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DISCUSSION
The current study aimed to assess the ectoparasite community harboured by Micaelamys namaquensis and identify the most important species. In addition, we investigated the impact of abiotic and biotic factors on ectoparasite distribution in the study species. Our study is the first long-term assessment of ectoparasite burdens of M. namaquensis from a single locality and provides novel data on the ectoparasite species found on the rock mouse in South Africa. We recorded a great diversity of ectoparasites, which consisted of 23 species from four taxa. A previous review by De Graaff (1981) lists an impressive numbers of ectoparasite species collected from M. namaquensis in the southern African sub-region including 34 species of fleas, two families of mites namely Laelaptidae and Trombiculidae, 13 species of tick species and no louse species. The present study found five species of fleas, six species and one family (Trombiculidae) of mites, as well as eight species of ticks. In comparison to De Graaff (1981) records, this diversity appears low. However, it is worth stressing that De Graaff’s records were accumulated across the entire geographical distribution of the study species. Hence the number of ectoparasite species recorded in the present study is remarkably large since it stems from a single locality. The present study makes a valuable contribution in regards of reporting a new host as well as new locality records of three species of lice (H. patersoni, H. aethomydis and P. praomydis) and two species of mites (A. rhabdomysi and L. roubaudi).
The results of the current study show that fleas and ticks were the most prevalent ectoparasite taxa infesting M. namaquensis followed by mites. Five flea species were recorded of which Xenopsylla brasiliensis (Siphonaptera: Pulicidae), Chiastopsylla godfreyi (Siphonaptera: Chimaeropsyllidae) and Epirimia aganippes (Siphonaptera: Chimaeropsyllidae) were the most prevalent. Although these three flea species were the most prevalent they only occur at low abundances. Most of the species of flea collected occur throughout South Africa (Segerman 1995). Praomys natalensis (Rodentia: Muridae), Aethomys chrysophilus (Rodentia: Muridae) and M. namaquensis (Rodentia: Muridae) are the main natural hosts of X. brasiliensis (Segerman 1995), which suggests that X. brasiliensis has a low host specificity, while Chiastopsylla godfreyi and Epirimia aganippes are reported to be host-specific for M. namaquensis (Segerman 1995; Braack et al. 1996; Mfune et al. 2013). In addition, two species of flea were also reported in the present study, namely Demeillonia granti (Siphonaptera: Chimaeropsyllidae) and Dinopsyllus ellobius (Siphonaptera: Hystrichopsyllidae). Both species occurred at low prevalence and abundance. This may be explained by the fact that D. granti is hostspecific for sengis, while D. ellobius prefers hosts such as gerbils (Tatera spp., Rodentia: Muridae), multimammate mice (P. natalensis) and four striped mice (Rhabdomys pumilio, Rodentia: Muridae , Fourie et al. 1995; Segerman 1995). Little is known about the louse species collected in the present study. Of the three louse species recorded Hoplopleura spp. were the most prevalent, but both species occurred at low abundance. The low louse abundance may be attributed to low host density in the study area, high temperatures and low humidity affecting the survival of lice (Cooke 1984; Cooke and Skewes 1988). In addition, lice are highly host specific and it is known for some louse species to infest two or more closely related host species (Durden and Musser 1994). All louse species collected in the present study have been previously reported for M. namaquensis and the closely related red veld rat (Aethomys chrysophilus, Ledger 1980; Braack et al. 1996), which suggests that these louse species may be specific for the genera Aethomys and Micaelamys. A total of seven mite species were collected. By far the most prevalent and abundant mites recorded in the current study were Trombiculid larvae (chiggers). The identity of the chigger larvae collected in the present study is uncertain mainly because of lack of taxonomic expertise in South Africa. Trombiculid mites are a diverse group in the Acari and only the larval stages are parasitic on a wide range of small mammals and birds (Ewing 1944). Chiggers are known for their low host specificity and have been reported by other researchers, e.g. van der Mescht (2011) found high infestations of trombiculid larvae on R. pumilio in the Western Cape Province, South Africa. Matthee et al (2007) also reported chigger mites on R. pumilio. The second common species of mite (A. rhabdomysi) has been previously collected from R. pumilio in the Western Cape (Matthee et al. 2007; Matthee and Ueckermann 2008; van der Mescht 2011). The remaining mite species occurred at low abundance and have been reported before for a number of other rodent species (Zumpt 1961).
Several species of ticks have been collected in the present study, with exception of R. distinctus and Haemaphysalis spp. all these occurred at low prevalence and abundance.
This is possibly due to the host preference of most of these ticks. With the exception of R. warburtoni and R. arnoldi most of the Rhipicephalus spp. collected are known to prefer hosts living in grassland habitats rather than rocky outcrops. Eastern rock sengis are also known to be the preferred host for R. warburtoni, R. arnoldi and Ixodes (Horak et al. 2005; Harrison et al. 2011, 2012; Fagir et al. 2015).
Study area and capture plots
Eastern rock sengis were sampled at Telperion/Ezemvelo Nature Reserve (25° 41’ S, 28° 56’ E) located on the border between Gauteng and Mpumalanga Provinces, South Africa. The reserve is approximately 11000 ha in size and the vegetation cover is described as highveld grassland and savannah with large rocky outcrops that occur throughout the reserve (Swanepoel 2006). Sampling took place five times from April 2010 until May 2011 to cover all seasons (April/May 2010, July/August 2010, October/November 2010; January/February 2011, April/May 2011). Sixteen plots comprising eight rocky outcrops and eight grasslands were selected for the study. However, this procedure was changed during the first trip (April 2010) where sampling took place from only five rocky outcrops and one grassland plot. In addition, during the last trip (April 2011) sengis were only sampled from rocky outcrops (8 plots).
Host species and trapping protocol
Animals were collected using 72 Live-Sherman traps (H. B. Sherman Traps, Inc., Tallahassee, Florida) baited with a mixture of peanut butter and oats to attract animals.
Traps were set in each plot in four parallel straight lines approximately 10 m apart and each line consisted of 18 traps with10 m between traps. Traps were set overnight for four consecutive nights. They were opened in the late afternoon (around 18:00), checked early each morning (around 05:00) and kept closed during the day. To limit trap related deaths as a result of environmental exposure, bedding was provided in the traps during winter.
CHAPTER 1
GENERAL INTRODUCTION
-REFERENCES
CHAPTER 2
ECTOPARASITE SPECIES ASSOCIATED WITH THE NAMAQUA ROCK MOUSE (MICAELAMYS NAMAQUENSIS) IN SOUTH AFRICA
-SUMMARY
-INTRODUCTION
-MATERIALS AND METHODS
-RESULTS
-DISCUSSION
-REFERENCES
CHAPTER 3
ECTOPARASITE BURDENS IN THE EASTERN ROCK SENGI (ELEPHANTULUS MYURUS): THE EFFECT OF SEASONALITY AND HOST SEX
-SUMMARY
-INTRODUCTION
-MATERIALS AND METHODS
-RESULTS
-DISCUSSION
-REFERENCES
CHAPTER 4
THE LONG TERM DYNAMIC OF THE ECTOPARASITE COMMUNITY OF THE EASTERN ROCK SENGI (Elephantulus myurus) AND THE EFFECT OF PARASITISM ON HOST BODY CONDITION
-SUMMARY
-INTRODUCTION
-MATERIALS AND METHODS
-RESULTS
-DISCUSSION
-REFERENCES
CHAPTER 5
GENERAL DISCUSSION AND CONCLUSIONS
-REFERENCES
