ISSN 1003-8280 CN 10-1522/R 中国疾病预防控制中心 主办
Objective To optimize the method for the extraction of mosquito mitochondrial genome DNA. Methods The optimized method was improved from the protocol for the extraction of animal mitochondrial genomes, and was based on the modification for high-concentration-salt precipitation and nuclear DNA removing. The mtDNA samples were tested using spectrophotometry, agarose gel electrophoresis and amplification products of COⅠ. Results The method was showed to be rapid and efficient for single mosquito in our studies. The gel electrophoresis demonstrated that the mtDNA samples extracted were essentially free of nuclear DNA and protein. A number of applications with different mosquito species indicated that the method was highly suitable to extract the mitochondrial genome DNA of individual mosquitoes. Conclusion The optimized method is easy and efficient for mosquito samples, and the extracted mtDNA is high quality and suitable to studies on mitochondrial DNA.
Objective To study the characteristics of mitochondrial DNA cytochrome oxidase subunitⅠ (mtDNA-COⅠ) gene and the spatial population genetic diversity of Aedes albopictus in Shenzhen. Methods Larvae of Ae. albopictus were collected from eight investigation sites in Longgang, Guangming, Futian,Dapeng, Luohu, Longhua, Nanshan and Baoan district, and reared in the laboratory, and the resulted adults were preserved in 75% alcohol under -20 ℃. Single mosquito genomic DNA was extracted from Ae. albopictus of different populations, and mtDNA-COⅠ gene were specifically amplified by PCR. The amplified mtDNA-COⅠ gene sequences in different geographic strains were analyzed and compared with the others in the GenBank, and genetic polymorphism analysis of them was conducted by bio-information system. Results The obtained COⅠ sequences of Ae. albopictus of eight different isolates from Shenzhen showed 99% homogeny with 1433 bp in length. As there were transition and transversion in the mononucleotide of mtDNA-COⅠ gene, Ae. albopictus from different geographical locations in Shenzhen showed gene polymorphism in sequence analysis on mtDNA-COⅠ with 24 mutation sites and 1.67% mutation rate. However, there was no difference in gene sequence of mtDNA-COⅠ in the five mosquitoes of Ae. albopictus from the same geographical location. Conclusion The mtDNA-COⅠ gene of Ae. albopictus from different collection sites of Shenzhen have high homogeny, but single nuclear polymorphism(SNP) was also observed among different Ae. albopictus populations. The SNP forming reason needs to be further studied.
Objective In order to know the species, insecticide susceptibility, application, raising conditions and keeping staff of laboratory disease vectors, we carried out the survey in 2013. It helps to establish the Chinese standard system of laboratory vectors and promote the study of the discipline. Methods The respondents included all levels of the Center for Disease Control and Prevention, scientific institutions and some of the Universities in China. The survey was carried out with telephone and email questionnaire. Data were analyzed with the statistical methods to know the results all about the laboratory vectors. Results We received 49 questionnaires from 45 agencies. There were 214 kinds of vector populations of laboratory vectors including mosquitoes, flies, cockroaches, fleas, ticks, bed-bug, rodents and other pests of public health. Among them, 71.03% of laboratory vector populations were susceptible to certain pesticides. The purposes to breed and maintain the laboratory vector populations were the evaluation of insecticide products for public health, research on vector control technology, surveillance of insecticide resistance, study on the vector ecology and the mechanism of vector-borne diseases transmission. Conclusion The populations of laboratory vectors were abundant in China and the majority was mosquitoes, cockroaches and flies. However, some important disease vectors, such as sand fly, were absent from the Chinese laboratories according to this survey.
