Ralph P. Eckerlin

Beringia: Intercontinental exchange and diversification of high latitude mammals and their parasites during the Pliocene and Quaternary

ABSTRACT Beringia is the region spanning eastern Asia and northwestern North America that remained ice-free during the full glacial events of the Pleistocene. Numerous questions persist regarding the importance of this region in the evolution of northern faunas. Beringia has been implicated as both a high latitude refugium and as the crossroads (Bering Land Bridge) of the northern continents for boreal mammals. The Beringian Coevolution Project (BCP) is an international collaboration that has provided material to assess the pattern and timing of faunal exchange across the crossroads of the northern continents and the potential impact of past climatic events on differentiation. Mammals and associated parasite specimens have been collected and preserved from more than 200 field sites in eastern Russia, Alaska and northwestern Canada since 1999. Previously, fossils and taxonomic comparisons between Asia and North America mammals have shed light on these events. Molecular phylogenetics based on BCP specimens is now being used to trace the history of faunal exchange and diversification. We have found substantial phylogeographic structure in the Arctic and in Beringia in mustelid carnivores, arvicoline rodents, arctic hares and soricine shrews, including spatially concordant clades and contact zones across taxa that correspond to the edges of Beringia. Among the tapeworms of these mammalian hosts, new perspectives on diversity have also been developed. Arostrilepis horrida (Hymenolepididae) was considered to represent a single widespread and morphologically variable species occurring in a diversity of voles and lemmings in eastern and western Beringia and more broadly across the Holarctic region. The BCP has demonstrated a complex of at least 10 species that are poorly differentiated morphologically. The diversity of Paranoplocephala spp. and Anolocephaloides spp. (Anoplocephalidae) in Beringia included relatively few widespread and morphologically variable species in arvicolines. BCP collections have changed this perspective, allowing the recognition of a series of highly endemic species of Paranoplocephala that demonstrate very narrow host specificity, and additional species complexes among arvicolines. Thus, extensive, previously unrecognized, diversity for tapeworms of 2 major families characterizes the Beringian fauna. By elucidating evolutionary relationships and phylogeographic variation among populations, species and assemblages, refined views of the sequence and timing of biotic expansion, geographic colonization and impact of episodic climate change have been developed for Beringia. Ultimately, Beringia was a determining factor in the structure and biogeography of terrestrial faunas across the Nearctic and Neotropical regions during the Pliocene and Quaternary.

Effects of Land Use on Plague (Yersinia pestis) Activity in Rodents in Tanzania

Understanding the effects of land-use change on zoonotic disease risk is a pressing global health concern. Here, we compare prevalence of Yersinia pestis, the etiologic agent of plague, in rodents across two land-use types-agricultural and conserved-in northern Tanzania. Estimated abundance of seropositive rodents nearly doubled in agricultural sites compared with conserved sites. This relationship between land-use type and abundance of seropositive rodents is likely mediated by changes in rodent and flea community composition, particularly via an increase in the abundance of the commensal species, Mastomys natalensis, in agricultural habitats. There was mixed support for rodent species diversity negatively impacting Y. pestis seroprevalence. Together, these results suggest that land-use change could affect the risk of local transmission of plague, and raise critical questions about transmission dynamics at the interface of conserved and agricultural habitats. These findings emphasize the importance of understanding disease ecology in the context of rapidly proceeding landscape change.

Drivers of Intensity and Prevalence of Flea Parasitism on Small Mammals in East African Savanna Ecosystems

Abstract:  The relative importance of environmental factors and host factors in explaining variation in prevalence and intensity of flea parasitism in small mammal communities is poorly established. We examined these relationships in an East African savanna landscape, considering multiple host levels: across individuals within a local population, across populations within species, and across species within a landscape. We sampled fleas from 2,672 small mammals of 27 species. This included a total of 8,283 fleas, with 5 genera and 12 species identified. Across individual hosts within a site, both rodent body mass and season affected total intensity of flea infestation, although the explanatory power of these factors was generally modest (<10%). Across host populations in the landscape, we found consistently positive effects of host density and negative effects of vegetation cover on the intensity of flea infestation. Other factors explored (host diversity, annual rainfall, anthropogenic disturbance, and soil properties) tended to have lower and less consistent explanatory power. Across host species in the landscape, we found that host body mass was strongly positively correlated with both prevalence and intensity of flea parasitism, while average robustness of a host species to disturbance was not correlated with flea parasitism. Cumulatively, these results provide insight into the intricate roles of both host and environmental factors in explaining complex patterns of flea parasitism across landscape mosaics.

