Objective To investigate the interspecific competition between Aedes aegypti from Wushi town of Leizhou and Ae. albopictus from different places in Guangdong province, China, and to evaluate the dispersal ability of Ae. aegypti. Methods From March to August 2017, 100 second-instar larvae of Ae. aegypti from Wushi town and 100 second-instar larvae of Ae. albopictus from one of selected places in Guangdong province were mixed and raised in a mosquito room. Eighteen days after emergence, all adult mosquitoes were collected with an electric mosquito vacuum for classification and counting, and all mosquito eggs were collected and put in water for next-generation rearing. A total of six generations of mixed rearing were conducted to compare the competitiveness of different species by the number. Results In each generation, Ae. aegypti was the first to emerge, and Ae. albopictus emerged more than three days later. The number of Ae. aegypti from Wushi town of Leizhou was more than the average number of Ae. albopictus in this town and the number of Ae. albopictus from Meizhou in each generation; there were five generations more than that from Maoming, one generation less; there were four generations more than that from Qishui town of Leizhou, Shaoguan and Shenzhen, two generations less; there were two generations more than that from Zhanjiang, four generations less; there was one generation more than that from Guangzhou, five generations less. Conclusion Aedes aegypti from Wushi town of Leizhou has strong competitiveness against Ae. albopictus from Meizhou, Maoming, Shaoguan, and Shenzhen of Guangdong province.

Objective To investigate the mosquito infestation in the mouths of manholes under the municipal administration networks in Shenzhen, Guangdong province, China, and to provide a basis for the prevention and control of mosquito-borne diseases in urban areas. Methods The ponding status, mosquito infestation rate, and mosquito density were investigated in the mouths of manholes under the municipal administration networks of representative subdistricts in the new town areas, old town areas, and urban villages in Shenzhen. The larvae were captured with a 500-ml larva sampling spoon for density (larvae/spoon) calculation. Results A total of 508 mouths of manholes under the municipal administration networks were investigated in November 2017; the mean positive rate of mosquito infestation was 4.7% (including a mean positive rate of Aedes infestation of 3.3%). The mounting rate and maintenance rate of Mosquito Proof Set (the four types of mosquito proof facilities, including mosquito repellent sticks, mosquito proof sluices and nets) were 27.4% and 76.3%, respectively. Of the mouths of positive manholes, 83.3% were not equipped with Mosquito Proof Set. The highest and lowest densities of larvae in the positive manholes were 43 larvae/spoon and 1 larva/spoon, respectively. Relatively high positive rates were observed in water supply manholes (5.9%), sediment manholes (5.7%), and municipal sewage manholes (5.5%). The sediment manholes, municipal sewage manholes, and municipal rainwater manholes had a relatively high constituent ratio both in the overall manholes investigated (84.8%) and in the positive manholes (87.5%). No mosquito infestation was found in the mouths of gas, communication, and power supply manholes. Conclusion The Mosquito Proof Sets are conducive to reducing mosquito infestation in the sewers. Places most seriously infested with mosquitoes are sediment manholes, municipal sewage manholes, and municipal rainwater manholes under the municipal administration networks. The Mosquito Proof Sets can effectively reduce mosquito infestation.

Objective To understand the seasonal variation in the population density of Aedes albopictus in Guangdong province, China, based on a standard surveillance method, and to provide a scientific basis for the early warning and prediction for Aedes-borne diseases. Methods From 2007 to 2017, the population density of Ae. albopictus in Guangdong province was monitored by Breteau index (BI), mosquito ovi trap index (MOI), and the mosquito light trap method. Results The Ae. albopictus larvae density surveillance in 9 506 102 houses resulted in a mean BI value of 2.94. The adult Ae. albopictus density surveillance using 1 428 078 effective mosquito ovitraps resulted in a mean MOI value of 4.98. The adult Ae. albopictus density surveillance using 82 019 effective mosquito light traps resulted in an overall Ae. albopictus density of 0.21 mosquito/lamp·night. Between-group comparison made by analysis of variance and the Bonferroni method showed that there was a significant difference in BI surveillance results between different environments ( F=69.158, P<0.01). However, there were no significant differences in MOI or mosquito light trap surveillance results between different environments ( F=1.642, P=0.174; F=1.973, P=0.081). According to the surveillance results by the three methods, the population density of Ae. albopictus was higher in summer and autumn than in winter and spring. Conclusion Aedes albopictus exists all the time of a year in Guangdong province. The population density of Ae. albopictus varies with year, and season. Therefore, the prevention and control of Ae. albopictus should be performed on a case-by-case basis. The sensitivity of a surveillance method varies with environment, suggesting that the selection of surveillance methods should depend on the surveillance environment.

