Food and Ectoparasites of Shrews 101 



on five species of fleas, four species of laelapid mites, one species 

 of acarid mite, and a species of Pygmephorus. 



DISCUSSION 



Both B. carolinensis and B. brevicauda eat a wide variety of 

 foods: 23 categories of food items in the South Carolina material 

 (n = 45), compared with 36 categories in the much larger sample of 

 B. brevicauda (n = 125) from Indiana. The lower percent volume of 

 earthworms observed for B. carolinensis likely represents the low numbers 

 of earthworms that are supported by the sandy soils of the Savannah 

 River Site, rather than a difference in dietary preference between 

 B. carolinensis and B. brevicauda. 



The hypogeous mycorrhizal fungus Endogone was one of the 

 more heavily eaten foods in the shrews from South Carolina at 16.3% 

 of the volume, but formed only 3.6% of the total volume in the foods 

 of Indiana shrews. Endogone (including related genera, see Castellano 

 et al. 1989) often is important as a food of small mammals (Whitaker 

 1962, Williams and Finney 1964). The small mammal-fungal relationship 

 is an important component of many communities because small 

 mammals act as dispersal agents for mycorrhizal fungi (Maser et al. 

 1978). 



Of the five ectoparasitic species that previously had been 

 reported from B. carolinensis, all were found during our study (marked 

 with asterisks, Table 2) except for Haemogamasus harperi. The flea 

 most frequently observed on B. brevicauda, Ctenopthalmus pseudagyrtes, 

 was not collected from B. carolinensis; however, C. pseudagyrtes does 

 occur on the Savannah River Site, and has been observed on eastern 

 moles, Scalopus aquaticus (G. D. Hartman, unpublished data). The 

 most abundant mites on Blarina tend to be the tiny Asiochirus Marina 

 (Listrophoridae) and hypopi of Orycteroxenus soricis (Acaridae); both 

 of these ectroparasites likely were more abundant than the data indicate. 



The number of ectoparasite species observed on B. carolinensis 

 was less than for B. brevicauda, in part because of the smaller number 

 of B. carolinensis examined. However, in spite of the different sample 

 sizes, there were notable differences between the ectoparasite assemblages. 

 Of 27 species observed on B. carolinensis, 14 were found only on this 

 host, and of the 32 species reported for B. brevicauda, 19 were found 

 only on that host. Anoetids, cyrtolaelapids, trombiculids, and the genus 

 Bakerdania (Pygmephoridae) were observed only on B. carolinensis. 

 Although the species of Pgymephorus found on the two host species 

 were not similar, this is not too surprising because pygmephorid 

 mites that occur on mammals are not host specific. 



