Objective To determine the host selection and distribution of Ascoschoengastia indica on different small mammal hosts in different areas of Yunnan province. Methods A field survey was carried out in 19 counties of Yunnan province. The small mammal hosts were captured with mice cages and traps with baits. The chigger mites on the surface of two auricles were scraped off by a bistoury and then preserved in 70% ethanol. Species of each specimen of the chigger mites was identified using microscopy. Conventional statistical Methods were adopted to calculate the constituent ratios of A. indica on different hosts and in different areas, together with its prevalence and mean abundance on different hosts. Results A total of 1267 individuals of A. indica (1.36% of the total chigger mite species) were collected from the body surface of 3224 individual small mammal hosts of 7 species. The host specificity of A. indica was relatively high compared to that of other species of chigger mites, of which 94.40% were collected from the body surface of Rattus tanezumi. Conclusion The A. indica species are mainly distributed in southern and midwestern Yunnan with a high abundance, mostly on the body surface of R. tanezumi, a major reservoir host of tsutsugamushi disease.

Objective To determine the niche breadth and overlap in eleven dominant species of gamasid mites parasitic on 39 species of small?mammal hosts around Biluoxueshan Mountain in Weixi, Yunnan. Methods The niche breadth was determine using the Levins model, the niche overlap the Colwell?Futuyma model, based on which the systematic grouping of niche overlap for all gamasid mites was completed by cluster analysis. Results （1） Eulaelaps huzhuensis and Hypoaspis pavlovskii had the widest niche breadth (0.1067 and 0.1044), while Laclaps traubi Domrow and Haemogamasus sanxiaensis had the narrowest (0.0390  and  0.0365). （2）L. traubi  Domrow  and  L. turkestanicus  shared  a  highly  similar  population  distribution  with  L. chin, Ha. oliviformis and Hy. pavlovskii. Conclusion The niche breadth could be used as an index for evaluating the host specificity of gamasid mites, whose similarity in population distribution was largely related to that of their hosts, as well as their taxonomic distance.

【Abstract】 Objective To investigate the geographical distribution, habitat, dominant hosts and population spatial distribution patterns of Ornithonyssus bacoti in Yunnan province.  Methods   A total of 28 counties in five zoogeographical sub?regions were chosen as the investigated sites. Each investigated site was divided into two habitats (indoors and outdoors) and then small mammal hosts were randomly captured by mouse traps. All the gamasid mites from the body surface of the hosts were collected and preserved in 70% ethanol. Hoyer’s medium was used to mount the mites onto glass slides and each mite specimen was finally identified by microscope. The spatial pattern of the mite was analyzed by K?value of negative binomial distribution, patchiness index, Taylor’s power function and Iwao’s model.  Results A total of 3339 O. bacoti were collected from 11 560 captured  small  mammal  hosts  which belonged to 3 orders 4 families 8 genera  and  15  species.  Of  the  investigated 28 counties, O. bacoti was found in 21 counties and the mites were collected from 15 species of small mammal hosts. O.bacoti mainly distributed in Southwest region (accounted for 90% of the total), and the quantity of O. bacoti in indoors (2914, 87.27%) were obviously higher than that in outdoors (425, 12.73%).  90% mites mainly parasitized on the body surface of Rattus norvegicus and R. tanezumi which were  the  dominant  host  of  mites.  The  results  showed  that  the  spatial  pattern  of  O. bacoti  was  an  aggregated  distribution. Conclusion O. bacoti  widely  distributes  in  Yunnan  province  and  mainly  parasitizes  on  the  body surface of R. norvegicus and R. tanezumi. It is of aggregated distribution among its main hosts.

【Abstract】 Objective To investigate the community structure of fleas on small mammals in eight counties of southern mountainous areas in Yunnan. Methods Small mammal hosts were captured from eight counties selected randomly in southern mountainous areas and fleas were collected from the body surface of each host. Richness (S), Shannon?Wiener’s diversity index (H′), evenness (J′) and dominance index (C′) were used to measure the community structure of fleas on the hosts. Results There were 3184 small mammals captured, which belonged to 21 species,13 genera, 5 families and 4 orders. A total of 1767 fleas were collected from the small mammal hosts and were classified into 15 species, 13 genera and 5 families. There were seven dominant small mammals like Rattus tanezumi, Mus caroli, M.pahari, R.norvegicus, Suncus murinus, R.rattus sladeni and Niniventer fulvescens, and the dominant fleas were Xenopsylla cheopis, Nosopsyllus (Nosopsyllus) wualis and Leptopsylla segnis. Conclusion There are few fleas in the southern mountainous areas of Yunnan which biodiversity is lower than that in others.