Objective To study the efficacy for mosquito control and residual effect of different pesticides by artificial simulation as barrier spray on vegetation. Methods Using insecticidal barrier spray on vegetation technology, Scheffleraoctophylla were sprayed separately by 2.5% effective chloric fluorine with ester millirod suspending agent (Demand), 10% alpha-cypermethrin (Fendona) and 10.4% chlorine chrysanthemum-allyl chrysanthemum water emulsion (alpha-cypermethrin). Then they were moved to an outdoor tent. A total of 30 female Aedes albopictus were put into every tent weekly. One rat and four mosquito oviposition device were introduced into every tent after 24 h, then collected mosquito eggs after 3 d, and recorded survived mosquitoes. Results 2.5% effective chloric fluorine with ester millirod suspending agent remained effective for more than 21 weeks, 10% alpha-cypermethrin for 9 weeks, and 10.4% chlorine chrysanthemum-allyl chrysanthemum water emulsion had no residual effect. The maximum of weekly counts for survivors was 4, 15 and 21 respectively. The median was 1, 5 and 7. Conclusion Both 2.5% effective chloric fluorine with ester millirod suspending agent and 10% alpha-cypermethrin have good mosquito killing and residual effect by using insecticidal barrier spray on vegetation, 2.5% effective chloric fluorine with ester millirod even better.

Objective Application of insecticidal barrier spray on vegetation for dengue mosquito vector control to explore rapid and long-term effective control means for dengue mosquito vector control in the urban communities. Methods From June to September of 2015, the phoenix garden of Shaoguan city in Guangdong province was selected as the test site, comparing the effectiveness of barrier spray on vegetation technology to kill the dengue vector mosquito with the ultra low volume spraying. Results The insecticidal barrier spray on vegetation showed quick kill effect, and continuous control effect on Aedes albopictus, reducing mosquito lure egg apparatus index (MOI) lure under 5 for 2 to 4 weeks, the duration of the MOI under 10 for 3 to 6 weeks, the duration of the effective control of mosquito density for 6 to 7 weeks. Pesticide resistance was not detected. Conclusion Insecticidal barrier spray on vegetation can effectively control dengue mosquito vector density more than one month. Compared with ultra-low volume spraying, insecticidal barrier spray on vegetation reduced the cost by 37.50%, saved on-site manpower, pesticides and time, had a positive impact on dengue fever outbreak control in urban communities.

Objective To investigate the resistance status of Aedes albopictus to used insecticides in the late stage of dengue fever emergency control of Guangdong province in 2014, and learn how to prevent the development of resistance. Methods From the end of October to the beginning of November 2014, larve of Ae. albopictus were collected in epidemic regions in Haizhu and Baiyun district of Guangzhou city, Chancheng and Nanhai district of Foshan city, Chaoyang district of Shantou city, Chao'an district of Chaozhou and Rongcheng district of Jieyang city, and were reared about 1 to 2 generations in the lab, then were tested along with the susceptible larvae according to the methods of national standard “Test Methods of mosquito resistance to insecticides-bioassay methods”(GB/T 26347-2010) to calculate LC₅₀ and resistance index. Results Aedes albopictus of all tested regions had low resistance to temephos and propoxur, the resistant index was 4.92-8.33 and 2.35-6.23 fold respectively. The resistantce to permethrin, beta cypermethrin, deltamethrin resistance were 3.53-31.29 fold, 8.35-38.69 fold, and 2.63-37.04 fold respectively. Of pyrethroid insecticides, Guangzhou city have reached the high level resistance mostly, Foshan city, Chaozhou city mostly low level of resistance, Jieyang city for low level of resistance, Shantou city mostly above the moderate level of resistance against cypermethrin. Aedes albopictus from some cities also have developed resistance to other insecticides in different levels. Conclusion Resistance of Ae. albopictus in the dengue epidemic cities in Guangdong increased very quick to the used insecticides. The control of Ae. albopictus should adhere to the principle of sustainable and integrated management to prevent or delay the development of resistance.

