Objective To assess the risk of flies in major industries of Nanchang city, and take measures to control the density of flies at low levels. Methods The invasion of flies in major industries was investigated by method of GB/T 23796-2009. To evaluate the risk of flies in major industries, classification standard of the risk occurrence possibility was established by Delphi method. Results The results of infestation in 2008-2010 showed that flies were likely to do impact people in industries of farm product markets, small restaurants, small foodstores, food processing industry, the station. Flies may possiblly do harm to people in hotels, supermarkets, canteens, tea and dance halls, hospitals. The risk levels have a downward trend in 5-10 month of 2011. To October, there were no risk possibility in industries of hospital (including hospitals), farmers market, enterprises; fixed-point stadiums, hotels, large and medium sized catering site still exists the risk possibility. Conclusion Through environmental, physical and chemical control measures, the density of declined during the period of 7th national intercity games, but some industries still had infestation risks. So it is necessary to take scientific measures to control flies in order to protect the public health.

Objective To establish a rodent risk assessment system for major industries based on risk recognition and evaluation and apply the system to the nine major industries of Nanchang. Methods A indicator matrix was built on the three epidemiological factors with which the risk recognition was initiated to analyze the rodent risk in all industries. Results Different extents of rodent risks were found in the industries, while a high risk of plague, hemorrhagic fever with renal syndrome and other rodent-borne diseases was seen in construction sites, bus stations and farm product markets. Moderate risks were found in hotels, restaurants, hospitals and supermarkets. Conclusion The risk assessment system may be used to predict rodent encroachment on special sectors and provide early warning to inform targeted control strategies.

Objective To determine the association between carboxylesterase (CarE) and beta - cyfluthrin resistance in Musca domestica in various habitats, and monitor this resistance at an early phase by using carboxylesterase. Methods Biological assessment was conducted using dripping titration and the activity of carboxylesterase was determined by the Asperen method. Results Except for the population in transfer stations, the three populations of M. domestica in residential areas, restaurants and farmer's market presented different resistance levels to beta-cyfluthrin with resistance ratios of 1.84, 15.31, 3.19 and 8.84, respectively. The CarE activities in the three populations were significantly elevated (P＜0.05), while 75%, 54% and 72% of them showed remarkably high activities, respectively. Overlapping susceptible strains were found in the three populations except for that in transfer stations. Conclusion Increased CarE activitiy was associated with beta-cyfluthrin resistance in M. domestica. The distribution of high CarE-activity strains showed that the populations in those areas were hybrid resistant strains, which was consistent with the bioassay Results. Based on this finding, it is advisable to restrict the use of beta-cyfluthrin in residential areas and use other pesticides as an alternative to avoid or defer the occurrence of resistance and apply this agent with caution in other habitats.

Objective To determine the population distribution and seasonal fluctuation of rats in Nanchang city. Methods Night trapping and powder trace were employed to survey the rat density in different settings over four years. Results The rodent densities were 1.24% and 5.96% by night-trapping and powder trace, respectively. Two peaks of rat density were found to begin from March and September. Rattus norvegicus, R. tanezumi and Mus musculus accounted for 35.62%, 23.84% and 33.38% in the captured rats. R. norvegicus in residential areas accounted for 56.99%. R. norvegicus and M. musculus in special industries accounted for 49.84% and 27.54%, respectively. M. musculus and R. tanezumi in rural villages accounted for 45.71% and 30.48%, respectively. Conclusion The rodent density in Nanchang was relatively high with obvious seasonal fluctuation. The dominant species had shifted from R. norvegicus to M. musculus, and different dominant species were found in varying environments.

Objective To get insight into the species composition of midges in the Meiling scenic area, providing a scientific base for the control and prevention of blood-sucking midges in the area. Methods The light trap and insect net capture Methods were employed to collect midges in different habitats in the scenic area, and slide specimen were used for the identification of the species in the laboratory. Results A total of 29 species of midges belonging to 5 genera were collected, of which 13 species (11 species belonging to genus Culicoides, 2 species to genus Lasiohel) belonging to two genera, were identified as the blood-sucking midges, with 16 species of 3 genera including 5 species of Dasyhelea, 8 species of Forcipomyia and 3 species of Atrichopogon identified as non-blood-sucking midges. 23 species of midges were found to be new in Nanchang. Conclusion Researches on midges, especially on the blood-sucking midges are not well develpoed and efforts remain to be made to deepen the area in well-rounded manners.

