Analysis of gamasid mites (Acari: Mesostigmata) associated with the Asian house rat, Rattus tanezumi (Rodentia: Muridae) in Yunnan Province, Southwest China Li-Qin Huang, Xian-Guo Guo, John R. Speakman & Wen-Ge Dong Parasitology Research Founded as Zeitschrift für Parasitenkunde ISSN 0932-0113 Volume 112 Number 5 Parasitol Res (2013) 112:1967-1972 DOI 10.1007/s00436-013-3354-y 1 23 Your article is protected by copyright and all rights are held exclusively by Springer- Verlag Berlin Heidelberg. This e-offprint is for personal use only and shall not be self- archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com”. 1 23 Author's personal copy Parasitol Res (2013) 112:1967–1972 DOI 10.1007/s00436-013-3354-y ORIGINAL PAPER Analysis of gamasid mites (Acari: Mesostigmata) associated with the Asian house rat, Rattus tanezumi (Rodentia: Muridae) in Yunnan Province, Southwest China Li-Qin Huang & Xian-Guo Guo & John R. Speakman & Wen-Ge Dong Received: 14 June 2012 /Accepted: 14 February 2013 /Published online: 8 March 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract During a survey lasting from 1990 to 2008, we rats trapped indoors. The parameter K from the negative captured 4,113 Asian house rats, Rattus tanezumi Temminck binomial distribution was used to measure the spatial distri- 1844 (Rodentia: Muridae) from 28 counties of Yunnan bution patterns of the dominant mite species and revealed Province in Southwestern China. From these rats, a total that all the mites had an aggregated distribution among the of 19,304 gamasid mites (Acari: Mesostigmata) were col- rat hosts. Most mite species showed a predominantly lected and identified as comprising 50 different species. The female-biased population structure with many more females species diversity of gamasid mites from this single rat spe- than males. cies is higher than that reported previously from multiple hosts within a given geographical region. Of the 50 mite species, 31 species belonged to ectoparasites and 19 species belonged to free-living mites. The species diversity of the Introduction mites from rats trapped outdoors was much higher than from Gamasid mites (mesostigmatid mites) belong to the order : : (or suborder) Mesostigmata, subclass Acari in class L.-Q. Huang X.-G. Guo (*) W.-G. Dong Arachnida (Pan and Deng 1980; Deng et al. 1993). Some Vector Laboratory, Institute of Pathogens and Vectors, gamasid mites are ectoparasites while others are predatory Dali University (Branch of Key Laboratory ’ for Preventing and Controlling Plague of mites, nidicolous mites, or edaphic mites found in the hosts Yunnan Province), Dali, Yunnan 671000, China nests, soil, litter, and humus (Pan and Deng 1980; Radovsky e-mail: [email protected] 1985; Walter and Lindquist 1989; Skorupski and Luxton L.-Q. Huang 1998). Small mammals (especially rodents) are the most e-mail: [email protected] common hosts for ectoparasitic gamasid mites (Deng et al. W.-G. Dong 1993; Baker et al. 1956). Besides causing such disorders as e-mail: [email protected] mite dermatitis (Alexander 1984; Chung et al. 1998; Rosen et al. 2002; Heukelbach et al. 2005), some species of ecto- L.-Q. Huang School of Life and Medical Sciences, Xinyu University, Xinyu, parasitic gamasid mites are the transmitting vectors of Jiangxi 338004, China rickettsialpox and hemorrhagic fever with renal syndrome (HFRS) (Deng et al. 1993; Younis et al. 1995;Song1999; J. R. Speakman Huang and Guo 2010). Located in Southwestern China, Institute of Biological and Environmental Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Yunnan Province is an important focus of some zoonoses Aberdeen AB24 2TZ Scotland, UK and vector-borne diseases including HFRS. There have been e-mail: [email protected] several previous scientific papers concerning the species di- versity, host specificity, spatial pattern, and community simi- J. R. Speakman Institute of Genetics and Developmental Biology, Chinese larity of gamasid mites (Guo 1997, 1998,1999a, b;Korneev Academy of Sciences, Beijing, China 2002; Martins-Hatano et al. 2002; Korallo et al. 2007; Luo et Author's personal copy 1968 Parasitol Res (2013) 112:1967–1972 al. 2007; Vinarski et al. 2007), but few studies have and other instruments were cleaned with disposable paper addressed the gamasid mites associated with a single towels to reduce the chance of cross-contamination. species of rodents. Asian house rats, Rattus tanezumi According to the external morphology, measurements, Temminck 1844 (Muridae), (also called Rattus flavipectus and visible characters of dentition, each rat was identi- Milne-Edwards 1871 in some literature), is widely distrib- fied, and some inconclusive specimens were confirmed uted in Asian countries (Guo et al. 2000; Tobin and Fall by postmortem examination of