Objective To study the community structure, dynamic and West Nile virus (WNV) carried of mosquito vectors in Guangdong, and provide scientific evidence for further development of control and prevention strategies. Methods Mosquito density was monitored by Light-trap from May 2013 to April 2014. One-step reverse-transcript PCR was applied. Results The average density of mosquito was 11.80/light. The seasonal peak of density was from May to July. Of all habitats the density in the barn was the highest. Culex pipiens quinquefasciatus accounts for 89.90%, the largest proportion of mosquitoes. No positive was found by RT-PCR. Conclusion Culex pipiens quinquefasciatus was the predominant species, the monitoring data could provide scientific basis for the control strategies and warning and forecasting of WNV, but the vectors species of West Nile fever in Guangdong province and its spread risk needs to be further studied.

Objective To investigate the resistance levels of Musca domestica to four commonly used insecticides in the special places such as landfill and meat processing plant in Guangdong province, China. Methods M. domestica larvae were collected in the wild breeding habitats, and topical application was used to determine the median lethal doses (LD₅₀) of permethrin, deltamethrin, beta-cypermethrin, and DDVP for M. domestica. The experimental data were statistically analyzed by extremum method. Results The LD50 of permethrin, deltamethrin, beta-cypermethrin, and DDVP were 13.7179, 3.5971, 5.5982, and 0.7704 μg/insect, respectively, for M. domestica in the landfill and were 1.0999, 0.7278, 8.3314, and 0.5322 μg/insect, respectively, for M. domestica in the meat processing plant. The resistance ratios were 58-2525, increased 1-103 times compared with those in 1996 and increased 2-1383 times compared with those in 1991. The resistance of M. domestica to permethrin, deltamethrin, and DDVP was higher in the landfill than in the meat processing plant. Conclusion M. domestica develops high resistance to some insecticides in the special places in Guangdong province, and the resistance to pyrethroid increases rapidly. Comprehensive management strategies and proper insecticide use should be adopted to control M. domestica in the special places such as landfill and meat processing plant.

Objective To analyze the association between prevalence of Chikungunya fever and Mosq-ovitrap index (MOI) and to investigate the infection with Chikungunya virus (CHIKV) in larval and adult Aedes albopictus. Methods Mosquitoes were collected by mosq-ovitrap and the mosquito density was also determined by Breteau index (BI) during Chikungunya fever outbreak. CHIKV was detected in the Ae. albopictus samples collected in the field by real-time fluorescence PCR and cell culture for isolation. Results Comprehensive emergency control measures were taken for anti-mosquito purpose after the confirmation of Chikungunya fever outbreak. After one week of ergency management, the epidemic situation was effectively controlled, as shown by the fact that both MOI and BI were lower than 5. The collected mosquito samples were divided into 27 groups according to collection time and location, and then CHIKV detection was performed. The results showed that all adult mosquito samples were virus negative, and 3 larval mosquito samples soaked in alcohol were questionably positive, counting for 12.5% of all 24 larval mosquito samples. There were only negative results in the virus detection based on cell culture and isolation. A total of 253 cases were reported in the community with Chikungunya fever outbreak, and the emergency control measures lasted for 22 days. Conclusion As for responding to Chikungunya fever outbreak, mosq-ovitrap is safe, effective, and easy-to-operate for indicating emergency mosquito control, especially for evaluating control efficacy and detecting virus in adult mosquitoes. The infection rate and transmission rate of CHIKV in Ae. albopictus during Chikungunya fever outbreak deserve further study in the future.