Objective To better understand the molecular epidemiological characteristics of emerging spotted fever group Rickettsiae and Anaplasma phagocytophilum identified in Hebei province. Methods One hundred and one clinical probable cases of typhus were collected from Xinji city, Qianan city and Dingzhou city, Hebei province during 2009-2012 and 101 acute stage and 17 convalescence blood samples were collected. Sera separated from blood were used for detecting the IgM and IgG antibodies against Rickettsiae prowazekii, R. typhi, R. felis, Bartonella henselae, Orientia tsutsugamushi, R. heilongjiangensis, R. sibirica, Ehrlichia chaffeensis, Coxiella burnetii, Chinese spotted fever group rickettsia Hainan-1 and Chinese A. phagocytophilum strain CZ-HGA-2 and LZ-HGA-3, respectively. Two sets of nested PCR, which targeting the A. phagocytophilum 16S rRNA gene and spotted fever group rickettsiae groEL gene respectively, were conducted using the acute stage blood DNAs of patients as temples. Sequences were analyzed by DNAStar MegAlign. Results PCR positive rates were 10.9%(11/101)for amplifying groEL gene and two genetic groups of spotted fever group rickettsiae were identified. Although the sequence analysis failed to differentia the emerging spotted fever group rickettsiae from traditional ones because of limited PCR fragments, the sera from the patients with positive PCR did not reactive with the R. heilongjiangensis, R. sibirica, R. felis, and Chinese spotted fever group ricketsia Hainan-1, which indicated that the emerging spotted fever group rickettsiae might be prevalence in these areas. PCR positive rates of A. phagocytophilum were 8.9% (9/101) and all of the 9 patients with positive PCR were found to be positive of the IgM antibodies against A. phagocytophilum and 3 patients had IgG seroconversation (4-fold increase of IgG antibody titer). The 9 sequences of the 16S rRNA genes of A. phagocytophilum were not only 100% identity with each other but 100% identity with the local A. phagocytophilum strain CZ-HGA-2. Conclusion Emerging tick-borne rickettsiae were highly prevalence in Hebei province and further etiological investigations were urgently needed.
Objective To describe the procedure of building Elman neural network model, and explore the value of potential application of the above model. Methods Monthly incidence of hemorrhagic fever with renal syndrome(HFRS) in China from 2004 to 2013 was used to build Elman neural network model and SARIMA model and forecasted the monthly incidence of HFRS in China from January 2014 to September 2014. The fitting and prediction effects of the two models were compared. Results For training sample, MAE, MAPE and RMSE of Elman neural network were 0.0088, 0.1191 and 0.0127 respectively; MAE, MAPE and RMSE of SARIMA model were 0.0111, 0.1268 and 0.0206 respectively. For predicting sample, MAE, RMSE and MAPE of Elman neural network were 0.0079, 0.1180 and 0.0096 respectively; MAE, RMSE and MAPE of SARIMA model were 0.0178, 0.2778 and 0.1861 respectively. Conclusion Elman neural network fits and forecasts the HFRS incidence trend in China well, and the fitting and prediction effect is superior to the SARIMA model, which is of great application value for the prevention and control of hemorrhagic fever with renal syndrome.
Objective To investigate the distribution, species, and seasonality of ticks and rodents and detection of severe fever with thrombocytopenia syndrome virus (SFTSV) in vectors and hosts. Methods In seven counties of Zhejiang province, the free ranging ticks were collected by flagging and the parasitic ticks were collected from the host skin by hand searching on a 3-month basis of 2013. Rodents were captured by squirrelcage method. The specimens of liver and spleen were collected with sterile operations. The SFTSV nucleic acid in the viscera of rodents and in the ticks were detected by fluorescence quantitative RT-PCR. Results A total of 751 ticks were collected, consisting of 2 families, 5 geniuses and 6 species, including 439(58.5%) Haemaphysalis longicornis, which were the predominant species in Zhejiang province. The ticks species distribution varied in different counties in Zhejiang province (χ2=1198.409, P < 0.05). Ticks were active from March to October and the peak was in the second 3-month of the year. The total number of captured rodents was 1078, the rodentia belonged to 13 species in 7 genera in 3 families. The insectivora belonged to 2 species in 2 genera of 2 families. The predominant captures were 355(32.9% ) of Apodemus agrarius and 326(30.2% ) of Eothenomys melanogaster. The distribution of the rodent species also varied in different counties in Zhejiang province (χ2=1623.480, P < 0.05). The results were negative in RNA detection of SFTSV in the specimens of ticks and rodents by RT-PCR. Conclusion The vectors and the host animals of SFTSV were found in Zhejiang province. But the vectors and the possible hosts need further studies.
