Ectoparasites of the Swift Fox in Northwestern Texas

Abstract

Ectoparasites were collected from chemically immobilized swift foxes (Vulpes velox) in the Texas Panhandle (USA). Three species of fleas (Pulex irritans, Dactylopsylla percernis, and Euhoplopsyllus affinis) and one species of tick (Ixodes sculptus) were found. Pulex irritans was the only abundant ectoparasite; it occurred on all 23 foxes brushed in 1999-2000 and all but one of 34 hosts examined in 2000-01. Otherwise, this swift fox population had a depauperate ectoparasite fauna; the remainder of the ectoparasites only occurred on a few (< or =5%) of the hosts. Because of previous taxonomic confusion between P. irritans and the closely related P. simulans, the zoogeographic distribution of these two species in many areas of western North America needs to be verified. Apparently, only the human flea P. irritans occurs on wild canids in the Texas Panhandle. However, there are previous records of P. simulans on other carnivores in western and central Texas. Some of these specimens were reexamined, and their identifications were reconfirmed. Also, the recent literature on the controversial taxonomic status of these two flea species is reviewed. The male terminal aedeagal sexual apparatus is the only means currently available to separate P. irritans and P. simulans.

Possible Vector Dissemination by Swift Foxes following a Plague Epizootic in Black-tailed Prairie Dogs in Northwestern Texas

“…The swift fox study site is on a 100-km 2 area that includes parts of the RBNG and private lands in Dallam County (36.2uN, 102.4uW). Pence et al (2004) described the study site and documented the swift fox ectoparasite fauna during an interepizootic period (1999)(2000)(2001) for plague in the endemic prairie dog colonies.…”

“…During June 2004, 12 swift foxes were captured and handled using methods described by Kamler et al (2002). Ectoparasites were collected according to the methods of Pence et al (2004) and placed in labeled vials that contained saline solution. Collected samples were stored at 4 C and transported to the CDC for Y. pestis testing and flea species identification as previously described.…”

“…Fleas were preserved in vials of 70% ethanol. These specimens were transported to Texas Tech University Health Sciences Center (Lubbock, Texas), where they were processed and identified according to the methods outlined in Pence et al (2004). Males of the genus Pulex were identified as either P. irritans or P. simulans using reference specimens (R. E. Lewis, Ames, Iowa, USA).…”

“…Pulex irritans is the most prevalent and abundant ectoparasite on swift foxes (Kilgore, 1969;Miller et al, 1998;Pybus and Williams, 2003;Pence et al, 2004). Kilgore (1969) collected 76 male P. irritans, five male P. simulans, and 133 females identified only as Pulex spp.…”

Deltamethrin flea-control preserves genetic variability of black-tailed prairie dogs during a plague outbreak

“…For example, BTPDs are the main food source for the federally endangered black-footed ferret Mustela nigripes; mountain plovers Charadrius montanus select BTPD colonies over other grasslands for nesting (Dreitz et al 2006;Dinsmore and Smith 2010); and swift fox Vulpes velox locate their dens on prairie habitats close to BTPD colonies (Pence et al 2004). Because plague can cause &99% mortality of BTPDs during epizootics and induces chronic (low level) mortality in BTPD populations during inter-epizootic periods , the important roles BTPDs play in prairie ecosystems are compromised by this disease (Biggins and Kosoy 2001;Cully and Williams 2001;Antolin et al 2002).…”