Objective To investigate the density, infestation rate, seasonal variation, distribution, and population composition of cockroaches in Ezhou of Hubei province, China, and the insecticide resistance of Blattella germanica to eight insecticides, and to provide a scientific basis for the prevention and control of cockroach. Methods In 2016-2020, the sticky trap method was used to monitor the density of cockroaches in six types of habitats, i.e., farmers’ market, supermarket, hotel, catering environment, hospital, and residential area, in Ezhou, and in 2018 and 2020, the residual film method recommended by the World Health Organization was used to determine the insecticide resistance of B. germanica. Excel 2007 software was used for statistical analysis, SPSS 17.0 software was used to perform the Chi-square test of the density, infestation rate, and composition ratio of cockroaches, and median knockdown time (KT ₅₀) was calculated for the results of insecticide resistance. Results The density and infestation rate of cockroaches showed a trend of gradual reduction year by year in Ezhou in 2016-2020, with the highest density of 0.28 cockroaches/trap and the highest infestation rate of 14.37% in 2016, and the lowest density of 0.14 cockroaches/trap and the lowest infestation rate of 6.37% in 2020. Seasonal variation was observed for cockroaches, and a peak was observed in July, with a density of 0.41 cockroaches/trap and an infestation rate of 17.37%. The highest density and infestation rate of cockroaches were observed in catering environment (with a density of 0.46 cockroaches/trap and an infestation rate of 19.51%) and farmers’ market (with a density of 0.31 cockroaches/trap and an infestation rate of 15.57%), followed by hotel and supermarket, and the low density and infestation rate were observed in residential area and hospital. B. germanica was the most numerous species and accounted for 93.55% of total catch, followed by Periplaneta fuliginosa and P. americana, accounting for 5.54% and 0.91%, respectively. The resistance ratios of B. germanica to deltamethrin, beta-cyfluthrin, lambda-cyhalothrin, tetramethrin, permethrin, azamethiphos, alpha-cypermethrin, and acephate were 9.86, 5.08, 3.61, 2.34, 1.76, 1.52, 1.27, and 1.18 between 2018 and 2020, respectively. Conclusion B. germanica is the dominant species of cockroaches in Ezhou of Hubei province, with peak density in July, and catering environment and farmers’ market have the highest infestation rate. B. germanica has moderate resistance to deltamethrin and beta-cyfluthrin and low resistance to lambda-cyfluthrin, tetramethrin, permethrin, azamethiphos, alpha-cypermethrin, and acephate.

Objective To investigate the population composition, density, and seasonal variation of vectors in Hubei province, China, in 2018, and to provide scientific evidence for vector control. Methods The night trap method was used to capture rodents in odd months during January to December; mosquitoes were captured using the light trap method, Breteau index method, and double net method from April to October; flies were caught using the cage trapping method from April to October; the sticky trap method was used to capture cockroaches in odd months during January to December. Results In 2018, the rodent capture rate in Hubei province was 0.36%, and Rattus tanezumi was the dominant species; the density of rats in rural villages and special industries was slightly higher than that in the urban residential areas. The result of mosquito light trap surveillance showed that the mean density of mosquitoes was 12.44 mosquitoes/lamp·night, and Culex pipiens quinquefasciatus was the dominant species; the density of mosquitoes in livestock sheds was significantly higher than that in other habitats. The density of flies was 2.55 flies/cage, and Musca domestica was the dominant species; farmers' markets had the highest fly density (3.95 flies/cage). The mean density of cockroaches was 0.53 cockroaches/trap, and the infestation rate was 7.64%; Blattella germanica was the dominant species; farmers' markets had the highest cockroach density (1.93 cockroaches/trap) and infestation rate (14.44%). Rodents and cockroaches were active throughout the year, and mosquitoes and flies maintained a relatively high density level from May to September. Conclusion The densities of main vectors in Hubei province were at a low level in 2018. The sensitivity of surveillance systems and the level of monitoring, forecasting, and early warning should be continuously improved in the future, so as to provide scientific evidence for the prevention and control of vectors in Hubei province.

Objective To investigate the resistance of Blattella germanica to commonly used insecticides,and to provide guidance in B. germanica control. Methods The B. germanica was collected in Wuhan, Xianning, Huangshi, Jingzhou, Yichang, Jingmen, Xiangyang, Shiyan, Ezhou, and Xiantao cities of Hubei province. Collections were maintained in insectary for further processing. The B. germanica used in this study were the first filial generation(F1). The insecticide film method recommended by the World Health Organization was used to determine the median knockdown time(KT50), the corresponding 95% CI, knock-down rate and the levels of resistance of B. germanica exposed to the five commonly used insecticides. Results The resistance ratios to deltamethrin were high in Wuhan, Yichang, and Huangshi(8.16, 7.71, and 6.48 fold). The resistance also reached the high level to beta-cypermethrin in Jingmen, Wuhan, and Yichang(19.75, 7.06, and 6.75 fold). The resistance ratios to dichlorvos were high in Wuhan, Shiyan, and Jingmen(61.22, 9.13, and 8.35 fold). For propoxur and orthene, the resistance ratios were 6.71 and 4.88 in Xiangyang and Jingzhou city, respectively. Conclusion Field collected strains of B. germanica in Hubei province have already developed different resistance levels to dichlorvos, beta-cypermethrin and deltamethrin. Use of environmental management to eliminate the habitat of cockroaches to minimize the residual spray was proposed.

