Objective To investigate the population, community dominance, diversity, homogeneity and geographical niche of mosquitoes in China-Laos border, so as to provide advices for the prevention and control arboviral diseases and establish a reference for related ecological researches in these districts. Methods Surveillance were conducted in 12 counties and cities in China and Laos around border from 2012 to 2015. Adult mosquitoes were collected by overnight trapping with ovitrap light from August to October of each year. All captured mosquitoes were counted and identified in the laboratory and then computed the community composition, density, community index and geographical niche of mosquitoes. Results Total of 26 061 adult mosquitoes was captured and identified to 58 species of 13 genera in 3 subfamilies. Among them, 20 410 mosquitoes of 46 species of 11 genera in 3 subfamilies were captured in China and 5 651 mosquitoes of 36 species of 10 genera in 2 subfamilies were captured in Laos. The predominant species were Culex tritaeniorhynchus and Anopheles sinensis in the border areas of China and Laos. The proportion for Cx. tritaeniorhynchus in all captured mosquitoes were 52.05%(10 624/20 410)in China and 54.24%(3 065/5 651)in Laos( P>0.05). But the proportion of An. sinensis were higher in China(23.58%, 4 813/20 410)than in Laos(12.42%, 702/5 651)( P<0.05). There is no statistical significance in the average density between captured mosquitoes, Cx. tritaeniorhynchus and An. sinensis( P>0.05). There is no statistical significance in the dominance index, diversity index and homogeneity index( P>0.05). The order of mosquito diversity in counties along the border of China and Laos from high to low was Phongsaly, Louangphrabang, Luangnamtha, Houayxay, Oudomxay, Jinghong, Jiangcheng, Mengla, Mengxing, Simao, Menghai and Bengtai. The mosquitoes with maximum geographical niche were Cx. tritaeniorhynchus( B_i=0.810 9), Ar. subalbatus ( B_i=0.746 1)and An. kochi( B_i=0.742 6)of 12 counties in the border of China and Laos, An. sinensis( B_i=0.880 2), Cx. tritaeniorhynchus( B_i=0.875 1)and Ar. subalbatus( B_i=0.809 5)in 5 counties of China border and Ar. subalbatus ( B_i=0.944 7), Cx. tritaeniorhynchus( B_i=0.895 1), and An. barbirostris( B_i=0.880 8)in 7 counties of Laos border. Conclusion The populations of mosquitoes in the border of China and Laos were highly diverse, homogeneous distribution among communities, with stable composition and similar ecological characteristics. Culex tritaeniorhynchus and An. sinensis were the predominant species with maximum composition of community, density and geographical niche in these districts.

Objective To investigate mosquito species in Muangsing county of Luangmamtha province, Lao PDR, providing evident for local important arbovirus infectious diseases. Methods Adult mosquitoes were collected by light-traps method overnight, and 4^th instar larvae were collected from different mosquito breeding sites, identifying them by morphological classification method. Results A total of 21 781 mosquito individuals were collected from 44 species in 11 genera, of those Culex tritaeniorhynchus and Anopheles sinensis belonged to local predominant adult species, their proportions were 54.39% and 39.28% of total collected adult mosquito respectively; 4^th instar larvae rates of Armigeres flavus and Cx. mimeticus were higher than the others, their rates were 43.42% and 18.86% of total collected Ⅳ-larvae respectively. Conclusion Mosquito species were very rich in Muangsing county of Luangmamtha province, Lao PDR, and Cx. tritaeniorhynchus and An. sinensis belonged to local predominant mosquito species, the results hinted local health department should strengthen mosquito-borne infectious diseases monitoring.

Objective To investigate the distribution of Aedes albopictus in the central city of Yuxi, providing scientific basis for prevention and control of dengue fever. Methods Mosquito larvae were captured indoor and outdoor water containers from north, south, west, east and central residential areas and special places in the central city; adult mosquito was collected by human landing collection and whole site at special places; and dengue virus was tested by specific nucleic acid detection for Ae. albopictus adult mosquitoes. Results Aedes albopictus was found in 3 villages at the north of the city and 1 residential area at the west of the city,the total container index(CI) was 0.37. In the east, south and center of the city, no Ae. albopictus was found. Total of 2 193 individuals of 7 species were collected from a waste tire processing factory and a salvage station in the north and west of the city, and Ae. albopictus accounted for 82.44%(1 808/2 193); the CI of larvae was 5.21, Breteau index reached up to 60.00 at waste tire processing factory in the north of the city. No dengue virus was detected in Ae. albopictus adult mosquitoes. Conclusion It was the first time found Ae. albopictus in the central city of Yuxi, and its density was high, it's hinted that there is a risk of dengue transmission and epidemic, and the attention should be paid by the relevant health departments.