Objective To get epidemiological data on plague hosts and vectors in the history of plague epidemic in Zhejiang province, and providing scientific basis for the prevention and control in the province. Methods The rodents were captured in the 20 surveillance sites in the province by trapping, then calculated the rodent density, flea index, flea infected rates, SPSS 17.0 software was applied for statistical analysis of the data; The animal livers and spleens were collected for Yersinia pestis culture and used for indirect hemagglutination assay (IHA) detection F1 antibody of Y. pestis. Results The average indoor and outdoor rodent was 4.19% and 4.47%, there is a considerable difference between the rat density in different regions. The capture was 50 680 rodents, belong to 3 orders, 5 families, 9 genera and 16 species (Subfamily). There were 32 482 rodents and 1062 that were processed. Average flea infected rate was 3.27%, the flea infected rate were different among species, with statistical significance (χ2=3723.567, P=0.000). The fleas are 7 species from 3 genera and 3 families, among different areas there were significant differences (F=5.659, P=0.000). No plague were cultured or detected in 46 881 rodent samples and 49 327 serum samples. Conclusion The composition of plague hosts and vectors is stable, no mouse and human plague epidemic, however plague surveillance standardize should strengthen to be prepared for emergency and plague resurgence.
Objective The Metro system is an important part of urban transportation, rodents can cause damages which lead to transit malfunctions. Rodent invasions were investigated in the Shanghai metro system. Methods Visual observations of standardized areas (15 m2) and food lure method were used in the investigation. Results Both showed evidence of rodent activity (3.8% for visual observation method and 9.8% for food lure method respectively). Conclusion Rodent invasions have been found in the Shanghai metro system. Rodent infestation will rise up along with the service time of the metro lines.
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 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 Multicollinearity among common temperature parameters was analyzed to get suggestions for establishing the temperature driving model of insect population. Methods SPSS 13.0 was used to analyze pairwise correlation of daily average temperature (X1),maximum temperature (X2), lowest temperature (X3), 18:00 temperature (X4) and five days' average temperature (X5), which was collected from 2010 March to 2011 November. Meanwhile multicollinearity of temperature parameters was diagnosed based on mosquito population model droved by temperature. Results There was an extremely significant (P < 0.01) linear correlation between the various parameters. The coefficient of determination between X1 and X2 is the highest (Rc2=0.959); and it was the lowest between X4 and X5 (Rc2=0.811). Conclusion There were extremely significant correlation between any two temperature parameters discussed in this paper. These five temperature parameters had strong multicollinearity in mosquito temperature driving model. Multicollinearity weakened the model regression goodness. Simultaneous application of multiple temperature parameters should be avoided when introducing the temperature factor to establish temperature driving model.