The Flea (Siphonaptera) Fauna of Georgia, U.S.A: Hosts, Distribution and Medical-Veterinary Importance

ABSTRACT Host and distribution data are provided for the 26 species of fleas recorded from Georgia, U.S.A.: Cediopsylla inaequalis, C. simplex (rabbit flea), Ctenocephalides canis (dog flea), C. felis (cat flea), Echidnophaga gallinacea (sticktight flea), Pulex irritans (human flea), P. simulans, Xenopsylla cheopis (Oriental rat flea), Polygenis gwyni, Conorhinopsylla stanfordi, Ctenophthalmus pseuadagyrtes, Doratopsylla blarinae, Epitedia cavernicola, E. wenmanni, Nearctopsylla georgiana, Stenoponia americana, Ceratophyllus celsus, Nosopsyilus fasciatus (northern rat flea), Orchopeas howardi (squirrel flea), O. leucopus, O. pennsylvanicus, Leptopsylla segnis (European mouse flea), Odontopsyllus multispinosus, Peromyscopsylla hesperomys, P. scotti and Sternopsylla distincta texana. Three of these species, P. gwyni, N. georgiana and O. howardi, were described from Georgia specimens. While some of these flea species appear to be widely distributed throughout Georgia, C. inaequalis represents an introduction on hosts introduced for hunting from western North America, D. blarinae, E. cavernicola, N. georgiana, C. celsus and P. hesperomys were recorded only from Piedmont or mountainous regions in northern Georgia, and P. gwyni was mainly recorded in the Coastal Plain of southern Georgia. Nearctopsylla georgiana is known from only a single specimen and has never been recorded outside of northern Georgia. Fleas associated with domestic rats (Rattus norvegicus and R. rattus) were abundant in Georgia, especially coastal and southern Georgia during the 1930s–1950s but currently appear to be uncommon in the state. There were concerted control efforts against Rattus spp. and their fleas during that time period because of their reservoir and vector status, respectively, for Rickettsia typhi, the causative agent of murine (endemic) typhus. Human cases of murine typhus in Georgia have almost disappeared in recent decades. Other flea-borne diseases in Georgia include cat flea rickettsiosis caused by Rickettsia felis, bartonellosis (including cat scratch disease caused by Bartonella henselae), and sylvatic epidemic typhus caused by certain strains of Rickettsia prowazekii. Further, cat and dog fleas are intermediate hosts of the double-pored tapeworm, Dipylidium caninum, which typically infects dogs but can also infect cats and humans if infected fleas are inadvertently ingested. Human and pet-biting fleas such as the cat flea can also cause flea-bite dermatitis in dogs, cats and humans. Poultry fleas such as E. gallinacea currently appear to be uncommon on domesticated birds in Georgia but this flea sometimes infests chickens, dogs and some other mammals in fairly large numbers.

Host–Parasite Associations in Small Mammal Communities in Semiarid Savanna Ecosystems of East Africa

Abstract Despite the established importance of rodents as reservoirs of vector-borne zoonoses in East Africa, there is relatively limited information regarding the infestation parameters and host associations of ectoparasites that vector many such pathogens among small mammals in this region. Between 2009 and 2013, small mammals were live-trapped in the semiarid savanna of Kenya. A subset of these individual hosts, including 20 distinct host taxa, was examined for ectoparasites, which were identified to species. Species of fleas, ticks, mites, and sucking lice were recorded. Based on these data, we calculated host-specific infestation parameters, documented host preferences among ectoparasites, conducted a rarefaction analysis and extrapolation to determine if ectoparasites were adequately sampled, and assessed nestedness for fleas to understand how pathogens might spread in this system. We found that the flea community structure was significantly nested. Understanding the ectoparasite network structure may have significant human relevance, as at least seven of the ectoparasite species collected are known vectors of pathogens of medical importance in the region, including Yersinia pestis, Rickettsia spp., and Theileria parva, the causative agents of plague, spotted fevers and other rickettsial illnesses in humans, and theileriosis, respectively.

