Objective To investigate the mixed densities and activity patterns of mosquitoes in three different types of pig farms in the central and western parts of Hainan province, China, and construct the basic data of mosquito activity in pig farms, and to provide a reference for scientific control and prevention of mosquitoes. Methods Mosquitoes were monitored by the lamp trap method, animal-bait net trap method, and pig sty landing mosquito collection method. Excel 2010 software and SPSS 26 software were used to process the number of mosquitoes to analyze the seasonal fluctuations of mosquitoes in different types of pig farms, the diurnal and nocturnal activity pattern of mosquitoes in the farmer’s backyard pig sty, and the landing index of mosquitoes in the traditional pig farm. The Pearson’s chi-squared test was used to compare mosquito composition between different types of pig farms. Results The annual average density of mosquitoes was (4.79±4.32) mosquitoes/lamp·hour in the farmer’s backyard pig sty, (15.31±16.51) mosquitoes/lamp·hour in the traditional pig farm, and (15.16±11.20) mosquitoes/lamp·hour in the modern pig farm. The mosquitoes mainly involved 5 species of 5 genera in any of the three pig farms. Culex tritaeniorhynchus was the dominant species in all the three pig farms, with the composition ratios of 70.33%, 89.64%, and 93.95%, respectively. There was a statistical difference in the proportion of the major mosquito species between the three pig farms ( χ ²=8 410.560, P<0.001). The seasonal fluctuation of mosquitoes differed between the three farms, presenting as a single-peak pattern, a wavy pattern, and a double-peak pattern, respectively, with the activity of mosquitoes peaked in October, November, and July and September, respectively. In the farmer’s backyard pig sty, mosquitoes showed a diurnal-nocturnal activity pattern of double peaks in the morning and evening. The average landing index of mosquitoes reached up to (154.50±30.71) mosquitoes/pig·hour in the traditional pig farm. Conclusion All the three types of pig farms have relatively high mosquito densities. They have distinct compositions of major mosquito species and seasonal fluctuations of mosquitoes. Mosquito prevention and control should be carried out scientifically according to the mosquito activity pattern of the pig farm.

In order to further get the mosquito fauna in Qinghai province, China, a survey of mosquito larvae breeding sites was conducted in Ledu county, Qinghai province from August to September 2018. Specimens of mosquito larvae were collected, and were made into pinned specimens for morphological taxonomic identification after they were reared to adults. In this investigation, Culex ( Culex) vagans Wiedemann, 1828 was found among the mosquito specimens collected from the rural household water storage tanks and the river ditches in Ledu county. Culex vagans was firstly recorded in Qinghai province, China.

Objective To identify the Borrelia burgdorferi in Glires in Huzhu, Zekog, and Qilian county, Qinghai province. Methods A total of 202 Glires were collected from forest in the counties, Qinghai province. All the collected samples were examined for B. burgdorferi by nested PCR. Results In total of 202 samples, 49 samples were tested positive by 24.26%. Positive rate was 17.91% (12/67) in Huzhu county, 34.62% (27/78) in Zekog county and 17.54% (10/57) in Qilian county. There was significant difference with positive rate of B. burgdorferi in Glires among these three counties(χ²=7.40, P<0.05). Conclusion Our research confirmed the existence of B. burgdorferi in Glires in three counties in Qinghai province. We suggested that the further investigation on local vectors and human infections be conducted for prevention and control of Lyme disease.

Objective To study the relationship between vegetation attributes and distribution of Oncomelania hupensis on the beach of Qingyi River. Methods Using a combination of random sampling and systematic sampling, an investigation was conducted on the vegetation and O. hupensis in the quadrats on the beach of Qingyi River to determine the species, cluster number, phenological period, viability, height, coverage, abundance, and frequency of vegetation as well as the total number of snails, number of living snails, and number of dead snails. Results There were 12 major species of vegetation on the river beach, including Alternanthera philoxeroides, Cynodon dactylon (Linn.) Pers., Cyperus microiria, Torilis scabra (Thunb.) DC., Artemisia lavandulaefolia DC., Dendranthema indicum (L.) Des Moul., Xanthium sibiricum, Rhizoma cyperi, Humulus scandens (Lour.) Merr., Juncus effusus, Glycine soja Sieb. et Zucc., and Polygonum flaccidum Meissn.; A. philoxeroides and Rhizoma cyperi were the dominant species. The density of living snails was the highest in the A. philoxeroides cluster (2.67 living snails/0.1 m²), and the density of dead snails was the highest in the C. dactylon/P. flaccidum cluster (2.33 dead snails/0.1 m²). The regression analysis of vegetation coverage and O. hupensis density produced the following quadratic functions: y=11.435+2.104x-0.162x² (R²=0.394,F=42.319,P<0.01) (summer); y=14.154+1.034x-0.043x² (R²=0.794,F=57.432,P<0.01) (autumn). Conclusion O. hupensis has a tendency toward the A. philoxeroides cluster, and the C. dactylon/P. flaccidum cluster may have a molluscicidal effect on O. hupensis. The relationship between coverage of vegetation and density of O. hupensis can be reflected by quadratic functions.

【Abstract】 Objective To understand the epidemic situation of Lyme disease and its distribution in Qinghai, and to collect the information on main vectors and main host carrying bacterium. Understand the infection level of Lyme disease to human and provide the evidence for the surveillance and control of it. Methods Lyme disease leptospira were tested by PCR, and blood serum antibody (lgG) were determined by immunfluorescence (IFA). Results A total of 1108 people were investigated, and 167 cases were positive, the average infection rate was 15.07%. The people’s average infection rate was 7.98% in the forest areas, and  21.21% in the farming. There was significant difference between them (χ2＝36.68, P＜0.001). However, there was no significant difference among different gender and age groups. The main vector was Qinghai blood tick, and the rate carrying bacterium was 23.93%. The main host was the house mouse accounting for 46.08%, which the rate of carrying bacterium was 20.59%. Conclusion Not only the infection of Lyme disease is higher, but also the infection rate is also higher in the population. The average infection level is higher than nation average level. The infection situation varies greatly in different areas because of the difference of ecologic environment, production manner and living habit. The average infection rate in the farmland is obvious higher than that in pasture areas. Qinghai blood tick is the important vector, and there is a Lyme natural foci in Qinghai.