Objective To investigate the changes in the water loss rate and palatability of cockroach-killing gel baits at different time after application. Methods Three commercially available common gel baits were selected: gel bait P (effective constituent: 2.15% imidacloprid), gel bait W (0.5% dinotefuran), and gel bait S (0.5% dinotefuran). Water loss rate was determined by weighing the gel baits over a period of 20 days. The palatability of gel baits to Blattella germanica was determined by observing the feeding behavior of cockroaches during the same period. The analysis of variance and non-parametric test were used to compare the water loss rate and palatability of the gel baits. Results The three gel baits were dotted indoors for 20 days. Water volatilization mainly occurred in the first day, and the water loss rate was (39.73±0.05)% for gel bait P, (32.49±0.04)% for gel bait W, and (22.99±0.16)% for gel bait S, with a statistical difference between the baits ( F=179.966, P=0.005). The weight of the gel baits was generally unchanged during the following 20 days. Under the fresh condition, the feeding frequency and total feeding time of the three gel baits were in the order of P>W>S. The feeding frequency and total feeding time decreased over time for all the three baits. After 7 days, there were no statistical differences in feeding frequency and total feeding time between gel bait P [(14.33±3.54]times and (518.00±237.91) s, respectively) and gel bait W [(15.67±4.85)] times and (414.00±263.92) s, respectively) ( F=0.246, P=0.631; F=0.428, P=0.528); both gel baits P and W showed statistically higher feeding frequencies and statistically longer total feeding time compared with gel bait S [(4.33±2.21)] times and (38.50±19.75) s, respectively) ( F=14.038, P=0.002, P=0.001; F=7.536, P=0.007, P=0.034). After 14 days, gel bait P had better palatability than gel baits W and S. Conclusion The water loss of the gel baits mainly occurs in the first day after placement. The gel baits have the best palatability in the fresh state, and show different degrees of decreases in palatability with time. In general, gel baits P and W have the best palatability within 7 days. It was not found for the correlation between water loss rate and palatability for the three gel baits.

Objective To study the rodent and cockroach infestations in underground tube wells in Beijing, China, and to provide a scientific basis for prevention and control strategies. Methods A total of 100 streets were selected in Beijing in 2019, and 50 underground tube wells were selected randomly in each street for monitoring (four times). Bait stealing and visual inspection were used for rodent and cockroach density monitoring, respectively. The data were recorded in Excel 2007 software, and a descriptive analysis was conducted. Results Among all the underground tube wells selected in Beijing, the mean value of rodent positivity was 1.06%, and the mean value of cockroach positivity was 0.04%. The number of rodent-positive tube wells was highest (28) in Chaoyang and Haidian districts and lowest (2) in Shunyi district. There were 7 cockroach-positive tube wells, 3 in Fengtai district, 3 in Xicheng district, and 1 in Dongcheng district. Compared with the rural areas, the urban areas had a higher rodent-positive rate of tube wells. Sewage wells had the highest rodent-positive rate (46.92%), followed by electric wells (26.07%) and other wells (12.79%). The main cockroach-infested wells were sewage wells, rainwater wells, and electric wells. Conclusion Varying degrees of rodent infestation were found in the underground tube wells of Beijing in 2019, more severe in the urban areas than in the rural areas. Some administrative divisions had cockroach infestation. Rodent prevention and control in underground tube wells must not be overlooked, and cockroach infestation in underground tube wells should also be closely monitored.

Objective To investigate the effect of residual spraying of lambda-cyhalothrin microcapsule suspension on hedgerow in preventing and controlling mosquitoes. Methods This test was initiated on August 13, 2015, with a duration of one month. Two areas (control area and test area) with similar natural conditions and mosquito density were studied. Residual spraying was implemented using low-volume spray on the leaves (especially the backside) of the hedgerow in the test area. The change in the density of adult mosquitoes after spraying was continuously monitored by the CO ₂ lamp trapping method. The prevention and control effect was evaluated by the decrease rate (%) of relative density. Results After residual spraying of the hedgerow in the test area, the relative density of mosquitoes showed a decrease rate of more than 80% within 2 weeks and a decrease rate of more than 70% at 3 and 4 weeks after treatment as compared with those in the control area (no insecticide treatment). The study above was repeated once in the same place in mid-August, 2017, with the obtained results basically consistent with those in 2015. Conclusion Taking account of environmental safety and sustainable control of mosquitoes, it can achieve a good control effect on relatively high-density adult mosquitoes by standardized residual spraying on hedgerow using proper insecticides and dosage forms under feasible application environments and conditions accompanied by environmental control measures.

