Objective To investigate mosquito population variation in Jiangsu province, China from 2008 to 2018, and to provide a basis for mosquito control in Jiangsu province. Methods We collected adult mosquito surveillance data obtained using the lamp trapping method at provincial surveillance sites in Jiangsu from 2008 to 2018 to analyze mosquito population variation in urban and rural areas in Jiangsu. The pairwise Kruskal-Wallis test was used for statistical analysis. Results The mosquito density in urban areas, rural areas, and the whole province in Jiangsu from 2008 to 2018 was 7.53, 61.26, and 28.26 mosquitoes/light·night, respectively; in general, the annual mosquito density showed an increasing trend in urban areas, but a decreasing trend in rural areas and the whole province. In the three types of habitats in urban areas, i.e., residential areas, parks, and hospitals, parks were dominant habitats; in the two types of habitats in rural areas, i.e., civilian residences and livestock sheds, livestock sheds were dominant habitats, which were also absolutely dominant habitats among the five types of habitats mentioned above, with a mosquito density over seven times that in other four types of habitats. In the 11 years, the pooled mosquito density by month showed a single-peak variation in urban areas, rural areas, and the whole province, with a peak density in July (17.81, 235.23, and 101.95 mosquitoes/light·night, respectively, for the above three areas); in mosquito seasons, the mosquito density by month in rural areas was 1.50-13.20 times that in urban areas. The composition of mosquito populations in Jiangsu province was mainly Culex pipiens pallens, Cx. tritaeniorhynchus, Aedes albopictus, Anopheles sinensis, An. lesteri, and Armigeres subalbatus; Cx. pipiens pallens was the absolutely dominant species in urban areas; in rural areas and the whole province, the dominant species was Cx. tritaeniorhynchus in most of the 11 years and was Cx. pipiens pallens in the other few years. In most of the 11 years, the density of Cx. pipiens pallens in rural areas was about 2 times that in urban areas, with a significant difference between the two (χ²=15.783, P<0.01); in each of the 11 years, the density of Cx. tritaeniorhynchus in rural areas was over 10 times that in urban areas, with a significant difference between the two (χ²=15.783, P <0.01); the density of the two dominant species showed a single-peak seasonal variation, with a peak density in July. Except for the dominant species, the pooled density by month of other four species was higher in rural areas than in urban areas. Conclusion Remarkable achievements have been made in mosquito control in rural areas in Jiangsu province, while more efforts are needed in urban areas. The focus of mosquito control in rural areas should be livestock sheds and dominant mosquito species; effective surveillance of Ae. albopictus and Ar. subalbatus remains to be pushed forward. The pooled mosquito densities by year and month over the 11 years can provide a preliminary reference for the initiation of mosquito control in Jiangsu province.

Objective The objective of this study was to determine the resistance of Culex pipiens pallens to commonly- used insecticides in Qidong city, Jiangsu to provide scientific evidences for its effective control. Methods Soaking method were used for measuring the insecticides resistance of Cx. pipiens pallens larva to deltamethrin, beta - cypermethrin, permethrin, parathion and fenobucarb. Results The resistance ratios of Cx. pipiens pallens to deltamethrin, beta - cypermethrin, permethrin, parathion and fenobucarb were 1.07, 0.56, 7.36, 6.85, 1.20, in Qidong city, in relation to susceptible population. Conclusion In Qidong city, Cx. pipiens pallens is susceptible to deltamethrin, beta-cypermethrin and fenobucarb, low resistance to permethrin and parathion.

Objective To investigate the susceptibility of Armigeres subalbatus to commonly used pesticides in Suqian city, Jiangsu province. Methods Dipping method was used to detect LC₅₀ of Suqian field population of Ar. subalbatus to abate, fenobucarb, deltamethrin, betacypermethrin and permethrin. Results The LC₅₀(mg/L)of Suqian population of Ar. subalbatus to abate, fenobucarb, deltamethrin, betacypermethrin and permethrin was 0.059 36, 2.563 5, 0.000 457 2, 0.000 443 2 and 0.001 701 respectively, was 7.24, 2.68, 0.21, 0.09, and 0.11 times of LC₅₀ of Suqian population of Cluex pipiens pallens collected from same site on same pesticides. Conclusion Compared with Suqian population of Cx. pipiens pallens, Ar. subalbatus was more resistant to organophosphorus and carbamate pesticides, more susceptible to pyrethroids. IPM was recommended in the control of Ar. subalbatus. Controlling larvae by eliminating of dirty water of vessels and ditches, using pyrethroids or B.t.i. or B. sphaericus biopesticide, were better than controlling adults of Ar. subalbatus, but chemical control on adults of Ar. subalbatus would be the first selection at high vector density or during epidemic period of vector diseases.