【Abstract】 Objective To understand the ectoparasite communities in a population of Eothenomys miletus in the surrounding areas of Erhai Lake and describe the importance of them in the medicinel and veterinary. Methods Investigation sites were randomly selected at different direction of surrounding areas of Erhai Lake in Yunnnan. Small mammals were captured by live traps with baits. The live traps were examined and the baits were changed each morning. Trapped small mammals were brought to the laboratory to identify according to their body shape, size and color, and some measurements such as body length, ear length and hind feet length, and ectoparasites were collected. Ectoparasites were identified under a microscope after mounting, clearity and desiccation. The constituent ratio (C), prevalence (P) and average ectoparasite abundance (A) were used to reflect the prevalence and density of ectoparasites. Non-parametric Mann-Whitney U-tests were used to test differences in the abundance and richness of ectoparasites between female and male hosts. Spearman correlation analysis was used to analyze the relationship between ectoparasites and the body parameters of hosts. Results There were 916 E.miletus caught. Of which, a total of 756 were infested by ectoparasite, and the infestation rate was 83%. A total of 86 species of ectoparasite were collected, including 51 species of chigger mite, 23 species of gamasid mite, 7 species of flea and 5 species of sucking louse. Seventeen species were proved to be the main vectors of human disease. Conclusion There was very high diversity of ectoparasites parasitized on E.miletus, and some species had been reported to be associated with human disease. E.miletus could be a natural reservoir of plague bacilli, epidemic haemorrhagic fever (korean haemorrhagic fever) viruses and scrub typhus.

【Abstract】 Objective To illustrate the similarity， transitional tendency and classification of gamasid mite communities in the surrounding areas of Biluoxueshan in Weixi county of Yunnan province. Methods System clustering analysis was used in this study. Results In 1560 small mammals captured， the dominant species of mites from Apodemus draco， Eothenomys miletus， Niviventer confucianus， Ap.chevrieri, Ap.peninsulae, Rattus norvegicus and R.tanezumi were Laelaps jingdongensis（Dr＝41.32）, L.chin（Dr＝41.87）,  L.traubi （Dr＝63.51） and L.turkestanicus （Dr＝24.78）, L.traubi（Dr＝18.82）,  Eulaelaps huzhuensis（Dr＝14.11） and L.chin（Dr＝11.76）, E.huzhuensis（Dr＝25.00）, E.huzhuensis（Dr＝23.61） and Haemogamasus oliviformis（Dr＝16.67）, Ornithonyssus bacoti（Dr＝71.73） and O.bacoti（Dr＝98.82）, respectively. The result of system clustering analysis indicated that there was prominent similarity between the gamasid mite from R.norvegicus and R.tanezumi, secondly it was the similarity among the mites from Ap.draco, Ap.peninsulae and Ap.chevrieri. Conclusion  The taxonomic relations of mite hosts was nearer, the communities similarity of gamasid mite was higher. The habits distribution of hosts had an effect on communities type of parasitic gamasid mite.

【Abstract】 Objective To study the distribution and its ecological charateristics of medical gamasid mites in the surrounding areas of Biluoxueshan in Yunnan province, China. Methods Some small mammals were captured by mouse traps (or mouse clips) in the surrounding areas of Biluo snow mountain located in Weixi county of Yunnan province. The ectoparasitic gamasid mites were all collected from the body surface of small mammal hosts. The community structure of gamasid mites were illustrated with richness （S）, Shannon?Wiener’s diversity index（H′）, evenness（J′） and dominance index（C′）. The spatial distribution patterns of some dominant species of gamasid mites were measured by disperse coefficient, clumping index, Cassie index and patch index. Results There were 1560 small mammals belonging to 40 species captured, and 35 species of gamasid mites were collected from the body of small mammals. Of which, 8 species were not identified. The community of gamasid mites showed a high diversity with abundant species. The dominant species of gamasid mite were Laclaps traubi, Laelaps chin, Laelaps jingdongensis, Laclaps turkestanicus and Ornithonyssus bacoti. The distribution patterns of 5 dominant gamasid mite species on the body of small mammals were of aggregated distribution. Of the 5 dominant species, the female ratios of most mite species （96.84%, 87.94%, 92.78%, 95.77%） were much higher than the males, but Os.bacoti was an exception （37.25%）. For most mites species, the proportion of the larvae and nympha was much lower with the exception of Os.bacoti Hirst （54.51%）. Conclusion The community of gamasid mites in the surrounding areas of Biluo snow mountain was relatively complicated with abundant species. The spatial distribution of dominant mite species was of aggregated distribution pattern.