Objective To determine the characteristics and dynamics of mosquito population during the process of rapid urbanization, and to identify the relationships between the dynamic of main vectors and rapid urbanization. Methods The mosquito density was investigated for the past four years using the human-bait method. Results Five species of mosquito were captured, including Culex tritaeniorhynchus, Culex pipiens quinquefasciatus, Anopheles sinensis, Aedes albopictus, and Armigeres subalbatus. Cx. pipiens quinquefasciatus was predominant (92.27%), followed by Ar. subalbatus (3.98%). The proportions of Ae. albopictus and Cx. tritaeniorhynchus were relatively small, accounting for 1.62% each. The smallest was An. sinensis (0.51%). During a four-year study period, significant changes had taken place in the proportions of mosquito populations by comparison among the data in 2006, 2008 and 2009. The population of Cx. pipiens quinquefasciatus decreased while increased of that of Ae. albopictus. An. sinensis gradually disappeared as the time elapsed. The poplation of Cx. tritaeniorhynchus fluctuated largely in the study periods. In the evening, varieties of mosquito species showed distinct activity patterns. The biting time of Cx. pipiens quinquefasciatus and Cx. tritaeniorhynchus was from 19: 00 to 22: 00 in the evening with a peak after 21: 00. Ae. albopictus could be caught all the night with the main peak before 20: 00. A similar activity pattern was observed from Ar. subalbatus and Ae. albopictus. Conclusion During the process of rapid urbanization, the population of the dengue vector, Ae. albopictus, increased gradually. The population of the Japanese encephalitis vector, Cx. tritaeniorhynchus, fluctuated greatly in different years. However, the malaria vector, An. sinensis, eventually was not found. Thus, we propose that the surveillance and control of Ae. albopictus and Cx. tritaeniorhynchus should be strengthened during the process of urbanization.

【Abstract】 Objective To test the efficacy of four kinds of electric liquid repellents (A 0.12% dimefluthrin, B 0.17% dimefluthrin, C 0.86% transfluthrin, D 0.86% prallethrin) for the Japanese encephalitis(JE) vectors in the field. Methods The landing count method was used to the investigation of mosquito density before and after treatment by electric liquid repellent. Results The main species caught in the field were Culex pipiens quinquefasciatus and Cx. tritaeniorhynchus, which were the JE vector. Only  sample  A  reached ＞80%  population  reduction  of  Cx. tritaeniorhynchus. Both sample B, C and D caused ＜80% population reduction of Cx. tritaeniorhynchus. Both sample A, C and D caused ＞80% population reduction. However, only sample B led to 70%-80% population reduction. Conclusion The tests suggest that four samples have a good repellent effect on mosquito, but the efficacy of sample B is less than that of sample A, C and D. There are different for the control efficacy of different electric liquid repellent in the lab and the field.

【Abstract】 Objective To study the resistance of Rattus rattus sladeni to anticoagulant rodenticide. Methods No?choice food test was used in this study according to the method of national rodent resistance surveillance group. Results The rodents caught in nine districts of Guangzhou were tested. The survival rate  was 3.8%. The total average dosage was 30.31 mg/kg, and survival  average dosage  was  58.29 mg/kg.  The  result  showed  that  its  sensitivity  to  anticoagulant   rodenticide  was  between R.tanezumi and  R.norvegicus.  Conclusion The  anticoagulant  rodenticide can be still used to the control of R.rattus sladeni. But it should strengthen the resistance surveillance, and the chemicals should be used scientifically and rationally. 

【Abstract】 Objective To develop a system of stepwise response for risk categories for dengue fever in China. Methods According to ecological features of Aedes albopictus, establish the method of mosquito and oviposition trap and compare the relationship of the mosquito and oviposition positive index （MOI） and the Breteau index （BI） or the Ovitrap index obtained from the traditional dengue fever vectors surveillance. Develop an epidemic forecast and phased response system for dengue fever control and prevention with reference to other correlative grade control system for dengue or other vector?borne disease, combined with the actual application of mosquito and oviposition trap in the vector surveillance. Results The MOI could be classified into 4 levels, below 5, 5-20, 20-40, and ＞40 respectively. Stepwise response for risk categories for dengue fever were divided into 4 levels according to the levels of MOI, seasonal character, virus infection rates in mosquitoes and the result of human cases surveillance. Conclusion The MOI is less than 5, which suggestes the control of dengue fever is very effective. However, the risk categories and its response index still need further study and verify in the practical application.