Objective To determine the fauna, population density, seasonality, and adverse impact of major vectors in the coastal areas of Jiangsu province, China, and to provide a scientific basis for the prevention of vector-borne diseases in Jiangsu coastal areas. Methods Six coastal counties/cities from Jiangsu province were chosen for surveillance of vectors, and cases of vector-borne diseases in the coastal areas in 2013 were retrospectively analyzed. Results The mean population densities of mosquitoes, flies, rats, and cockroaches in the study areas of Jiangsu province were 1.22 per light-hour, 19.78 per cage, 2.07%, and 0.33 per net, respectively, during June 2002 to 2013. Hemorrhagic fever with renal syndrome (HFRS), scrub typhus, and malaria were the most prevalent diseases in the coastal areas of Jiangsu. The incidence rates of the three diseases in 2013 (1.09/100 000, 1.53/100 000, and 0.76/100 000) were all higher than the average levels in Jiangsu province during the same period. Conclusion The climate and habitat changes in Jiangsu coastal areas may have significant influence on vectors and vector-borne diseases. We need to strengthen publicity and education of HFRS, scrub typhus, and malaria, promote vaccination, and develop pest control in coastal areas. The above measures can effectively reduce the incidence of vector-borne diseases.

Objective To evaluate the effects of integrated cockroach control in supermarket. Methods Three supermarkets, two as experimental sites and one as control, were selected for test. Integrated control measures, which comprised environmental improvement assisted by chemical control, were taken in the experimental sites. The control effects were evaluated with relative density decrease rate as the indicator. Results All the cockroaches captured in the supermarkets were Blattella germanica. Cockroaches were mainly distributed in the fresh food section, cooked food section, storehouse, bakery, food section, vegetable and fruit section, etc., while the cockroach density in the grocery section was relatively low. The cockroach densities in the two experimental sites decreased by 89.96% and 81.38% three days after integrated control measures, by 93.89% and 90.21% three weeks after the measures, and by 95.05% and 89.27% two months after the measures. Conclusion Cockroaches invade the supermarkets seriously, with B. germanica as the dominant species. Integrated control measures can be used to quickly and effectively decrease the cockroach density in supermarket, and the control effects were durable.

Objective To understand the infestation and population distribution of cockroaches in supermarkets in Nanjing city, providing scientific basis for the control of cockroaches in supermarkets. Methods Four large supermarkets located in different positions in Nanjing city were selected and sticky trap method was applied to determine the encroachment rate and the density of cockroaches. The cockroach species were identified with the number counted and the encroachment rate and the density of cockroaches calculated. Results A total of 8894 cockroaches, all of which were Blattella germanica, were captured. It was found that the infestation of cockroaches in the supermarkets was serious with the encroachment rate amounting to 72.64% and the density being 16.78 per piece. Cockroaches were mainly distributed in storehouse, fresh section,deli section, produce section, food section and bakery of the supermarkets, where there were food and water. But relatively light infestation was seen in the department sections. Conclusion B. germanica has become the dominant species in the supermarkets, where infestation of cockroaches is serious, especially in the areas that are rich in food and water. Comprehensive control measures should be taken to effectively reduce the encroachment rate and the density of cockroaches.