Objective To investigate and analyze distribution of Anopheles sinensis density from 2012 to 2014 in peripheral areas of Beijing Capital International Airport (BCIA), and evaluate the existence of the transmitting mosquitoes of malaria in an effort to provide theoretic basis for the construction of Risk Assessment and Early Warning System. Methods According to GB/T 23797-2009, capture method of light-traps was adopted in mosquito surveillance. Epidemiological analysis was carried out on mosquito density monitoring from 2012 to 2014. Analysis of variance was adopted in statistical analysis. For the capture of An. sinensis for four kinds of Anopheles to Plasmodium nucleic acid detection. Results Mosquito density index was 34.66 mosquitoes per light-trap in 1 hour. In total 103 231 adult mosquitoes were captured within 3 years, Culex pipiens pallens was the predominant species, accounting for 85.05%, and the An. sinensis (0.09%). The annual average densities of An. sinensis were 0.04, 0.03 and 0.03 mosquitoes per light-trap in 1 hour, respectively. Mosquito densities were not significantly different among 2012, 2013 and 2014 (F=0.310, P > 0.05). The adult An. sinensis were captured from May to September. The densities of An. sinensis in seven surveillance sites monitoring points were 0-0.17, there were significant differences among seven monitoring sites(F=10.548, P < 0.01). The test results of mosquito-borne malaria parasite carrying status were negative. Conclusion The transmitting mosquitoes of malaria exist at BCIA, Beijing has faced potential risks of malaria prevalence by imported cases (Overseas and other provinces infections). It is necessary to continuously strengthen monitor for An. sinensis at BCIA.
Objective To get an insight into the species composition, distribution and virus-carrying condition of host animals in Xi'an of hemorrhagic fever with renal syndrome (HFRS) in 2012. Methods Night trapping method was used to capture murine-like animals, and their habitats were recorded, and extracted RNA and genotyping of Hantavirus(HV) carried by the animals, the differences in rodent density, and virus-carrying rate between different months were analyzed by using t -Test, and the differences of rodent density in different habitats were analyzed by using general linear models. Results There were 480 murine-like animals were captured belonging to 12 species/subspecies of 6 genus, 4 families, and 2 orders in 2012, the density of animals in the field (9.42%) was higher than in the populated area (3.93%) (F=4.555, P < 0.05). There were significant difference in rodent density and virus-carrying rate among different months(t=4.900, P < 0.05; t=5.894, P < 0.05). Animal density began to significantly increase from May, and reached its peak in August, and then drop after November. The virus-carrying rates of animal were 28.53% in the field and 0 in the populated area. Three species were virus - carrying animal, which were Apodemus agrarius, Mus musculus and Crocidura suaveolens. All the genotypes of 119 positive rodents belonged to typeⅠ (hantaan virus, HTNV). Among these positive rodents, A. agrarius accounted for 97.48%, and its virus-carrying rate was 31.52%. Conclusion Apodemus agrarius is still the main host species of virus which causes HFRS in Xi'an. Controlling density of field murine-like animals should be the key to prevent HFRS, and taking comprehensive measures for controlling animal density should begin in April.
Objective To learn the vector infestation status in five-star Hotels of Huangpu district before the CICA- Summit, and to provide scientific justification for vector prevention and control. Methods Randomly selecting 10 five-star hotels responsible for CICA-summit reception,the vector infestation status in these hotels were investigated in visual method and evaluated according to the Shanghai Local Standards. Results The failure rate of rodent control in 10 hotels was 40% and 10% (4 and 1) respectively in the two rounds of survey. There was significant improvement after the first round feedback, the positive rate decreased significantly (1.24% vs. 0.38%, P=0.048) and the pass rate of rodents was improved significantly (97.19% vs. 99.10%, P=0.006). The cockroach control failure rate was 40.00% and 50.00%, respectively, the positive rate also decreased significantly after the first round feedback (1.87% vs. 0.74%, χ2=3.942, P= 0.047). The positive mosquito breeding sites was found in individual underground garage wells. No obvious fly and bedbug infestations were found in the two rounds of survey. Conclusion Five-star hotels vector infestation were found mainly in the kitchen, food storage and processing rooms, laundry rooms and other non-public areas, mice and cockroaches were the predominant vector for infestation, which may be attributed to the hotels'complex environment and management deficiencies. Appropriate pest proof measures, specific supervision, modifications and improvement in the star hotel standards were advisable.