Objective To investigate mosquito fauna and habitats in the north of Laos and provide evidences for clarification of mosquitoes, prevention of mosquitoes borne diseases and take advantage of biological resources. Methods Seven counties of five provinces in the north of Laos were chosen randomly from August to October in 2014 and 2015. Adult mosquitoes were collected by overnight trapping with ovitrap light and larvae were collected in the different breeding sites. All captured mosquitoes were processed in the lab. Results In total, 5 921 adult mosquitoes and 3 526 larvae were collected from 82 species of 19 subgenera of 15 genera in 3 subfamilies. All captured adult mosquitoes from 37 species of 11 subgenera of 10 genera in 2 subfamilies were collected by overnight trapping with ovitrap light. The predominant species was Culex tritaeniorhynchus(3 925, 66.29%). Besides, collected larvae belonged to 59 species of 17 subgenera of 12 genera in 3 subfamilies. Culex tritaeniorhynchus was still the predominant species(751, 21.30%). In total, 636 larval habitats of seven different environments were investigated. The predominant habitats were bamboo tube and tree hole(162) and wasted tires(153), these three habitats accounted for 49.30%(315/636)in all habitats. Conclusion The mosquito species showed biological richness in the north of Laos. The predominant species was Cx. tritaeniorhynchus, followed by Anopheles argyropus, An. minimus, An. sinensis, Aedes albopictus, Armigeres subalbatus and Ae. aegypti. The diversity and complexity of habitats of larvae were observed. Different mosquito larvae preferred different habitats, but symbiotic phenomenon of various mosquito species commonly existed.

Objective To study species distribution, community composition and bloodsucking rate of hematophagous midges in 3 cities (countries) of China-Laos border. Methods Hematophagous midges were captured with light trap to generate data on the species distribution in China-Laos border in June to August, 2015. Results A total of 78 336 host-seeking midges belonging to 54 species and 3 genera were collected; genus Leptoconops with 4 species, genus Lasiohelea with 7 species, genus Culicoedes with 43 species. Seven species, C. gentiloides, C. huffi, C. kibabaluensis, C. lansangensis, C. parahumeralis, C. variatus, La. adita are recorded for the first time in Yunnan province. The species distribution of hematophagous midges was recorded 48 species in Mengla, 22 species in Jiangcheng, 16 species in Jinghong. The predominant species included C. jacobsoni, C. parahumeralis and C. palpifer, and their composition were 25.93%, 19.25%, and 17.13% respectively. The community composition and the bloodsucking rate of midges varied with different counties and habitats. The bloodsucking rate was 32.26% in residence district, and 28.24% in cowshed. Conclusion The investigation provides the reference for species distribution, community composition and studies of infectious disease by hematophagous Culicoides.

Objective To understand the epidemiological characteristics of imported dengue cases in Yunnan during 2004-2014, and provide the scientific information for the effective strategies of dengue control and prevention. Methods The data of imported dengue cases were collected from China Information System for Diseases Control and Prevention during 2004 to 2014. A database was established to analyze the epidemiological characteristics with method of descriptive epidemiology; dengue serotype was detected by RT-PCR.Results From 2004 to 2014, a total of imported cases were 629 (629/2 192, 28.70%) in Yunnan; The imported cases of dengue were mainly reported in Dehong Prefecture (341 cases), Xishuangbanna Prefecture (159 cases) and Kunming city (108 cases); The cases were reported every month, but 85.37% (537/629) of the cases were imported between August and November. Male cases were much more than female, 419 and 210 cases respectively. The occupations of cases mainly were business service people (165 cases), farmers (134 cases) and students (72 cases). Most cases were imported from Myanmar (403 cases) and Laos (132 cases). Four (4) dengue serotypes were found from imported cases; of those DEN-3 was the major type in those from Laos, and DEN-1 in those from Myanmar. Conclusion The imported dengue cases have been on rise in Yunnan, and their major concerns are the border areas with Laos and Myanmar. The above results suggested that colloborative efforts from various agencies should be strengthened to monitor border imported dengue cases in case of dengue outbreak.