Objective To investigate the biting rate dynamics of mosquitoes in Beijing Olympic Forest Park (BOFP), and to analyze the correlation between biting rate and the population density measured by the lamp trapping method. Methods A dynamic monitoring of the biting rate and population density of mosquitoes was conducted by human landing catch and CO ₂ trapping lamp from July to September, 2013. Pearson correlation analysis was performed to analyze the relationship between the mosquito density measured by the lamp trapping method and biting rate, and a linear regression analysis was used to build a linear model for prediction of the biting rate based on the mosquito density measured using the CO ₂ trapping lamp. Results Culex pipiens pallens was the dominant species of mosquito community in Beijing, followed by Cx. tritaeniorhynchus. The biting rate of mosquitoes continuously increased from July to September, and a trough of lamp trapping mosquito density was detected in August. There was a linear correlation between lamp trapping mosquito density and biting rate in July and September, while there was no correlation between them in August. Conclusion The mosquito density measured by the lamp trapping method is closely correlated with the biting rate of mosquitoes. Cx. pipiens pallens is the dominant species of mosquito community in Beijing, and the probability of people being bitten by mosquitoes is significantly correlated with the population density of Cx. pipiens pallens.

Objective This study was intended to elucidate the spatial distribution characteristics of fly density, find correlated environmental factors, and respond to the need of fly control in disaster fields. Methods Respectively, in the study, the spatial statistical analysis was used to detect the spatial aggregation of fly population on the scales of village and town. Furthermore, spatial error regression was performed to uncover the correlated environmental factors with fly density on the same two geographic scales. Results The spatial aggregation of fly population displayed statistical significance in flooding sites on the level of village(Moran's I=0.387, P=0.016)and town(Moran's I=0.381, P=0.039), which means that such spatial pattern was not original from random process. Accordingly, as the spatial regression shown, the fly density correlated with different environmental factor on the scales of village and town; The lighting index values was related to village(Correlation Coefficient=0.514)and town(Correlation Coefficient=1.472)scales, while the slop values related only to the village scales(Correlation Coefficient=-2.398). Conclusion Present paper not only shed light on the fly spatial distribution pattern in flooding area in Fangshan, but also could provide direction for the fly control for any disaster sites being similar to flooding region in Fangshan.

Objective The Centers for Disease Control(CDC), at all levels, are the major institutions undertaking the vector surveillance; the application situation of the four vectors surveillance standards(FVSS)in the Chinese CDC system was analyzed here, and the promotion of FVSS on the business of CDC institutions was investigated at the same time. Methods In the study, questionnaire was used to investigate the awareness and application of FVSS by the CDC institutions, the promotion function of FVSS on the business of CDC institution, and the problem of execution of FVSS by the CDC institutions. Results As the results shown, almost 80 percent of among the CDC institutions, were aware of the FVSS's promulgating and had used the FVSS, and 79.14 percent of them believed that the application of FVSS could standardize their surveillance on vectors. In addition, the FVSS were useful in national hygienic city inspection, hygienic assurance for large-scale events, and emergency response to public health events. However, some problems were also found from the survey:first, 37.41 percent institutions didn't receive any FVSS training courses, the FVSS training should been expanded to cover more institutions; second, many methods in FVSS induced disagreement in vector surveillance and should be modified in the future; third, the FVSS should be consistent with the assessment standard system on the vector control. Conclusion The application situation of FVSS and promotion of FVSS in vector control program by CDC institutions was elucidated, which provided the guideline not only for the using of the FVSS by the CDC institution but also the modification of FVSS in the future.

German cockroach (Blattella germanica), the dominant species of cockroaches in China, has an important role in research due to its significance and harmfulness in medicine and economics and being a preponderant research model for many scientific problems. Functional gene research has been the basis for biological research in the post-genome era. RNA interference (RNAi) is a post-transcriptional gene (mRNA) silencing where endogenous or exogenous double-strand RNA specifically and efficiently suppresses the expression of a functional gene at cellular and gross levels. In view of the research value of cockroaches and the technical advantage of RNAi, this article briefly reviews the molecular mechanism of RNAi, with an emphasis on the latest research on the functional genes of B. germanica.