Objective By monitoring disease vectors to grasp their community structure, density and seasonal fluctuation, and provide scientific data for prevention and control of vector-borne infectious diseases. Methods The disease vector surveillance was carried out in 17 cities and counties in 2015. Rodents and cockroaches were respectively monitored with traps set at night and glue traps; mosquitoes and flies were respectively monitored with mosquito lamps and cage traps. After data collection, SPSS 16.0 and Excel 2003 software were used to carry out the statistical analysis. Results Rodent density of the year was 1.05%, the highest rodent density was in villages. Mosquito density was 1.95 per lamp hour, the highest mosquito density was in livestock sheds. Fly density was 2.13 per cage, the highest fly density was in farmers' markets. Cockroach density was 0.22 per glue trap, the highest cockroach density was in farmers' markets and restaurant. The predominant species were Rattus norvegicus, Culex tritaeniorhynchus, Musca domestica, and Blattella germanica, respectively. The species composition of rodents, mosquitoes, flies, cockroaches all have statistical significance in different habitats. Conclusion The community structure and seasonal fluctuation of vectors in Hubei province were preliminarily known, control measures should be taken depending on the situation.

Objective To investigate the population density of Aedes albopictus larvae and its resistance to commonly used insecticides, so as to provide scientific data for dengue vector mosquito control in Hubei province, China. Methods The density of Ae. albopictus larvae were monitored by Breteau index (BI) method from May to October in 2016, and WHO recommended method-bioassays were performed on the collected Ae. albopictus. With reference to the S-lab (a laboratory strain from National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention), insecticides resistance were tested with dipping method on larvae. Results The population density of Ae. albopictus throughout the year shows a high peak period from May to July, with the maximum index reaches 44.00 in June in Yichang city. The resistance indices were 2.50-15.00 against deltamethrin, 3.56-8.33 against beta-cypermethrin, 3.40-7.45 against permethrin, and 0.31-2.19 against temephos, respectively. Aedes albopictus at all four monitoring sites showed low resistance to beta-cypermethrin and permethrin, and was susceptible to temephos. As to deltamethrin, three sites showed moderate resistance except for the site in Jingzhou city which showed susceptible. Conclusion May to July is a key period for Ae. albopictus control. Integrated management should be adopted and the strategic use of insecticides should be considered to delay the development of resistance.

Objective Survey on ticks and host animals of severe fever with thrombocytopenia syndrome virus (SFTSV) in Huanggang, Hubei province, to provide basic data for the control and prevention of this vector-borne disease. Methods Ticks and animal serum samples were collected from affected areas from April to June in 2013, and SFTSV were detected by Real-time PCR. Results A total of 256 ticks were collected from grassland and livestock, after classification and identification, these collected ticks mostly were classified to 4 species, 4 genus, 1 family, Haemaphysalis longicornis was predominant species. The results of Real-time PCR of ticks, cattle and sheep serum samples showed that infection rates were 3.13%(8/256), 17.65% (3/17), and 12.50% (1/8), respectively. Conclusion Haemaphysalis longicornis was predominant species in Huanggang, the results of Real-time PCR indicated that the SFTS may transmitted by “host animals-to-ticks-to-human”, avoid tick biting is the key to prevent this disease.

Objective The purpose of this paper was to evaluate the efficacy of 0.004% fipronil bait against Reticulitermes in the laboratory and the sites where Reticulitermes occurred. Methods Efficacy test of fipronil bait against Reticulitermes chinensis was conducted in the laboratory and efficacy test against R. chinensis and R. flaviceps of was conducted in the buildings where Reticulitermes occurred. Results In the laboratory, the death of R. flaviceps occurred massively after feeding with bait in three days. The average mortality rate reached to 78.00%. All of the workers and soldiers were dead in 8 d. The average feeding rate of baits was 5.15%. For the application studies, fipronil bait was used in 15 office buildings and residences for R. chinensis and R. flaviceps from 2009 to 2015. Reticulitermes were wiped out by a single application for 13 sites, and twice, three times for the other 2 sites, respectively. Conclusion Reticulitermes chinensis and R. flaviceps could be effectively controlled by 0.004% fipronil bait in the sites where they occur.