Objective To investigate the rat density in different habitats and the prevalence of major rodent-borne diseases in Nanchang, and to assess the risks of occurrence of rodent-borne diseases. Methods The rodent species was measured using night traps, and data on major rodent-borne diseases were retrieved from the information reporting system for infectious diseases. Risk assessment was completed using the risk assessment matrix. Results From 2006 to 2008, the average density of rats was 1.03% in Nanchang. Rattus norvegicus was the predominant species, accounting for 52.55%, followed by Mus musculus and R. tanezumi, accounting for 18.88% and 17.35%, respectively. The highest rat density, 1.83%, was observed in natural villages of rural areas among the 3 habitats, followed by that in special sectors, 0.89%; and the lowest, 0.56%, was in residential lots. The average incidence of hemorrhagic fever with renal syndrome (HFRS) was 0.68/10⁵ in Nanchang from 2006 to 2008, without human or rodent plague outbreaks in 3 consecutive years. As for the future risk, HFRS occurrence was highly likely in Nanchang, and plague occurrence was possible. Conclusion A scientific risk assessment system may help to predict the risk of disease occurrence.

Objective To determine the resistance of Culex pipiens quinquefasciatus in different habitats in Nanchang to 6 kinds of insecticide such as dichlorvos, providing the basis for development of control measures. Methods The larvae, eggs and adults of Cx. pipiens quinquefasciatus were collected from different habitats in the east, south, west, north and central part of Nanchang city. After 1 to 2 generations of laboratory breeding, the insecticide resistance of the subjects was measured by the impregnation method. Results The resistance coefficients of the mosquitoes from 5 different habitats were 1.19-2.05, 0.57-1.80 and 0.57-1.73 times to propoxur, temephos and dichlorvos, suggesting that the mosquitoes were sensitive to these insecticides. Their resistance coefficients to pyrethroids such as permethrin and cypermethrin were 5.33-56.83 and 10.39-42.17 times, indicating different degrees of resistance. Conclusion There were no insecticide resistance of Cx. pipiens quinquefasciatus against propoxur, temephos and dichlorvos in different habitats in Nanchang, China. On the contrary, there were midium and high resistance against permethrin and cypermethrin. The monitoring of its inseticide resistance should be strengthened in conjunction with proper application of insecticides in order to delay resistance evolution.

Objective The current drug resistance of Musca domestica in different habitats in Nanchang was determined to  provide  the  basis  for  proper  administration  of  pesticides. Methods The  micro?drop  method  was  applied. Results The M. domestica in different habitats in Nanchang had developed varying degrees of tolerance or resistance to dichlorvos, propoxur, deltamethrin, beta?cypermethrin, beta?cyfluthrin and d?phenothrin. The LD50 of the M. domestica strains from the refuse transfer stations were 0.1664, 31.9389, 0.0348, 0.0498, 0.0059 and 0.2551 μg per fly, respectively; the LD50 of the M. domestica strains from the farmer’s markets were 0.1447, 40.7779, 0.0581, 0.0421, 0.0283 and 0.1722 μg per fly; those of the strains in catering industry were 0.1873, 51.7781, 0.0066, 0.0129, 0.0102 and 0.1990 μg per fly; and those of the strains from the residential areas were 0.2828, 39.8730, 0.0416, 0.0798, 0.0490 and 0.2342 μg per fly. Conclusion The M. domestica in different habitats in Nanchang demonstrated intermediate to high resistance to dichlorvos but low tolerance to propoxur, as well as varying resistance to pyrethroid insecticides. Therefore, it is recommended to adopt integrated control measures and scientifically and properly administer pesticides in order to delay or avoid the occurrence and development of drug resistance in houseflies for effective control of M. domestica populations.

【Abstract】 Objective To detect the resistance of Musca domestica in various habitats in early phase with the method of acetylcholinesterase. Methods The  traditional  assay  method  and  acetylcholinesterase  were  used  to  detect  the  resistance  of M. domestica  in  various  habitats  to  dichlorvos (DDVP)  and  propoxur. Results The  bioassay results showed that 4 strains of M. domestica in the residential areas, restaurants, refuse transfer stations and agricultural fair had different resistance to DDVP, and the resistance ratio were 34.07, 22.57，20.05 and 17.43, respectively. The resistance ratio to propoxur was 2.68, 3.48, 2.15 and 2.74, respectively. The DDVP-resistance individual rates of 4 strains in the residential areas, restaurants, refuse transfer stations and agricultural fair were 100%, 82%, 55% and 29%, while propoxur-resistant individual rates of them were 28%, 42%, 12% and 27%, respectively. Except for the strain in refuse transfer stations, the others had resistance to DDVP and propoxur. Conclusion The detection results of acetylcholinesterase were basically consistent with that of bioassays, and it could be used to the early detection of resistance. The 4 resistant strains had middle or high resistance to DDVP and low resistance to propoxur. So, DDVP should be inhibited, and the mixed and rotational use measure could be taken to avoid and delay the development of resistance.