Objective To determine the residual spray effect of deltamethrin on German cockroach ( Blattella germanica) and the potential relationship between the kdr mutation and the resistance. Methods The resistance ratio of the two field strain B. germanica to deltamethrin was detected by residual contact (glass jar). The forced contact test was conducted to detect the residual spray effect on 3 representative panels of glass, painted wood and cement. The kdr genotype was determined by sequencing. Results The knockdown rate decreased with the increase in the surface water absorption, with the duration of efficacy shortened. The killing effect of the insecticide varied with the resistance status of different strains. The 3 panels were all able to kill the susceptible and low resistance strains effectively, but had no reliable effect on the strain with moderate resistance. Low and moderate resistant field strains that were tolerant to deltamethrin all had the kdr genotype, with the former having a relatively high frequency of heterozygosis genotype (RS), the latter relatively high in the homozygosis genotype (RR). Conclusion B. germanica resistance to deltamethrin residual spray was closely related to the kdr genotypes. Incorrect use of insecticide may result in the increase of kdr genotype frequency, so frequency and dosage need to be adjusted based on the environment types, the target resistance and the insecticide history with residual spray management combined with toxic or gel bait to achieve the ideal control effect.

Objective To analyze the epidemiological characteristics of dengue fever cases from 2006 to 2010 for determination of the risk of dengue fever outbreaks in Beijing. Methods Data of the reported dengue fever cases in Beijing were collected and analyzed for their epidemiological characteristics with SPSS software. CO₂ trapping lamp method was used to monitor the constituent ratio and density of mosquitoes. Results A total of 23 imported dengue fever cases were confirmed, of which 95.65% (22/23) of the cases were at the age of 25-59 years. The male-female ratio was 4.75∶1. Among them, 69.57% (16/ 23) were office clerks. The constituent ratio and density of Aedes albopictus showed 25.71 times and 6.00 times increase in 2010 than in 2007, respectively. Conclusion The density of subdominant mosquito species (Ae. albopictus) has increased in recent years. Vector monitoring and control measures should be implemented effectively to reduce the outbreak risk.

Objective To examine vector prevention and control practices for large-scale events in China by describing vector monitoring and control as a part of pest control operations (PCO) in the 2008 Beijing Olypmic Games. Methods Candidate PCO companies were first screened, and eligible bid winners were then trained and tested, during which the services provided were supervised and inspected by the government designated agency. Results The PCO companies achieved satisfying vector control rates during the 2008 Olympic Games. Conclusion A government-funded pest control model for large-scale events has been established, which utilizes well-trained PCO companies under the management, coordination and supervision of health care administrators knowledgable of technical protocols formulated by the disease prevention and control system.

【Abstract】 Objective To know about West Nile virus （WNV） in mosquitoes during 2008 Beijing Olympic Games, and prevent and control West Nile fever. Methods Mosquitoes were collected by  CO2  lamp  trapping  method.  Two  methods, ADAPCO’s Ramp System and MAS’s VecTest Kits, were used to detect WNV in mosquitoes. Results Compared with 2006 and 2007, the density of main vectors decreased significantly in 2008. Culex pipiens pallens was the dominant specie of mosquito, which constituted ratio reached 96.94% in Beijing Olympic venues. There were 22 275 mosquitoes captured in Beijing Olympic venues that all were negative by detection. Conclusion Mosquitoes were controlled effectively in 2008 Olympic Games. No WNV?positive mosquitoes were detected.

       【Abstract】 Objective To predict the risk indicators of the harm caused by vectors and the occurrence of related diseases during the Olympic Games by risk recognition and assessment methods. To take response measure timely and reduce effectively the harm caused by vectors in order to prevent the occurrence and prevalence of vector?borne diseases. Methods To grade the risk by analyzing the occurrence probability and consequence of risk event comprehensively. Firstly, educe the list and confirm the classification of the risk by literature consultation, empirical analysis, brain storm and expert advice. Secondly, judge the risk level by risk assessment index matrix method and provide the standard to the risk classification. Results The vector?borne diseases and nuisance caused by vectors could be potential during the Olympic Games. For the probability of the public health event caused by vectors, it certainly happens for the biting and infestation of vectors, and probably occurs for environment disruption. It is rare for the occurrence of cables bitten by rodent and power apparatus disruption. The levels of the public health event damaged by vector are as follows: it is moderate harm for the cable bitten and electronic facility disruption, and it is slight harm for the vector biting and infestation or environment disruption. Conclusion The goal that there is no serious harmful events caused by vectors during Beijing Olympic Games would be certainly realized by scientific recognition and assessment of the risk, comprehensive surveillance of vectors, integrated control, scientific using of pesticide, the organization of emergency response team and the generalization of advanced technology.