Objective In this study, we investigated the population densities and resistance to commonly used insecticides of Culex pipiens quinquefasciatus in Wuhan, Hubei province. Our results can provide new insights into field mosquito control operations. Methods According to GB/T 23797-2009, lamp traps were used to caputre mosquitoes during March to November in 2014. The larve impregnation method which is recommended by WHO, was used to determine the susceptibility of larve (LC₅₀ with 95%CI) to deltamethrin, DDVP, DDT, propoxur and temephos. Results The population densities of C_x. pipiens quinquefasciatus throughout the year showed a single peak between May and June, the average density in stables was significantly higher than any other habitats. The LC₅₀ values of deltamethrin, DDVP, DDT, propoxur and temephos of C_x. pipiens quinquefasciatus were 0.071 7, 0.469 9, 0.766 0, 0.941 0 and 0.000 78 mg/L, and the resistance ratio were 358.50, 151.14, 42.56,9.72 and 1.30, respectively. Conclusion Our data showed that the peak population densities of adult C_x. pipiens quinquefasciatus was between May and June in Wuhan, it is also the key month for mosquito control. Considering the prevalence of resistance to chemical insecticides among mosquitoes, integrated management should be promoted to delay the development of resistance.

Objective To investigate the species composition of murine-like animals in the Macheng city, Yingshan county, Suizhou city, Xian'an district, Chongyang county, and Xingshan county of Hubei province, China, where there has been high incidence of severe fever with thrombocytopenia syndrome (SFTS), and to provide a scientific basis for the control of this disease. Methods The night trapping method was used to capture murine-like animals. Results Niviventer confucianus was the dominant species outdoors in Guangshui county and Sui county of Suizhou city, accounting for 58.88% of all captured rodents in this area. N. confucianus was the dominant species in Xian'an district, accounting for 68.18% of all captured rodents in this area. Crocidura attenuata was the dominant species in Macheng city and Xingshan county, accounting for 40.48% and 66.67%, respectively, of all captured rodents in local areas. Rattus tanezumi was the dominant species in Yingshan county and Chongyang county, accounting for 43.75% and 47.06%, respectively, of all captured rodents in local areas. Most of captured rodents were female. Conclusion The species composition of outdoor rodents varies greatly between the epidemic areas of SFTS in Hubei province, with N. confucianus, R. tanezumi, and C. attenuata as the dominant species, and most of the captured rodents are female.

Objective To observe the control effects of 10% boric acid gel bait on cockroaches in the laboratory and field and compare it with residual spray in killing cockroaches. Methods The killing effects of 10% boric acid gel bait and residual spray were observed in the laboratory and simulated field according to the national standards GB/T 17917.7-2009 and GB/T 17917.10-2009. The decrease in cockroach density was determined by visual measurement after residual spray and application of gel bait in the field, and the killing effect was evaluated accordingly. Results In the laboratory and simulated field, all Blattella germanica died 2 d after treatment. In the field, the average density of B. germanica was 169.25/15 min before residual spray; the density decreased by 9.60% and 6.29% in the first and second weeks after residual spray of 10% cis-cypermethrin suspoemulsion plus 80% DDVP; then, residual spray of 10% cis-cypermethrin emulsion plus 20% propoxur EC was performed, and the density decreased by 6.63% and 5.51% in the third and fourth weeks. Finally, 10% boric acid gel was used, and the average density of B. germanica decreased by 94.10% and 100% in the first and second weeks after treatment. The average density of B. germanica was 1.38/15 min 1 month later. Conclusion The B. germanica population with high insecticide resistance is difficult to be control by residual spray, but 10% boric acid gel bait has good control effect on cockroaches and causes little insecticide resistance. Gel bait is recommendable for cockroach control.

【Abstract】 Objective To learn the resistance situation of Musca domestica from different areas in Hubei province to common insecticides and study its control measures.  Methods Topical application was used in this study.  Results The surveillance results indicated the average LD50 values of DDVP to housefly from different areas was 0.2256, 0.1908 and 0.4428 μg/housefly from 2005 to 2007, respectively. The average LD50 of alpha?cypermethrin was 0.0841 and 0.1102 μg/housefly in 2006 and 2007, respectively. The average LD50 of deltamethrin was 0.0371 and 0.0825 μg/housefly in 2005 and 2007, respectively. The average LD50 of etramethrin in 2005 and 2006 was 0.3952 and 0.2894 μg/housefly, respectively. The average LD50 of acetophenate in 2005 and 2007 was 0.3264 and 0. 3487 μg/housefly. Conclusion M.domestica had high resistance to organic phosphorus and pyrethrum insecticide in Hubei province. No obvious resistance against acetophenate had been found. The mixed and rotation use of insecticides contributed to the control the resistance development of M.domestica.

Objective To study the resistant development of Rattus norvegicus to anticoagulant rodenticide after its application in Qichun county.Methods The resistance of R.norvegicus was tested according to the method established by Rodenticide-resistance Monitoring Cooperation Group of China.Results The resistance of R.norvegicus was detected in 1990,1995,2000,2002,2005 and 2007,respectively.There were 208 rodents tested,and only one rodent survived in each of three times resistance monitoring.Whether the test rodent were male or female,the minimum and maximum average lethal dosages in 2000-2008 resistance monitoring was all lower than that in 1995.But the average lethal time postponed a little compared to that in 1990.Conclusion After the application of anticoagulant rodenticide for 23 years in Qichun, R.norvegicus was still highly susceptible to the first-generation anticoagulant rodenticides,and its tolerance capability was lower than that of R.tanezumi and Mus musculus.Therefore,the anticoagulant rodenticides could be still used to kill R.norvegicus.