Objective To determine the efficacy and dosage of the different fipronil formulations against fly and cockroach. Methods GB/T 13917.1-2009 Laboratory efficacy test methods and criterions of public health insecticide for pesticide registration - Part 1: Spray fluid; GB/T 13917.7-2009 Laboratory efficacy test methods and criterions of public health insecticide for pesticide registration-Part 7: Bait and GB/T 13917.10-2009 Laboratory efficacy test methods and criterions of public health insecticide for pesticide registration-Part 10: Analogous site are adopted to test and evaluate the efficacy of the fipronil formulations. One-way ANOVA and Independent-Samples t test are adopted for the comparison of the efficacy of the different groups. Results Three kinds of 2.5% fipronil flowable concentrates from different factories belong to rank A according to the national standard. Among the six different fipronil micro-emulsions, five of them belong to the rank A and B. There is no significant difference between 3% and 6% fipronil micro-emulsions on the efficacy against fly (P > 0.05). The 0.05% cockroach bait belong to the rank A, which has no significant difference with other baits (P > 0.05). Conclusion Different fipronil formulations have high efficacy against fly and cockroach, but should be used in lower dose.
Objective To understand the resistance of Blattella germanica in five areas of Shaanxi province and provide instruction to the use of insecticides. Methods Residual film method. Results The resistance index of field-collected strains of B. germanica were 1.08-3.69 to acephate, 1.04-4.10 to DDV, 1.30-9.69 to cypermethrin, 1.77-5.40 to beta- cypermethrin, 1.67-4.05 to deltamethrin, 1.28-9.74 to propoxur. Conclusion Insecticides should be applied scientifically to manage the increase in insecticidal resistance of B. germanica effectively.
Objective To identify the species compositions, densities and seasonal fluctuation of vectors in Zhejiang province from 2011 to 2013, the aim is to provide scientific and technical support for the prevention and control of vectors. Methods Mosquitoes, flies, rodents and cockroaches were monitored with mosquito lamps, cage traps, traps set at night and glue traps. Results From 2011 to 2013, the mosquito density was 1.52, 1.33 and 1.62 per lamp-hour, respectively, with the highest density found in livestock pens, and the dominant species were Culex pipiens pallen (sure not Cx. quinquefasciatus), accounting for 57.44%. Mosquitoes appeared from April and peak in June through August. The fly density was 8.77, 5.67 and 3.47 per cage, respectively, with the dominant species were Chrysomya megacephala from 2011 to 2012, which became Musca domestica in 2013. The rodent density was 0.89%, 0.81% and 0.78%, respectively, with the dominant species were Rattus norvegicus, accounting for 57.70%. Rodents were observed throughout the whole year. The cockroach density was 0.54, 0.37 and 0.35 per glue trap, respectively, with the dominant species were Blattella germanica, accounting for 88.42% . Conclusion Species compositions, densities and seasonal fluctuation of vectors in Zhejiang province were analyzed through 3-year surveillance, mitigation measures should be taken accordingly to control vectors.
Objective To understand the Calliphorid flies'distribution for providing a scientific basis to prevention of infectious diseases by flies. Methods All flies specimens were collected with mist net from the fields, then identified under a microscope, examined against historical literature. Results A total of 118 species of Calliphoridae were identified to belong to 5 Subfamilies, 11 tribes, and 33 genera. The 118 known species accounted 45.04% for total of 262 species in China, among which 63 new species and 54 indigenous species which accounted 53.39% and 45.76% for known species from Sichuan province respectively. Conclusion Sichuan province has a vast territory, the topography and landforms complex, rich in biological resources, Calliphorid species represent the local biodiversity, which warrants further studies in the future.
The paper reports and describes two new species Phaonia pingbaensis sp. nov. and Phaonia subpilosipennis sp. nov., which are collected from Guizhou, China and assigned to the Phaonia latipalpis-group. The type specimens of two new species were collected from Guizhou, China and are deposited in WEI Lian-meng Labor Model Innovation Studio of Center for Disease Prevention and Control of Anshun city, Guizhou 561000, China.