【Abstract】 Objective A field study was carried out in a restaurant in the south of China to investigate the blood sources affected Japanese encephalitis （JE） vectors Culex tritaeniorhynchus and Cx.pipiens quinquefasciatus indoor abundance. Methods Vector density was investigated by human?leg capture technique. Results In the dinning room adjacent to deer blood resource, Cx.tritaeniorhynchus was the dominant specie（74.80% of total number） and the minor vector was Cx.pipiens quinquefasciatus （21.14%）. However, in the restroom where the mosquitoes could only access to human blood,  Cx.pipiens quinquefasciatus accounted for 60.28% and that of Cx.tritaeniorhynchus was 36.62%（n＝845）. The density of Cx.tritaeniorhynchus in restroom was higher than that in the dinning room （df＝1, χ2＝5.32，P＜0.05, n＝676）. However, the density of Cx.pipiens quinquefasciatus in the dinning room was higher than that in the restroom（df＝1, χ2＝268.45， P＜0.001, n＝611）. Conclusion The results showed that the blood resources influenced the JE vector spatial abundance. The abundance of Cx.tritaeniorhynchus or Cx.pipiens quinquefasciatus was affected by the animal blood or the human blood.

Objective To investigate the breeding characteristics of Aedes albopictus in urbanization residential area,which should provide the basis for the control of Ae.albopictus. Methods The study was carried out in the village of Jieyang city and high-urbanization downtown of Foshan from March 2004 to November 2005. Water containers were detected in and around one household which was randomly selected every 5 households. The data were analyzed by software SPSS 11.0. Results Of 5635 possible breeding sites in 7470 houses investigated, 502(6.72%) were positive. In the village of Jieyang,the major breeding containers included unused container (jars, bottles and tins, etc.) and water reservoir receptacles with the positive constitute ratio of 64.98% and 18.77% respectively. The positive constitute ratio of unused containers reached the maximum in September every year. But in residential area of Foshan city, the major breeding containers were made up of water vases in which the flowers and plants grow and unused containera, and the positive constitute ratio of them were 45.52% and 33.79% respectively. The positive constitute ratio of unused containers was in the peak from July to September, and that in miniascape and water plant was the highest in 2004 and May 2005 with the value of 75.00%. But the result was zero after May 2005. Conclusion There were different among the breeding sites in different residential area, which varied with season. The breeding containers in increasing urbanization cities were mainly miniascape, water plant and unused containers, but in low urbanization village, the breeding sites were mainly the unused containers and water reservoir receptacle.

Objective To study the sensitive of TaqMan MGB Real-time polymerase chain reaction(PCR) and nested RT-PCR on detecting Dengue virus(DV) from Aedes albopictus and establish a sensitive, specific, and repetitive method for DV diagnosis. Methods Females adults were artificially infected with Den-2 in lab, different infected mosquito concentration (mosquitos/1000 μl) and 50 mosquitos/pool were designed and processed for virus detection by TaqMan MGB Real-time PCR and nested RT-PCR. Fluorescence signal and electrophoresis showed the results. Results For all pool, the lightest concentration that can be detected was 3 mosquitos/1000 μl for two-step TaqMan MGB Real-time PCR, and 5 mosquitos/1000 μl for one-step TaqMan MGB Real-time PCR and nested RT-PCR. Conclusion Two-step TaqMan MGB is more sensitive, specific, scientific and rapid to detect DV than nested RT-PCR, and is a good surveillance method for DV in A.albopictus.

Objective In order to test the efficacy of four kinds of mosquito coils in the field,and to investigate the efficacy tests and evaluation methods for different kinds of mosquito coils.Methods Compare with density reduction by the bite counts based on pre-and post-treatment using human-leg catch technique.Results The main species which was caught in the trial field was Culex pipiens quinquefasciatus and decreased the peak of bites period was from 22:00 to 23:00 in the evening.Coil A and D caused 88.2%,90.5% population,respectively.However,coil B and C led 72.5%,78.1% population reduction,respectively.Conclusion The tests suggested that four coils had a good effect on prevention from the bites of the mosquito,yet,the insecticide efficacies of coil A and D are better than that of coil B and C.Discussion: Pre-trial is very essential for the efficacy tests in the field trial.Simulating field test for indoor insecticidal efficacy should be adopted to correct or reduce the experiment error.