【Abstract】 Objective To illustrate the composition, seasonal fluctuation and the diversity of flies  at different habitants in different months in Nanchang. Methods Cage trapping method was used for the monitoring of fly density, and the species diversity index and evenness index were employed. Results The dominant species of fly were Musca domestica, Chrysomya megacephala and Lucilia sericata in Nanchang. There were two peaks in one year, one in May to June, and the other in  September. The species diversity index and the evenness index were the highest in May, reaching 0.4036 and 0.4229 respectively. In 4 different habitants, both indexes were the maximum in farm market, which were 0.4768 and 0.5280, respectively. Conclusion The population characteristics of flies can be reflected with the species diversity index and the evenness index.

Objective To understand the population structure and the dominant species of cockroaches in Nanchang city nowadays,and to explore the control effect of different control methods.Methods The sticky paper with trapped cockroaches was used to investigate the population structure of cockroaches.The control effect of spray,poison bait and toxic powder on Blattella germanica was tested according to the methods of GB.Results Compared to 2001,the infestation of cockroaches was much heavier nowadays. B.germanica was the absolutely dominant species,which accounted for 99.68% of the total cockroaches.The proportions of B.germanica in the restaurant,hotel,hospital and resident areas were 99.72%,99.81%,95.00% and 92.11% respectively,and there was only B.germanica in the agriculture market.The results suggested that d-cyphenothrin had good effect on B.germanica than lambda-cyhalothrin and alphamethrin.In addition,3 poison baits tested had all good effects,among which sanyecao was the best one,which the LT ₅₀ and the mortality rate at 96 h were 0.08 d and 100%,respectively.Moreover,the mortality rate of two different poison powders were all 100%.Conclusion B.germanica was the dominant species in Nanchang city.The residual spray of d-cyphenothrin,lambda-cyhalothrin and alphamethrin could control it very well,and the poison baits and toxic powders also had good control effect on it.

Objective To control the invasion of Blattella germanica on passenger trains. Methods Several measures were corporately used in this study, including spray, poisonous powder and gel bait. Results Compared to June, the cockroach density decreased 64.79% in July and 90.35% in August. The invasion rate was under 2.0% since August. In addition, in July, the invasion of cockroach decreased 69.76% in the serious invasion carriages, 66.86% in the moderate invasion carriages and 53.85% in the slight invasion carriages, respectively. In August, it decreased 98.79% in the serious invasion carriages, 86.98% in the moderate invasion carriages and 73.63% in the slight invasion carriages, respectively. The serious invasion carriage had never founded in September, and it decreased 95.86% in the moderate invasion carriages and 78.02% in the slight invasion carriages. Conclusion At present, chemical control is still a key measure to control cockroach, and several chemicals combination measure can effectively control the invasion of the cockroach, synchronously strengthening the environment repairs and service quality management.

Objective To understand breeding water bodies and seasonal circle of mosquito larvae for mosquito control.Methods Ladle and container index methods.Results The larvae positive rate of large and middle size of breeding water bodies was 63.16%. Culex,Anopheles and Aedes mosquitoes larvae were found.Larvae were found in 8 of 11 kinds of water bodies.In large water bodies,larvaes growth peak was in June,the density index was 2.88 larvae per ladle.Among 5 different water bodies,the highest density was in kitchen gardens,and its density index was 2.36 larvae per ladle. Culex, Anopheles and Aedes larvae were all found in 4 different kinds of containers.The whole positive rate and density index were 36.06% and 77.03%,respectively,and the peak occurs in June.Conclusion The key time for mosquito control was in June,and the key areas were containers,ground water logging and dirty water.

Objective To evaluate the resistance of Blattella germanica against common used insecticides in Nanchang,and to study the characteristic of carboxylesterase(CarE) in both field and susceptible population.Methods The surface contact method of WHO recommended for cockroach were used for B.germanica insecticides resistance test,and Van Asperen method were used for CarE activity.Results The resistance indexes of dichlorvos,popoxur,deltamethrin,beta cypermethrin were >122.3,1.1,1.4,5.3,4.9 respectively in field population comparing to susceptible strain.The specific activities of the resistant and sensitive strains were 68.7567 mmol/(mgpro·30 min),56.5069 mmol/(mgpro·30 min);The values of K _m were 0.4171 mmoL/L,0.4374 mmol/L;The values of V _max were 0.8525 nmol/(mgpro·min),0.4075 nmol/(mgpro·min) respectively.Conclusion B.germanica in Nanchang developed resistance to most of the tested insecticides but propoxur,and the resistance was associated with the changes of biochemical activities of the CarE.