Objective To study the resistance levels of mosquito larvae and adult insecticides of dengue transmission media in Dalian, Liaoning province, to provide scientific basis for the comprehensive prevention and control of Aedes albopictus. Methods The larvae and egg masses of Ae. albopictus were collected in the residential area of Dalian city from August to September 2017 and bred in the laboratory. The WHO recommended larvae dipping method and mosquito contact barrel method were employed in the bioassay. Results The resistance multiple of the larvae of Ae. albopictus to deltamethrin was 3.00, which was low resistance. The resistance multiples of the other four insecticides, such as β-cypermethrin, parathion, dichlorvos and permethrin were less than 3.00 and were sensitive. Aedes albopictus to malathion resistant population of adult primary (M), the mortality rate was 97.00%, of β-cypermethrin, permethrin and deltamethrin were sensitive group (S), mortality rates were 100%, 99.00%, and 98.00%. Conclusion Aedes albopictus in Dalian Liaoning province is low or sensitive to commonly used insecticides, which insecticides can be used for daily control of Ae. albopictus.

Objective To master the condition of rodent population distribution, seasonal fluctuation, rodent density for different habitats, and to provide a basis for developing rodent control strategies. Methods The rodents density was investigated by night trapping. Two types of monitoring points were chosen in town, one in residential and the other in special industry. Two types of monitoring points chosen in village were the rural and outside. Results Totally 1 059 319 traps were placed, 1 009 744 were effective, and 18 929 rodents were captured in Liaoning province from 2006 to 2015, the average rodent density was 1.87%. The density of rodents was lower in city(1.15%) than village(2.69%), and the highest was outside the village(3.39%), followed by inside the village(1.97%), special industry(1.32%) and residential community(0.97%). The density of rodents inside the village, in special industry and residential community were decreased, but that outside the village increased. Rattus norvegicus was predominant species in Liaoning province. The rodent constituent of R. norvegicus decreased, the rodent constituent of Apodemus agrarius and Mus musculus increased, the rodent constituent of Cricetulus barabensis and Tscherskia triton remained stable. In different habitats, R. norvegicus was predominant species inside the village, in special industry and residential community, Ap. agrarius was predominant species outside the village. The rodent constituent of R. norvegicus decreased in all those different habitats, M. musculus increased, Ap. agrarius outside the village increased, C. hamster and T. triton remained stable. Conclusion The density of rodents totally deceased from 2006 to 2015, but increased in recent years. The density of rodents was lower in city than village, the prevention and control for rodent density should focus on the rural areas. In different habitats,the rodent constituent of R. norvegicus decreased, M. musculus increased, Ap. agrarius outside the village increased. According to their characteristics of different habitats, comprehensive prevention measures should be taken to reduce the rodent density, for the purpose of controlling rodent-borne diseases.

Objective To detect the infection of Francisella and Francisella-like endosymbiont(FLEs)in Haemaphysalis longicornis from Liaoning province. Methods In July 2013, 357 H. longicornis collected in Liaoning province were divided into 38 groups, and cultured for Francisella tularensis. Detection of Francisella and FLEs was performed using nested polymerase chain reaction(PCR)assays based on the amplification of 16S rRNA. The PCR products amplified with target fragment were sequenced, and then their nucleotide sequences obtained were aligned and performed phylogenetic analysis with published sequences of Francisella and FLEs in GenBank. Results In the sequenced 13 groups of H. longicornis, 5 groups belonged to F. tularensis, other 8 to FLEs. It was calculated that the minimum carrying rate with F. tularensis in H. longicornis from Helan town was 2.12%. The phylogenetic analysis indicated that 5 groups were assigned to a clade of F. tularensis, and the rest 8 groups to main clade with FLEs. Conclusion The current work is the first detection of the infection of F. tularensi and FLEs in H. longicornis from Liaoning province, which serves a warning to the health department within the region to do further risk assessment on the emergence of tularemia.