Objective To determine the current resistance of Culex tritaeniorhynchus, vector of Japanese encephalitis (JE), to commonly used pesticides in Suzhou city, Jiangsu province. Methods Using the dipping method, the median lethal concentration (LC₅₀) values of deltamethrin, betacypermethrin, permethrin, biothrin, dichlorovos and propoxur were measured for the field population of Cx. tritaeniorhynchus in Suzhou city. Results The LC₅₀ values of deltamethrin, betacypermethrin, permethrin, biothrin, dichlorovos and propoxur for Cx. tritaeniorhynchus were 0.0424, 0.1137, 0.2659, 0.6698, 2.4691 and 7.7017 mg/L, respectively. Intermediately resistant to biothrin, the strain was highly resistant to the other five agents with resistance ratios of more than 50, even 100, to the three pyrethroids. Conclusion In view of the low or higher resistance of Cx. tritaeniorhynchus to multiple pesticides, environmental and biological strategies in conjunction with auxiliary chemical approaches should be deployed for better control of this vector. Administration of pesticides and rational agricultural planning should be carried out based on the big picture. In the event of skyrocketing mosquito density or occurrence of JE epidemic, pesticides should be scientifically distributed and chemical control approaches intensified.

Objective To determine the alteration in the prothrombin time(PT) of Rattus tanezumi from warfarin and its killing effect against the pest in Huaian district. Methods The killing effect of warfarin against R. tanezumi was tested by the food intaking method, with PT done with the special instrument. Results There were 15 R. tanezumi that all died during the observation with an average of 10.13 d for its complete death. The average amount of warfarin consumed (original material) was 2.57 mg/kg, and the average PT (INR) was 1.41, with no statistical significance between the female and male mice found (t=0.159, P=0.876). Conclusion Warfarin could kill R. tanezumi effectively in Huaian district, with the PT value ranging from 0.94 to 2.88.

Objective To determine the current resistance of adult Culex pipiens pallens to commonly used pesticides in Jiangsu province, providing the evidence for better mosquito control. Methods The exposure tube method recommended by WHO was applied to measure the median lethal concentration (LC₅₀) for adult mosquitoes. Results The LC₅₀ for field-collected adult mosquitoes in Nanjing, Xuzhou, Lianyungang, Wuxi, Nantong and Huai’an were 0.0173%, 0.0756%, 0.0487%, 0.0070%, 0.0055% and 0.0150% to deltamethrin respectively, and 0.2128%, 0.2711%, 0.1130%, 0.1579%, 0.0504% and 0.0734% to permethrin, respectively. The LC₅₀ to betacypermethrin for field populations in Nanjing, Xuzhou, Lianyungang, Wuxi, Nantong, Huai’an and Suzhou were 0.0224%, 0.0420%, 0.0843%, 0.0023%, 0.0114%, 0.0180% and 0.0108% respectively. The LC₅₀ for Nanjing population to dichlorovos and propoxur were 0.0119% and 0.0129%, while the values for Nantong population to dichlorovos and propoxur were 0.0046% and 0.0077%, respectively. All of tested mosquitoes were intermediately to highly resistant to deltamethrin, with resistance coefficients greater than 100 times in Xuzhou and Lianyungang; lowly to highly resistant to betacypermethrin, with the resistance coefficient up to 94.7 times in Lianyungang in contrast to 2.6 times in Wuxi; and lowly to intermediately resistant to permethrin, with resistance ratios ranging from 11 to 15 times in Nanjing and Xuzhou, and 2.8 times in Nantong. Nanjing population were lowly resistant to propoxur (2.8 times) and sensitive to dichlorovos, while Nantong strains were susceptible to both propoxur and dichlorovos. Conclusion For adult mosquito control in Jiangsu province, the application of deltamethrin and betacypermethrin should be reduced along with increased administration of carbamates, such as propoxur, and organophosphorus pesticides such as dichlorovos. The findings here address consideration and integrated planning to chemical adult mosquito control for delaying or reducing the occurrence and development of pesticid resistance.

Objective To determine the resistance of Culex pipiens pallens larvae to commonly used insecticides in parts of Jiangsu province, providing the guidance on proper administration of mosquito control agents. Methods Using 7 common chemical pesticides, the resistance of Cx. pipiens pallens larvae in Nanjing, Nantong and Huaian regions of Jiangsu province was measured by larval impregnation. Results Compared with the laboratory susceptible strain, the Cx. pipiens pallens larvae from Nanjing, Nantong and Huaian each had the highest resistance to dichlorvos, while the populations from Nantong and Huaian had the lowest resistance to permethrin. The Nanjing population had the lowest resistance to bioallethrin, and similar resistance to permethrin. Conclusion Suitable insecticides should be used for prevention and control of mosquito larvae, taking into account the regional resistance. To properly apply insecticides, dichlorvos, propoxur, and temephos which mosquitoes are highly resistant to should be gradually replaced by pyrethroids.

