Parasites of the Black-Tailed Prairie Dog (Cynomys ludovicianus) from Eastern New Mexico

Fifty black-tailed prairie dogs from three prairie dog towns in eastern New Mexico harbored one nematode (Subulura sp.) and one acanthocephalan (Moniliformis clarki) species. One tick (Ornithodoros turicata) and one mite (Proctolaelaps sp.) species were recovered, whereas three species of fleas (Opisocrostis hirsutus, Pulex simulans, Echidnophaga gallinaced) were present. All represent new distribution records, and Subulura sp., O. turicata, Proctolaelaps sp., and E. gallinacea represent new host records. Male hosts had higher mean flea and nematode intensities. Male and female hosts in the lightest weight class had greater abundance of fleas. Greater flea intensities may be associated with reproductive cycles of host. There are few studies on parasites of the blacktailed prairie dog in North America (Buscher and Tyler, 1975; Tyler and Buscher, 1975; McKenna et al., 1977). Noteworthy is that there are few helminth species reported from this host (Vetterling, 1962). Trematodes have not been reported. Only five cestode species are reported (Buscher and Tyler, 1975, Raillietina sp. and Raillietina salmoni; Vetterling, 1962, Cladotaenia circi, Cladotaenia globifera, and Hymenolepis sp.). Moniliformis clarki, the only acanthocephalan reported from this host, was recovered in South Dakota prairie dogs (Vetterling, 1962). Adults (Trichostrongylus texanus, Rodenberg and Pence, 1978; Physaloptera getula, Hepaticola hepatica, and Spiroptera sp., Vetterling, 1962) and eggs (Physaloptera massino, Vetterling, 1962) of five nematode species have been reported from this host. Normally their prevalence is very low (Vetterling, 1962; Buscher and Tyler, 1975; McKenna et al., 1977), which contrasts sharply with the findings of Rodenberg and Pence (1978). They observed a 60% (9/15) prevalence in prairie dogs from Texas. Ectoparasites reported from this host include mites (Euschoengastoides hoplai, Loomis, 1971), ticks (Ixodes sp., McKenna et al., 1977), sucking lice (Neohaematopinus marmotae, Spencer, 1966; Hoplopleura acanthopus, McKenna et al., 1977) and fleas. Fleas from this host include Pulex simulans (Smit, 1958; Hubbard, 1968), Opisocrostis hirsutus (Hubbard, 1968; Tyler and Buscher, 1975; McKenna et al., 1977), Opisocrostis bruneri, Opisocrostis tuberculatus cynomuris, and Thrassis fotus (McKenna et al., 1977). The present study was initiated to (1) supplement existing information about parasite distributions, (2) compare our results with other published information, and (3) determine if parasite distributions and intensities differ among three prairie dog towns located near Portales, New Mexico. Materials and Methods Fifty prairie dogs were collected from three prairie dog towns near Portales, Roosevelt County, New Mexico, in May-June and September-November 1981. The towns were identified as preserve (P), Crow's (C), and dairy (D). Town P is located approximately 10 mi NE of the other two towns. It is characterized as a shortgrass prairie dominated by blue grama (Bouteloua gracilis), side-oats grama (Bouteloua curtipendula), purple three-awn (Aristida purpurea), and sand dropseed (Sporobolus cryptandrus) with the predominant shrub being sand sage (Artemisia fitifolid). Town C was being grazed by cattle but not extensively and is dominated by blue grama and side-oats grama grasses with the dominant shrub being honey mesquite (Prosopis glandulosa). Town D is a nearly barren, caliche flat characterized by a low (2"-4"), sparse stand of kochia weed (Kochia scoparia) and is also grazed by cattle. Animals were trapped using 4-inch steel jaw traps that were checked twice daily at 7 A.M. and 7 P.M. Prairie dogs were removed from the traps using a grasping snake stick and immediately placed in large, heavy gauge plastic bags containing cotton soaked in chloroform. Death occurred by thoracic compression. Each bag containing a single carcass was immediately tied, labeled, and placed in a freezer within 2 hr of capture. Frozen carcasses were later weighed, sexed, and skinned. The feet, tail, and linings of ears and nostrils were also removed along with the hide and placed in a jar of 25% KOH solution and allowed to dissolve at room temperature. In approximately 18-24 hr the solution was strained through a series (850-, 600-, 420-, 300-, 212-, and 149-Mm openings) of sieve screens. Recovered ectoparasites were stored in 70% ethyl alcohol. Fleas were transferred from 70% ethanol to 100% ethanol and cedarwood oil and mounted in euparal.