Objective To investigate the population composition and seasonality of rodents and their density in different habitats in Liaoning province, China, and to provide a scientific reference for developing rodent control strategies. Methods Two types of monitoring points were chosen in cities (and towns), one type in residential area and the other in special industrial area. Additionally, two types of monitoring points were chosen in rural areas, one type in villages and the other out of villages. The density of rodents was monitored by night trapping. Results Totally 506 806 traps were set up in Liaoning province from 2009 to 2013. There were 485 792 effective traps, which captured 7548 rodents. The average density of rodents was estimated to be 1.55%, with a higher level in villages (2.25%) than in cities (0.93%). The density of rodents was highest in natural villages (2.25%), followed by special industrial areas (1.09%) and residential areas (0.78%) in cities. Seasonal fluctuations of rodent density in total, individual years, or different habitats followed a double-peak curve. Two peaks of rodent density occurred in April to May and in September to October, respectively. Rattus norvegicus was the dominant species of rodents in Liaoning province. Conclusion The density of commensal rodents in Liaoning province showed a slightly increasing trend from 2009 to 2013. Seasonality of rodent density followed a double-peak curve. The control of rodent density should focus on rural areas. According to their characteristics of seasonal fluctuations, comprehensive preventive measures should be taken to reduce the density of rodents in the two peak periods, in order to control rodent-borne diseases.

Objective To investigate the trends of Culex tritaeniorhynchus population dynamics in Liaoning province and to confirm that whether they carry Japanese encephalitis(JE)or not, which can support a scientific basis for establishing the strategy of prevention and control of Japanese encephalitis virus. Methods Culex tritaeniorhynchus, captureusing mosquito-lured lamp in 14 cities of Liaoning province during 2006-2013, were used to investigate the population composition and distribution and seasonality. Results Populations of Cx. tritaeniorhynchus in Liaoning province are mainly distributed in three cities, Dandong, Dalian and Panjin city, Dandong which has the highest distribution, the ratio of Culex is 78.43%, and the highest density is up to 780.20 Culex/(equipment·h) in 2007. In addition, Cx. tritaeniorhynchus were captured in Dalian, Panjin, Yingkou, Huludao and Jinzhou cities in different months. The highest density of Culex is appeared in September.Conclusion Culex mainly distributed in paddy growing areas of coastal cities in Liaoning province, including Dandong, Dalian, Panjin and Huludao;the most serious areas is Dandong city with the highest density and highest viral infection. In Lioaoning provience, there was a coincidence of early populations, high density and high JE infection. This phenomenon proves there is a relationship of Culex population trends and morbidity of JE, therefore, investigating the incidence of JE and the trends of Culex could not be ignored.

Objective To investigate the resistance of malaria vector Anopheles to five insecticides in Liaoning province, China and to provide a basis for prevention and control strategies. Methods The filter paper contact method for adult mosquitoes, as recommended by WHO, was used to measure the mortality of malaria vector Anopheles and its susceptibility to five insecticides. Results Malaria vector Anopheles had resistance to five insecticides in Donggang city of Dandong and Beizhen city of Jinzhou, and the lowest mortality was only 16.7%. In Dandong, Tieling, and Jinzhou, Anopheles mosquitoes also developed varying degrees of resistance to 4% DDT, 0.05% deltamethrin, and 0.05% beta-cypermethrin, with the highest mortality of 97.4%. The 0.1% propoxur had good lethal effect on malaria vector Anopheles in Zhen'an district of Dandong and Kaiyuan city of Tieling, and 0.75% permethrin had good lethal effect on Anopheles mosquitoes in the Zhen'an district, all leading to a mosquito mortality of 100%. Conclusion In some areas of Liaoning province, malaria vector Anopheles maintains high resistance to DDT, and it also has varying degrees of resistance to beta-cypermethrin and deltamethrin. Thus, it is necessary to properly use the insecticides for delaying the development of insecticide resistance. Malaria vector Anopheles is relatively sensitive to propoxur and permethrin, so the two can be applied as main insecticides for Anopheles control at present.

【Abstract】 Objective To study the distribution,species and faunal regions characteristics of siphonaptera in Liaoning province. Methods The principle and method of zoogeography were used in this study. Results Nuruer Tiger Mountain is the watershed of Daling river and the upstream of the Liaohe river. Because of its obstruction to warm air current, the climate on both side of watershed changed differently. It was found that the zone of   siphonaptera and host animals fauna elements changed through investigation, especially the quality change of a representative special species. So, it suggested that the boundary of Chinese zoogeographic fauna of Xinjiang and Inner Mongolia and East China region in northwest of Liaoning province was amended, and the siphonaptera area of Liaoning province was divided into 7 province and 6 states. Conclusion The fauna characteristics should not judge according to merely the fauna element and the change of representative special species, the unity of animals distribution and environment conditions also plays an important roles.