Objective To compare the results and understand relationship between the mosq-ovitrap method and larval survey for detecting the presence of ; Aedes mosquitoes in the field. Methods The study was carried out in the cities of Foshan and Jieyang,Guangdong province,from March 2004 to November 2005. A mosq-ovitrap was set every 5 random households and their premises,or set every 25-50 meters in a hidden and shady place in the surroundings of hospitals,schools,government office buildings,factories and gardens. Larval surveys and mosq-ovitrap method were used simultaneously in the households or in the areas of 5 meters around the trap set in the surroundings. Results In households,hospitals,schools,government office buildings,factories and gardens,14 902 mosq-ovitraps were simultaneously set and 14 648 were collected back. The positive traps for adult mosquitoes was 932. The mosquito and oviposition positive index(MOI) and mosquito-trap density index(MDI) were 6.36 and 1.03± 0.89 respectively. Total 962 Aedes albopictus(99.5)and 5 Culex(0.5) were collected. The maximum of the mosquito adults captured in a single trap was 10. At the same time,8537 water containers in 14 902 households or premises (5 meters in circumference of the mosq-ovitrap) were checked,of which 844 contained the Aedes albopictus larvae. The Breteau Index,House Index and Container Index were 5.66 ,3.87 and 9.89 respectively. The MOI was 1.12 times of the Breteau Index,or 1.64 times of the House Index,or 0.64 times of the Container Index. Conclusion There is a positive relationship between the MOI and the Breteau Index,and the House Index,the container Index respectively. The MOI is particularly approximate to the Breteau Index.

Objective To compare the results between the mosq-ovitrap and the Ovitrap in the field. Methods The trial was carried out in a campus in Guangzhou from August to November 2004,and from February to August 2005. One mosq-ovitraps and one ovitraps at intervals of 1 m were set every 50 m at hidden and shady spot and the positions of two kinds traps were alternated each month. Mosquitoes captured and the egg positive traps were counted and recorded on the 4 ^th day and the 7 ^th day since the installation. Results On the 4 ^th day since installation,the positive indices of mosq-ovitrap and ovitrap were 35.5 and 56.7 respectively; and at 7 ^th days,the positive indices were 53.3 and 71.5 respectively. In total,the oviposition index(OI) of the ovitraps at 7 ^th days was nearly 2 times of the mosquito and oviposition positive index(MOI) of mosq-ovitraps installed for 4 days. 284( 99.3 ) Aedes albopictus,and 2 Culex quinquefasciatus were captured in the 662 mosq-ovitraps installed for 4 days . The mosquito(Aedes)-trap density index(MDI) was 1.21± 1.12 ,the number of caught mosquitoes ranged from 0 to 8 in all the mosq-ovitraps. The results of the surveillance in each month indicated that there was positive correlation between the MOIs of the mosq-ovitraps set for 4 days and the OIs of the ovitraps set for 7 days ( r=0.838 , P=0.001, y=25.548+1.312 x). Conclusion When the mosq-ovitraps were applied for 4 days,the MOI could reflect the population seasonal dynamic of mosquito. There was positive correlation between the MOIs of the mosq-ovitraps and the OIs of the ovitraps.

Objective To study the resistance development of anticoagulant rodenticide in commensal rodents. Methods Tests was carried out without selectivity by rodents based on the method of National Rodenticide Resistance Monitoring Co-worker Group. Results 769 Rattus flavipectus and 303 Rattus norvegicus were caught in five cities of Guangdong were tested. The resistance rate differs from 1.69 to 12.21 the average dosage taken differs from 10.36 mg/kg to 131.96 mg/kg . The result showed that Rattus flavipectus and Rattus norvegicus had become individual resistance to the resistance rodenticide Ⅰ. Conclusion The anticoagulant rodenticide Ⅱ should be used in the areas gathered with Rattus flavipectus. The anticoagulant rodenticide Ⅰ can be still used but should be used scientifically and properly with careful tests of sensitivity.

Objective To survey the resistance status of Aedes albopictus to several commonly used insecticides in Guangdong province,and learn how to prevent the occurrence and development of resistance. Methods Larvae of Ae.albopictus were collected in five cities located in the east,south,west,north and middle of Guangdong province,and were bred for 1 to 2 generations in the lab,then tested with WHO standard bioassay to calculate LC ₅₀ and resistance index. Results Ae.albopictus had low resistance to deltamethrin and cypermethrin,the resistant index was 3.10-4.20 against deltamethrin,and 2.23-2.91 against cypermethrin. Ae.albopictus was sensitivity to malathion,and the index is 1.05-1.91. Ae.albopictus from some cities also had developed resistance to other insecticides in different levels. Conclusion Resistance should be monitored regularly. Insecticides should be used scientifically and rationally to prevent and reduce the occurrence and development of resistance.