Objective To determine the correlation between the occurrence of Culex tritaeniorhynchus and meteorological factors.  Methods Photocatalytic light traps were used to collect mosquitoes in Nanjing suburbs from August in 2006 to December in 2007. Multivariant stepwise regression was conducted using SPSS 16.0 with mosquito density (Y1), female mosquito density (Y2) as the dependent variables and synchronous meteorological factors, including mean temperature (X1), maximum temperature (X2), minimum temperature (X3), precipitation (X4), mean air pressure (X5), mean relative humidity (X6), mean wind velocity (X7) and sunshine hours (X8), as the independent variables.  Results Cx. tritaeniorhynchus accounted for over 90% in Nanjing suburbs, and female mosquitoes 95%. High density (＞60 individuals per hour) was observed in the period from June to October. Significant linear correlation was present between X3 and the changing trend in mosquito densities, despite insignificant regression link. Most meterological factors were significantly nonlinear correlated with the density of Cx. tritaeniorhynchus. Favorable  results  were  obtained  via  the  following  regression  equations: Y1＝10∧［18.645 Lg（X1＋1）－21.403 Lg（X2＋1）－0.930 X7＋0.104 X8＋2.470］－1，Y2＝10∧［19.051 Lg （X1＋1）－21.994 Lg （X2＋1）－0.945 X7＋0.106 X8＋8.675］－1，R2＞0.8.  Conclusion The occurrence of Cx. tritaeniorhynchus could be forecasted based on the concurrent meteorological factors. This prediction method could be applied to other vectors and relevant diseases.

【Abstract】 Objective To   understand   the   relationship   between   the   activities   of   glutathione   S-transferase   and acetylcholinesterase of Blattella germanica and its resistance, and then provide scientific evidence for the establishment of resistance detection by biochemistry. Methods The insecticide film was used to identify the resistance of German cockroach to four kinds of insecticides. The enzyme activity was tested by spectrophotometry. Results The resistance ratio of B. germanica to four insecticides was 1.08, 2.35, 7.47, 10.92, respectively. GSTs activity of resistant strain was much higher than that of susceptibility strain, and the difference was very significant. AChE activity of resistant strain was lower than that of susceptibility strain, and the difference was significant. Conclusion B. germanica had high resistance to beta?cypermethrin and deltamethrin, and low resistance to DDVP and propoxur. The increase of GSTs activity could speed up the metabolism of pesticides, leading to the decrease of B. germanica susceptibility. AChE as an orgnaophosphorus and carbamate insecticides target enzyme,  the decrease of the activity led to the decline of B. germanica susceptibility. The results indicated that the changes of enzyme activity had the close relationship with the development of resistance.

【Abstract】 Cockroaches are the important vectors. The aim of our paper is to understand the biology and ecology of cockroaches, and analyze the present situation of the damage of cockroaches in China. The investigation finds that the invasive species Blattella germanica has become the dominant species and its damage was increasing in urban in China. A brief review is given on the development of the equipments and methods, their advantages and limitations in the control of cockroaches. Cockroaches also play an important role in the infection and allergy. The research and control of cockroaches in China started one century ago and cockroaches control was a long?term and arduous work as facing the challenge of pesticide resistance and pesticide pollution on environment.  It suggests that it should put the emphasis on environment improvement and chemical control to control cockroach, adding law and regulation control, pesticide control, biological control and genetic control, especially the rotational use of control equipment.