Objective To investigate the basic information of sucking lice on the body surface of Eothenomys miletus (a dominant species of wild rats in Yunnan), including the louse species constitution and distribution, the dominant species of louse and their spatial pattern, the sex ratio and the community structure, etc. Methods E.miletus (the host of lice) was captured alive with a mouse trap in 17 counties (or towns) of Yunnan. All the lice on the body surface of the hosts were completely collected. Richness( S), diversity index( H′), evenness( J′) and dominance index( C′) were used to illustrate the community structure of sucking lice on the hosts according to Shannon-Wiener's method. Disperse coefficient( C), Cassie index( C_A), clumping index(I) and patch index(m/m) were adopted to measure the spatial distribution pattern of sucking lice. Results 1169 individuals of E.miletus were captured only in five counties (towns). Only six species of sucking lice (3528 individuals) were collected from the body surface of 1169 rats hosts (E.miletus). Both the richness and diversity index of sucking louse were very low. Hoplopleura edentula was the dominant species with 99.46% of relative dominance(D_r). The dominant louse species, H.edentula, showed an aggregation spatial distribution among the different individuals of the rat host. Male and female adults of H.edentula accounted for 81.62% of the whole development stages. The sex ratio of female/male in the dominant louse species was 1.53. Conclusion The sucking louse variety on E.miletus is very singularity and its community structure is also very simple. The distribution of H.edentula, a dominant louse species on E.miletus, is an aggregation pattern with more female adults.

Objective To understand the species distribution of ectoparasitic chigger communities on small mammals in Yunnan province. Methods Mammals (the host of chiggers) were captured with mouse cage traps and bait in 16 counties (or cities) of Yunnan province. All the chiggers on two auricles of the hosts were made into specimens with Hoyer's medium and all the specimens were identified under microscope. Preston's lognormal distribution model was used to fit the species abundance. Results 6888 small mammal hosts were captured and 192 chigger species were collected, which belong to 21 genera, 3 subfamily of Trombiculidae. Leptotrombidium scutellare and L.sinicum were dominant chigger species. The species abundance distribution of chigger mites is successfully fitted to Preston's lognormal distribution model with the goodness of fit of 0.7975. Conclusion The species abundance distribution of chiggers on small mammals conforms to the lognormal distribution. Most chiggers species are the common species with middle levels of individuals, rare species take second place, while few species are dominant quantitatively.

Objective To investigate the community structure of fleas on Eothenomys miletus, together with the distribution of species-abundance and the relation of species-plots. Methods 19 counties (towns) in Yunnan province of China were selected as investigation spots. Flea specimens were collected from the body surface of every rodent. Every flea was finally identified into species under a microscope. All the fleas on Eothenomys miletus were defined as one community unit. Richness( S), Shannon-Wiener's diversity index( H′), evenness( J′) and dominance index( C′) were adopted to measure the community structure of fleas. Results 2248 fleas were collected from the body surface of 1295 rodents ( Eothenomys miletus). All the fleas were identified as 10 species belong to 7 genera of 3 families. Of 10 flea species, 2 main flea species accounts for 96.66% of the total specimens. The distribution of species-abundance shows that there are 3 species with only one individual and the individuals of 2, 4, 5, 16, 45, 121 and 2052 correspond to only one species in the flea community. The species-plot relationship shows that flea species increase with the increase of mouse plots(samples). Conclusion Eothenomys miletus can host several species of fleas, but most flea species are rare ones and they have not established a stable parasitic relationship with their host. Few flea species are dominant ones with abundant individuals.

Objective To understand species composition of gamasid mites on the body surface of Rattus flavipectus(a dominant species of domestic rats in Yunnan,China) and species diversity.Methods Twenty-five counties(towns) in Yunnan province were chosen to investigate the ectoparasitic gamasid mites on the body surface of R.flavipectus.All the individuals of R.flavipectus were randomly captured by mouse-traps and the gamasid mites on the body surface of R.flavipectus were all collected.Every individual of the gamasid mites was mounted on a glass slide after the dehydration and clarification in a conventional way.The mounted specimens of the gamasid mites were finally identified under a microscope.Results(18 250) gamasid mites were collected from the body surface of(3765) captured rats R.flavipectus and all the mites were identified as 40 species of 17 genera in 9 families.Of the 40 species of gamasid mites,three gamasid mite species(Laelaps nuttalli, L.echidninus and O.rnithonyssus bacoti were the dominants. L.nuttalinushas(10 667) individuals collected((58.45%)) while L.echidninus (5124)((28.08%)) and O.bacoti(1286)((7.05%)).37 species of gamasid mites are found in the southwest mountainous subregion in zoogeography with three dominant species, L.nuttalli((51.74%)), L.echidninus((29.74%)) and O.bacoti((11.40%)).In comparison with the species in the southwest mountainous subregion of Yunnan,less species of the mites(25 species) are collected in the southern mountainous subregion of Yunnan with two dominant mite species, L.nuttalli((64.35%)) and L.echidninus((26.61%)).Conclusion The ectoparasitic gamasid mite species on R.flavipectus in Yunnan province are very abundant and the species compositions of the gamasid mites are different in different zoogeographical regions.