Objective To analyze the genotypes and E gene sequence characteristics of 13 Japanese encephalitis virus(JEV) strains isolated from mosquitoes in Lancang River watershed in Yunnan province, China during 2007-2009. Methods E genes of 13 JEV strains were amplified by RT-PCR. The nucleotide similarity and amino acid homology were analyzed by MegAlign program in DNAStar software. Multiple sequence alignment and phylogenetic analysis were carried out using Clustal X 1.83 and the Mega 5.0. Results The nucleotide similarity and amino acid homology among the 13 JEV strains were 98.0%-100% and 99.8%-100% , respectively. Compared with the live attenuated vaccine strain (SA-14-14-2), the 13 JEV strains showed nucleotide similarity and amino acid homology of 86.1%-86.9% and 96.8%-97.2%, respectively. Phylogenetic analysis showed that the 13 JEV strains were genotypeⅠ. Conclusion The 13 JEV strains isolated from mosquitoes in Lancang River watershed in Yunnan province, China during 2007-2009 belonged to genotypeⅠ.

Objective To identify the isolated virus (ML-13) from mosquitoes in Yunnan province, China by molecular biology techniques. Methods The new virus isolate (ML-13) was amplified by C6/36 cells. The viral gene was amplified and sequenced using several sets of arbovirus primers. A phylogenetic tree was constructed using Mega 5.0 based on deduced amino acid sequences. Results ML-13 virus could be amplified in C6/36 cells. Target products were obtained by amplification using specific primers for Omono River virus (OMRV) and Tianjin Totivirus (ToV-TJ). ML-13 virus showed the highest sequence similarities (76%, 75%, 72%, 67%, and 67%) with OMRV-AK4, ToV-TJ, OMRV-Y61, DTV, and AsTV with regard to capsid protein (CP) and RNA-dependent RNA polymerase (RdRp). The phylogenetic analysis showed that ML-13 was in the same branch as OMRV, ToV-TJ, and DTV in Totiviridae family. Conclusion ML-13 strain isolated from Culex tritaeniorhynchus in Yunnan province, China belongs to the Totiviridae family and is the first isolate of Totivirus from Cx. tritaeniorhynchus in China.

Objective To investigate the species composition, ecological habitats and the natural infection of the dengue vectors in Menglian and Lancang counties bordered with Myanmar in Yunnan province, so as to provide evidence for the prevention and control of dengue fever. Methods Three villages in Menglian and Lancang counties were selected as surveillance sites. Adult mosquitoes were captured by human-landing catches and Aedes mosquito larvae were collected from various types of indoor and outdoor water containers in the three surveillance sites. Dengue virus in mosquitoes was detected by RT-PCR. Results A total of 3436 individual adult female mosquitoes of 22 species from 8 subgenus in 6 genus were collected from three sites in Menglian and Lancang counties from June to October, 2010. Aedes albopictus was the predominant species in three sites, accounting for 33.82% of all captured mosquitoes. No Ae. aegypti mosquitoes were found in these field sites. The average house index (HI), container index (CI), breteau index (BI), and thousand-person index of Ae. albopictus was 19.3, 5.84, 30.3, and 68.5 respectively. The dominant Ae. albopictus breeding environments were thick bamboo tubes, amphora, and used tires, accounting for 34.1%, 27.5% and 17.6%, of positive water containers, respectively. The average population density of Ae. albopictus adults was 8.98 per person per hour. The density peaked in July and August. Dengue virus was not identified by RT-PCR from 29 batches of Ae. albopictus. Conclusion Local dengue fever surveillance should be strengthened due to high vector density and wide distribution of Ae. albopictus in these areas.

【Abstract】 Objective To find out the relationship between the mosquito diversity in residential areas and its geographical distribution pattern along the midstream and downstream areas of Lantsang. Methods CDC light?traps were used to collect mosquitoes in 9 residential areas of 5 counties along the Lantsang. Results A total of 4682 mosquitoes belonged to 28 species of 6 genus were collected. The results showed that the Shannon?Wiener’s diversity index （H′） had a negative correlation with latitudes（r＝-0.3219） and elevations（r＝-0.4238）. Conclusion In the residential areas of Lantsang, Culex tritaeniorhynchus was the dominant species,  Anopheles sinensis, Cx.annulus,  Armigeres subalbatus,  Cx.pipiens quinguefasciatus, An.splendidus and Cx.fuscocephala were the common species. The Shannon?Wiener’s diversity index （H′）   had the relationship with the latitudes and elevations.