Objective To study the sensitivity of TaqMan MGB Real-time Polymerase Chain Reaction (PCR) on detecting Dengue virus (DV) from Aedes albopictus and to develop a sensitive,specific,and repetitive assay method for DV diagnosis. Methods Females A.albopictus were artificially infected with Den-2 in lab,different concentration for infecting mosquito (mosquitos/ 500 μl or mosquitoes/ 1 000 μl) and different pools (0,10,25,50 females of lab A.albopictus without DV were added to each treatment) were designed to process of virus detection by one-step and two-step TaqMan MGB Real-time PCR. Fluorescent signal was observed to show the results. Results For all pools,the minimal concentration which could be detected was 2 mosquitoes/ 500 μl and 3 mosquitoes/ 1 000 μl for two-step TaqMan MGB Real-time PCR,but 5 mosquitoes/ 500 μl for one-step TaqMan MGB Real-time PCR. There was no evident effect on the detection of DV RNA by the RNA of A.albopictus. Conclusion TaqMan MGB is sensitive and specific to detect DV,and is a perfect surveillance method for DV index of A.albopictus. It is better for 20-30 mosquitoes/pool and 500 μl dilution/pool by two-step TaqMan MGB Real-time PCR.

Objective To learn the morphological characteristics of red fire ant in Wuchuan,Guangdong and compare the characteristics with those in other countries. Methods Both field survey and lab investigation were used to study the stages of the red fire ant and nest figure. Results The morphological characteristics of egg,larva,pupa and adult of the ant were given. Diagnostic characterisitics of adult were described. A mature nest is alveolate,and form big mound with (26.00±7.42) cm high,and (82.00±41.04) cm diameter on average of thirty random samples. which size far excess of other ants'. Conclusion There are many same morphological characteristics between red fire ant in Wuchuan,Guangdong and introduced Solenopsis invicta.

Objective To study the Interspecific relationship between Aedes albopictus and Aedes albopictus.Methods To culture the two mixed species of 100 4-star larva respectively(F ₀) in the temperature 25- 28 ℃,RH 65%- 80%,and photoperiod(L∶D) 12∶12 condition,then to observe about 1 000 imago collected by electric mosquito collector at different time.Results The population of Aedes albopictus was larger than Aedes albopictus in every generation,and larger with increasing of generation.In second filial generation(P ₂),there was no Aedes aegypti being observed in the mixed population.Conclusion Severe interspecific competition was founded in the experiment,and Aedes albopictus is more competitive in the laboratory.

Objective To investigate SARS virus carried by murine-like animals in the hygienic units to provide evidence for looking for the origin and infectious ways of SARS virus.Methods Rats were caught in usual ways.Nested RT-PCR,Fluorescent quantitative PCR,Sequence analysis and virus isolation were applied.Results There are 59 murine-like animals of three species caught in the hygienic units related to SARS in Guangzhou.32 samples of anus swabs test were tested in nested RT-PCR.The resnlts showed that four samples were positive.The positive rate was 12.5 percent.The sequence of positive parts had 90%～96% homogeneity with SARS-CoV.The result of the cell cultivation on positive samples of PCR amplification parts was negative.Conclusion It would be studied further to conform whether murine-like animals can carry and transmit SARS coronavirus.

Objective To investigate SARS coronavirus carried by or reserved in rat and cockroach,and try to provide the evidence for the origin and control of SARS coronavirus.Methods Nested reverse-transcript PCR and fluorescent quantitative reverse-transcript PCR were applied.Results With SARS Cov.-specific primer,a total of 160 rat lung tissues and 15 cockroach surface swabs were tested in nested RT-PCR and fluorescent quantitative RT-PCR.No positive was found by fluorescent quantitative RT-PCR,and only one uncertain positive result of cockroach surface by nested RT-PCR.Conclusion Nested RT-PCR and fluorescent quantitative RT-PCR are available in fast testing positive vector,and there was no evidence to regard the role of rat and cockroach in the origin and transmission of SARS coronavirus,which deserves to be studied further in the future.