Description of the male and redescription of the female of Ixodes (Ixodes) guatemalensis and description of the male, nymph and larva of Ixodes (Afrixodes) moreli and redescription of the female (Acari: Ixodida: Ixodidae)

Abstract Original descriptions are provided for the male of Ixodes (Ixodes) guatemalensis Kohls and the male, nymph and larva of Ixodes (Afrixodes) moreli Arthur from material collected in Guatemala and Equatorial Guinea, respectively. Because of the rarity of these two species and for the sake of completeness, redescriptions of the females are also provided.

A New Anoplocephalid Cestode from the Southern Bog Lemming Synaptomys cooperi

Abstract A new cestode species, Anoplocephaloides bulmeri n. sp. (Cestoda: Anoplocephalidae), is described from the southern bog lemming Synaptomys cooperi (Baird) from Virginia. The general morphology of A. bulmeri strongly suggests that it belongs to the monophyletic Anoplocephaloides Baer 1923 s. str. It differs unequivocally from the other species of Anoplocephaloides s. str. by the distribution of testes in the poral part of the proglottid and also by the number of testes and the maximum length of the cirrus sac and seminal receptacle. Anoplocephaloides bulmeri most closely resembles Anoplocephaloides kontrimavichusi Rausch, 1976, a host-specific parasite of the northern bog lemming, Synaptomys borealis (Richardson).

COYOTES (CANIS LATRANS) IN GUATEMALA

Abstract Records of coyotes (Canis latrans) from Guatemala are based mostly on observational records. We review existing literature for coyotes in Guatemala and report the first specimen from this country.

The Fleas (Siphonaptera) of West Virginia

ABSTRACT Thirty-five species of fleas are documented from the state of West Virginia including new state records for the ischnopsyllid, Nycteridopsylla chapini Jordan, 1929, and the ctenophthalmid, Corrodopsylla curvata (Rothschild, 1915). Host and distribution records are presented by county, with many new records, including 88 new county records amassed since 1980. The most widely distributed fleas were Orchopeas leucopus (Baker, 1904) and Peromyscopsylla hesperomys hesperomys (Baker, 1904), both from mice of the genus Peromyscus. Ctenophthalmus pseudagyrtes (Baker, 1904) was abundant on shrews, voles, and mice. The squirrel flea, Orchopeas howardi (Baker, 1895), found in 12 counties from west to east in the state is probably present throughout the state. This species has been implicated in the maintenance and spread of sporadic epidemic typhus. The cat flea, Ctenocephalides felis (Bouché, 1835), a parasite primarily of domestic cats and dogs, was not well represented in our collections, but is widespread geographically and probably occurs throughout the state. This is the most economically important species in West Virginia as a household pest and carrier of several zoonotic human pathogens.

Small mammals from the Chelemhá Cloud Forest Reserve, Alta Verapaz, Guatemala

Abstract We surveyed the small mammals of remnant mixed hardwood-coniferous cloud forest at elevations ranging from 2,100–2,300 m in the Chelemhá Cloud Forest Reserve, Alta Verapaz, Guatemala. Removal-trapping using a combination of live traps, snap traps, and pitfall traps for 6 days in January 2007 resulted in 175 captures of 15 species of marsupials, shrews, and rodents. This diversity of small mammals is the highest that we have recorded from a single locality of the 10 visited during eight field seasons in the highlands of Guatemala. Based on captures, the most abundant species in the community of small mammals is Peromyscus grandis (n = 50), followed by Handleyomys rhabdops (n = 27), Heteromys desmarestianus (n = 18), Reithrodontomys mexicanus (n = 17), Handleyomys saturatior (n = 16), Sorex veraepacis (n = 15), and Scotinomys teguina (n = 13). The remaining eight species were represented by one to five individuals.