skull (Huang et al. 1995; 2004; Wilson and Reeder 2005). This species is an agri- Guo 1999a, b). cultural pest that is abundant in Yunnan. Moreover, it is In the laboratory, the collected gamasid mites were an important infectious source and reservoir host of made into glass slide specimens before identification. plague, murine typhus (endemic typhus), scrub typhus Most small and soft mites were rinsed with clean water (tsutsugamushi disease), HFRS, and some other zoonoses to remove the ethanol and mounted on glass slides with (Singleton 2003; Singleton et al. 2004; Plyusnina et al. Hoyer’s medium (Pan and Deng 1980; Deng et al. 1993; 2009; Jonsson et al. 2010). The ectoparasites (including Guo 1997, 1999a, b). Some large and hard mites were ectoparasitic gamasid mites) on the rat are often associated mounted with abienic balsam after digestion, dehydration, with the preservation and transmission of plague, HFRS, and transparency processing (Pan and Deng 1980; Deng and some other zoonoses (He et al. 1997; Guo et al. et al. 1993; Luo et al. 2007). All the mounted mite 2000; Yin et al. 2011). Therefore, it is of importance to specimens were finally identified to species by microsco- study the ectoparasites (including ectoparasitic gamasid py (Pan and Deng 1980;Dengetal.1993). Voucher mites) found on the Asian house rat. Based on former mites and representative rats are deposited in the speci- investigations from Yunnan (Guo 1997, 1998,1999a, b; men repository of the Institute of Pathogens and Vectors, Guo and Qian 2001; Luo et al. 2007; Huang et al. 2010), Dali University, China. the current paper reports the species composition, species Some commonly used indices were calculated for each diversity, and dominant species of gamasid mites on R. mite species, including constituent ratio (Cr), infestation tanezumi in different types of habitat, and includes an prevalence (P), infestation mean abundance (MA), and in- analysis of the spatial distribution pattern and sex structure festation mean intensity (MI) (Margolis et al. 1982; of the dominant mite species. Whitaker 1988; Bush et al. 1997; Guo 1999a; Men et al. 2007). Shannon-Wiener’s diversity index (H) was used to calculate the community diversity of gamasid mite commu- Materials and methods nity (Diker et al. 2004; Magurran 1988;Krebs1985; Shannon and Weaner 1949;ZhaoandGuo1990). The Asian house rats were sampled from 1990 to 2008 in 28 parameter K from the negative binomial distribution locations (counties) across Yunnan Province. The 28 (Waters 1959) was used to determine the spatial distribution counties included were Gongshan, Weixi, Lanping, patterns of the dominant mite species. Xianggelila, Lijiang, Jianchuan, Heqing, Baoshan, Dali, Yangbi, Binchuan, Xiangyun, Weishan, Nanjian, Puer, Ninger, Yuanjiang, Yingjiang, Gengma, Menghai, Fuyuan, Results Qiaojia, Suijiang, Qiubei, Wenshan, Maguan, Mengzi, and Hekou. The rats were randomly trapped with mousetraps in A total of 19,304 gamasid mites collected from 4,113 two types of habitat: indoor habitats (including farmers’ Asian house rats, R. tanezumi, were identified as compris- houses, barns, and stables) and outdoor habitats (including ing 50 species. The majority of rats harbored the mites farmlands, scrublands, and woodlands). The mousetraps with a total infestation rate (P) of 97.84 %, MA of 4.69 were set in the evening and then checked the following mites per examined rat and MI of 4.80 mites per infested morning. Each trapped rat was placed in a pre-marked rat. Of 50 mite species, 31 species were ectoparasites white cloth bag and transferred to the laboratory where it while 19 species were free-living mites (Table 1). The was anesthetized and systematically examined. Gamasid Cr of three dominant mite species reached 91.8 % of mites on the body surface of each rat host, together with the total, and these dominant mites were Laelaps nuttalli those scattered on the white cloth bag, were comprehen- Hirst 1915, Laelaps echidninus Berlese 1887, and sively collected over a large white tray with the help of a Ornithonyssus bacoti Hirst 1913. The P, MA, and MI of magnifier. Mites from each host were preserved in vials of the eight main species were much higher than those of the 70 % ethanol (Pan and Deng 1980;Dengetal.1993; remaining 42 mite species, values of which were so low Durden et al. 1997, 2004). After collection, the white plate they are not presented (Table 2). Author's personal copy Parasitol Res (2013) 112:1967–1972 1969 Table 1 Gamasid mites and their living types collected from Asian house rats, Rattus tanezumi in Yunnan, Southwest China Living types Collected gamasid mites from Asian house rats Number Species names and collected individuals of the mites of species Ectoparasites 31 Laelaps nuttalli (10,938); L.