Objective To investigate the distribution of Aedes aegypti in border area in Yunnan province, providing scientific information for dengue control. Methods The distribution of Ae. aegypti was investigated by collecting mosquito larvae in different breeding sites and identifying fourth instar larvae; Aedes mosquito larva population density was investigated by Aedes Breteau index and container index. Results Total of 159 924 containers were investigated from 17 border counties, of those 2388 containers were positive; the Breteau index was 3.97, the container index was 1.46. There were 7489 individual larvae were collected, belonging to 3 species, of those 3303 individual larvae were Ae. aegypti, accounting for 44.10% of total collected larvae, 4119 individual larvae were Ae. albopictus, accounting for 55.00% of total collected larvae,12 individual larvae were Ae. annandalei, accounting for 0.90% of total collected larvae. Aedes mosquito larva population density peaks were occurred from May to October, its highest peaks were July and August. Ae. aegypti distributed in 7 counties i.e. Jinghong, Mengla, Menghai, Yingjiang, Longchuan, Ruili and Lushui. Conclusion Aedes aegypti distributed in 7 border counties of Yunnan province, and results suggested that its distribution was expanding to the neighbor areas, which warrants high attentions by disease control department.
Objective To understand the strain of serotype, biotype, virulence genes, which cause infantile diarrhea. Methods Bacterial culture, serum agglutination method and PCR were used for serotyping, detection of virulence genes. Results A strain of Yersinia enterocolitica was isolated from the children of feces sample and the short bacillus of gram stain negative was identified under the microscope. Oxidase of the bacteria was negative, katalase was positive, no hydrogen sulfide production, urease test positive, ONPG test positive. The Y. enterocolitica strain is positive in O:3 serotyping test and it belongs to 3 biological types, carrying the virulence genes of ail+, ystA+, yadA+, virF+ but no ystB- . Conclusion The case of infantile diarrhea disease is caused by pathogenic Y. enterocolitica.
Objective Through investigation on plague F1 antibody of domestic dogs, determining whether there is the clue of plague epidemic, and providing guidance of plague prevention and control. Methods Three methods were applied for detection of plague F1 antibody on the acquisition of canine sera, they are indirect hemagglutination test (IHA), enzyme linked immunosorbent assay (ELISA), and colloidal gold immunochromatographic test (GICA). Results In Deqin county, 1051 dogs sera were tested. 3 serum samples were IHA positive, 32 were ELISA positive, 14 were GICA positive, the positive rate were 0.29%, 3.04%, 1.33%. None of 73 was positive in Shangri-La county. Conclusion According the clue obtained, it is necessary to conduct further investigation to confirm the existence of plague natural foci, then formulate monitoring scheme.
Objective To know whether the imported Oncomelania snails could survive in a simulated environment. Methods Snails from Guichi, Anhui province were put into the ponds of 4 square meters on each with densities of 25, 50, 100, 200, 400 and 800 pairs. In the next 2 years, the activities of the snails and their offspring snails were recorded by some person every day. Statistical methods were used for this experiment. Results The Total No. snails declined on soil surface among the two years. Wilcoxon W Test and Kruskal - Wallis test were used to analyze total No. snails and No. filial generation snails on different densities respectively, results showed that there were statistical significances on total No. snails and No. filial generation snails except 12.5 snails per square and 100 snails per square groups. The statistical formula on total No. snails to different densities in 2011 and 2012 were Y=19.08Inx－21.66 (R2=0.217, P < 0.01) and Y= 6.31Inx－6.09 (R2=0.299, P < 0.01). On 2011 and 2012, the statistical formula on No. filial generation snails to different densities were Y=0.05Inx+0.14 (R2=0.002, P > 0.05) and Y=0.39Inx－0.13 (R2=0.041, P < 0.01). Conclusion The oncomelania snails can survive in the soils in neighborhood province. But there wasn't any snail establishment in the two years.