Objective To develop and implement effective strategies and measures of vector control in order to avoid the harmfulness caused by vectors during the Olympic Games,by analyzing the risks and challenges in vector control.Methods The risk of vector-borne diseases occurrence,nuisance and adverse impact caused by vectors was advanced by analyzing the species,density and the damage of vectors in recent years in Beijing.Control strategies were established according to the monitoring results of the vector population density,resistance and the pathogens in Olympic venues and in urban areas during 2005-2008,as well as the selection of effective control method and management measures.Results The risk of vector-borne diseases occurrence and nuisance caused by vectors existed in Beijing.It was the main control strategies for the vector control in the Olympic Games that included sound management mechanism,a comprehensive density monitoring,the scientific and rational use of pesticide,the consolidated vector control practices,and the organizing of emergency response team.Conclusion It produced the powerful technique support for the vector control of 2008 Olympic Games through the implementation of vectors monitoring and control,the development of vector control technology and the establishment of all kinds of vector control projects.No serious harmful events caused by vectors occurred during Beijing 2008 Olympic Games.

Objective To summarize successful experiences and heritage of vector control by analyzing the vector control efficacy in 2008 Beijing Olympic Games.Methods The density of vector was monitored comprehensively and systematically in the Olympic core area,Olympic venues and outside of Olympic venues.Large-scale vector control activities were carried out in the area within 2 km and the whole city,with Olympic venues as the key places of vector control.Results The density of vector in the Olympic venues and the whole city declined.The public health goal of the Olympic Games,which was "effective control for the quantity and species of vector in the area related to Olympic Games" was realized completely.Conclusion The measures and practices taken in the Olympic Games were effective.The unique experience,technology and control mechanisms were one of Olympic legacy,which would guide vector control practices in Beijing or the whole country in the future.

Objective To select West Nile virus(WNV) quick detecting methods from mosquitoes which can be used in China. Methods Two methods,ADAPCO's RAMP System and MAS's VecTest kits were selected. The sensitivity and accuracy of these two methods and its cross-reaction with Japanese Encephalitis virus were tested. These two methods also were used to detect WNV in wild mosquitoes. Results The results show that both of the two methods can be used to detect WNV. Ramp system is more sensitive than VecTest kits. RT-PCR confirmed that no false positive and false negative results were obtained. These two methods have no cross-reaction in detecting WNV and Japanese Encephalitis virus. 6 species of wild mosquitoes were detected by these two methods. No WNV was found. Conclusion Both of Ramp system and VecTest can be used to detect WNV.

The efficacy test results of Pesguard 5FL are first reported in China. The valid standard is the mortality ≥70 percent, and the valid time with different applied doses on different surfaces could reach 10 weeks. Of the three kinds of surfaces, the three plywood surface required the least applied quantity and gave the best result.

This paper deals with the effects of four pyrethroids and six organophosphates on the fluidity and phase transition temperature of the mitochondrial membrane with fluorescence polarization technique using DPH as a probe. The results showed that the influence of the kind of pyrethroids and organophosphates on membrane fluidity were different. The presence of permethrin or Fenthion、Malathion、Trichlorfon and Omethoate increased the fluidity. But the membrane fluidity were decreased by adding Fenvalerate、Cypermethrin、deltamethrin or phoxim and acephate. Further effect of pyrethroids and organophosphates on the mitochondrial membrane was the shift of the phase transition temperatures. The phase transition temperature decreased by 1℃ in the prescence of Deltamethrin or Acephate、 Omethoate、Fenthion and increased by 2℃、3℃ and 3℃ respectively when adding Cypermethrin or Malathion、 Trichlorfon. Permethrin has no significant effect to phase transition temperature. The results suggest that the effect of pyrethroids and organophosphates on the membrane fluidity may be a critical element in their action mechanisms.