Objective To analysis annual dynamics of vectors such as rats,mosquitoes,flies and cockroaches in Jiangsu province from 2002-2007 by studying the regularly monitoring data of vectors in Wuxi city,Nanjing city and Xuzhou city.Methods The night trapping and cockroach paste methods were used for the monitor of rats and cockroaches density.The men-hour and cage-trapping methods were conducted to monitor the density of mosquitoes and flies from April to November,respectively.Results Annual density dynamic of mosquitoes,flies and cockroaches was single-peak curve from 2002 to 2007 and the peak appeared in 2005 or 2006.The density of rats decreased year after year and the constituted ratio of the dominant mosquito Culex pipiens pallens tended to reduce.The constituted ratio of Aedes( Stegomyia) albopictus and Rattus norvegicus( Berkenhout) increased yearly and reached about 10% and 25% respectively in 2007. Blattella germanica(Linnaeus) was the dominant species and its constituted ratio reached 97% in 2007.According to the analysis data monthly of vectors from 2002 to 2007,the density of mosquito had two peaks,and the peak time was in July and September.The flies density had only one peak from June to September,which mainly centralized in September.The peak of cockroach density was from August to September.That of rat fluctuated greatly every month and its peak time was in March and August.Conclusion The risk of vector-borne disease might be worse than before because of the change of vector population and its structure. It should strengthen monitoring and control of vectors and vector-borne diseases in Jiangsu province.

Objective To study annual dynamic of vectors,such as rats,mosquitoes,flies and cockroaches from 2002-2006 in Jiangsu province.Methods Night trapping,sticky card(case) trap were used for the survellence of rat and cockroaches from Jan.to Dec.,indoor-resting mosquito-adults and cage trap method were used for density monitoring of mosquitoes and flies respectively from Apr.to Dec..Topical application was used for pesticide resistance detection of Musca domestica Linnaeus and Blattella germanica(Linnaeus),dipping method or distinguishing dosage method for Culex pipiens pallens Caguillett for dichlorovos,permethrin,cypermethrin and deltamethrin respectively,prothrombin time(PT) were used for the pesticide resistance detection of Rattus norvegicus(Berkenhout) to warfarin.Results Density of mosquitoes,flies and cockroaches increased from 2002 to 2006,the highest of them was 15.20 individuals per hour in 2006, 25.12 individuals per cage in 2005,1.20 individuals per card(case) in 2006 respectively.Density of rats fluctuated,the lowest,0.60% occurred in 2006.Ratio of R.norvegicus(Berkenhout) increased yearly, B.germanica(Linnaeus) turned into one of the dominant species.Exotic species, Ophyra aenescens(Wiedeman) invaded, Cx.tritaeniorhynchus Giles and Anopheles sinensis Wiedemann emerged suddenly and numerously,dominant vector species developed resistance to some normal insecticides.Conclusion For effective vector control,the vector surveillance should be strengthened,to know the dynamic of local vector-population,to emphasize on vector control based on local vector dynamic and vector resistance.

Objective To investigate the resistance of Japanese encephalitis vector mosquitoes( Culex tritaeniorhynchus and Culex pipiens pallens) to four insecticides and know their insecticides resistance in Jiangsu province.Methods Distinguishing dosage method was used.Results ( C.tritaeniorhynchus) developed high resistance to DDVP,while susceptibility to cypermethrin,in Zhenjiang,Nanjing and Huai'an; C.pipiens pallens developed moderate resistance to DDVP,and susceptibility to cypermethrin,in Zhenjiang and Suzhou,while moderate resistance to cypermethrin in Lianyungang.There was a great difference of resistance to some insecticides such as permethrin for two kinds of vector mosquitoes in the same area.Conclusion The vector mosquitoes have developed obvious resistance to some insecticides,which were used for a long time.Cypermethrin could be applied for the control of Japanese encephalitis vector mosquitoes in these areas.

Objective To investigate the community structure and dynamic of potential vector of West Nile Virus (WNV) Disease in Jiangsu Province. Methods Scoop dipping method for larvae,hand collection for indoorresting adults and humanbaited net trap method for outdoor adults were used in Suzhou,Zhenjiang and Lianyungang Cities in Jiangsu Province from April to November in 2004. Results 8 species of 5 genera were collected, Culex pipiens pallens Coquillett, Cx.tritaeniorhynchus Giles and Armigeres subalbatus (Coquillett) were the dominant taxa in suburb, Cx.pipiens pallens Coquillett was the dominant taxon in urban. The highest density of adults occured in September,the high density period was from June to October. The average density was 4.906 individuals per scoop in larvae,22.399 individuals per hour in adults (8.013 in Suzhou City,26.182 in Zhenjiang City,34.944 in Lianyungang City,and 25.757 in suburb,12.632 in urban,28.057 in outdoor). Conclusion The community structure and monthly dynamic of potential WNV vector in Jiangsu Province was preliminary known and further pathogeny evidence was needed.