Objective Establishment of Aedes caspius laboratory breeding methods, to evaluate the resistance in Ae. caspius to commonly used insecticides in Kalamay. Methods Conventional breeding Ae. caspius and determined via the dosing method and median lethal dose method to detection F1 generation. Results Under conditions of temperature of (26±1) ℃ and the relative humidity of (40-60) %, the time of egg was 3 d, the time of larva was 7 d, the time of egg to emergence was 11 d, an egg batch resulted in about 110-120 larvae (does Ae. capius lay eggs singly). The LC50 values of DDVP, propoxur, deltamethrin, β-cypermethrin, and biothion to larvae of Ae. caspius were 0.2838,2.7752,0.0024,0.0126, and 0.0033 mg/L respectively. Conclusion The LC50 values for commonly used insecticides to Ae. caspius is similar to Ae. albopictus. Breeding place should be administered first in controlling Ae. caspius and insecticides should be used properly to avoid resistance development.
Objective To determine the species and density of cockroaches and their seasonality in the urban areas so as to provide evidence for scientific control of cockroaches in Changzhou. Methods The density of cockroaches was monitored by sticky-trap method and were then identified and counted. Results There were 3 species of cockroaches distributing and testing for 3 species under 2 genera, 2 families, and Blattella germanica was the predominant species, accounting for 92.16%. The active peak of cockroaches was between June and October. Infestation situation of cockroaches in farm produce trade market was the most serious, the others were restaurants, hotels, and so on. Conclusion The infestation of cockroaches was serious in farm produce trade market, restaurants, and hotels. The effective measures should be taken to prevent and control the cockroaches targeted.
Objective To monitor the rodent population distribution and its seasonality, and provide scientific evidence for controlling the infestation of rat and rodent destruction. Methods Adopting night trapping method and chosing medium mouse trap which specifications for 120 mm×65 mm, with fresh dough as bait. The mouse traps were placed along the wall base indoor and a certain terrains outdoor. Laying mouse traps in the monitoring sites of same areas at adjacent month were not allowed. Monitored once in the mid-month, rainy day does not monitor, laying mouse traps at night and recoverying at daytime. Count the numbers of effective mouse trap and mouse. Finally, calculate the rat density. Results A total of 254 rodents were captured from 2008 to 2012, with a mean density of 1.26%. Of all rodents, the dominant species was Rattus flavipectus (67.32%). The rodent density followed a double-peak curve, with the first peak in March and the second peak in September and October. The density of rodents was the highest in the key units, followed by general unit, residential indoor and outdoor environments. Conclusion For the rodents in Changning, their community composition and seasonal density fluctuation are acquired. It is suggested to take integrated rodent control measures and enhance long-term monitoring, early warning, and prevention of rodents and rodent-borne diseases according to the habits and characteristics of rodents and their seasonal density fluctuations.
Objective To determine the species composition and seasonality of mosquitoes in different environments from 2012 to 2014, and to provide the scientific basis for the prevention and control of mosquitoes and mosquito-borne diseases. Methods The adult mosquito surveillance data by light trap method were collected from four districts, then the densities of different environments, months, and years was analyzed. Results From 2012 to 2014, 15 549 mosquitoes were captured and the overall average density was 1.79 mosquitoes per hour. Culex pipiens quinquefasciatus Say was the predominant species, accounted for 83.46%. The annual density peak was observed in July in 2012; duel annual peaks were observed in 2013 (April and September) and 2014 (March and October). In different environments, the density in livestock shed (2.40) was the highest in 2014 while that in farmyard (3.14) in 2013. Conclusion In general, ecological habitats observed in Haikou city, Hainan, China were highly conducive to mosquito proliferation. The predominant species is Cx. pipiens quinquefasciatus. And the livestock shed and the farmyard are the key sites where the main control efforts should be made. The key period of mosquito eradication is from March to October during a year.
This paper describes the current status of resistance in insects to spinosad, and summarizes spinosad resistance mechanism from the aspects of physiological and biochemical mechanism, as well as molecular implication. The resistance mechanism of insects to spinosad, however, remains unclear. It is very important to study the mechanism and delay the insects'development of resistance to spinosad.
