Objective To study the taxonomy of the genus Haemolaelaps from China. Methods The study was conducted by the morphological taxonomy and comparative morphology of the organism. Results Twenty-three species of the genus Haemolaelaps from China were recorded, and a new key to the species of the genus Haemolaelaps was established. Conclusion This study provides the baseline data for the distribution and classification of the genus Haemolaelaps from China.

【Abstract】 Objective To understand the pattern of epidemic areas of hemorrhagic fever with renal syndrome (HFRS) in Fujian and to provide scientific basis for its prevention and control.  Methods Rats were captured in springs and autumns by live snap method, and its density and specie composition were investigated. The virus antigen from rodent lungs was isolated and identified. Results The dominant species in residential areas was Rattus norvegicus in Rattus type areas and the mixed?type area, which density were 4.91% and 5.73% at home respectively. While in the field, it was Apodemus agrarius with the average density of 12.95%, which was obviously higher in autumn and winter than that in spring. R.norvegicus mainly carried with Type Ⅱ virus, and Ap.agrarius with Type Ⅰvirus. A44 and R50 virus strain were isolated from them, respectively. Conclusion R.norvegicus was still the main host of HFRS in Fujian. Ap.agrarius was the main host in the field in the diversity epidemic area. It should strengthen the surveillance and the control of HFRS in main epidemic areas.

Objective To investigate the distribution of gamasid mites and chigger mites on rodents in Sanduao island of Fujian.Methods Rodents were captured alive with cages,and the mites parasitized on the rodent were collected and identified.Results 6769 gamasid mites collected belonged to 4 family,8 genus and 13 species,and 31 580 chigger mites collected belonged to 1 family,2 genus and 6 species.The density of gamasid mites parasitized on Niniventer fulvescens was the highest,and the dominant mite species were Laelaps turkestanicus and L.fukienensis.The infested rate and the infested index of chigger mites to Rattus rattoides and N.fulvescens was all higher,and the dominant species parasitized on R.rattoides was Leptotrombidium scutellare and that on N.fulvescens was L.pallidum.The infested rate of gamadis mites to R.rattoides in bushes and mountainous regions was 86.67% and the infested index was 9.99,which were higher compared to the infested rate of 68.57% and the infested index of 6.86 in paddy fields.The infested rate of chigger mite to R.rattoides in bushes and mountainous was 93.14% and the infested index was 128.30,which were higher compared to the infested rate of 36.90% and the infested index of 29.03 in paddy fields. L.echidninus and L.nuttalli appeared in the whole year without obvious seasonal changes. L.fukienensis, L.turkestanicus, L.scutellare, L.pallidum,Doloisia guangdongensis and L.allosetnm were all active in winter and spring while Haemolaelaps chinensis only appeared in winter,and L.deliense appeared in summer and autumn when the temperature was comparatively higher.Conclusion 13 species of gamasid mites and 6 species of chigger mites were found on the rodents in Sanduao island,and the changes of species composition and population density was affected by host,habitats and seasons.

The toxicity and killing efficiency of Bromethallin were investigated against three species of rodents in Fujian during April to July, 1994. The results showed that the LD ₅₀ were 1.801±0.233mg/kg for Rattus norvegicus,3.292±0.421mg/kg for Rattus flavipectus and 11.003±1.431mg/kg for Mus musculus, respectively.The feeding coefficient of the rice bait ( 0.01% Bromethallin) was 1.75.Its killing ratioes appeared to be 100% against R,flavipectus in laboratory test and 89.96% against R,norvegicus in field test.

This paper reported the comparative study on four kinds of investigating methods for rodent population density,powdered-spot,bait expending,clip-trap capture as well as cagetrap capture.Correlation and regression analysis were engaged between the data obtained by different methods.There were great difference among different methods for determining the killing efficiency of rodenticide,which would be in verse proportion to the susceptibility of the investigating method.The repercussions of domestic rodents to the long-term traping and the suitability for different investigating methods was also discussed.