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Ectoparasite and epifaunistic arthropod biodiversity and infestation parameters were compared between 2 sympatric small rodent species, the cotton mouse (Peromyscus gossypinus (Le Conte)) and golden mouse (Ochrotomys nuttalli (Harlan)), in southern Georgia from 1992 to 2003. Because the cotton mouse is known to be a reservoir of more vector-borne zoonotic pathogens than the golden mouse, we hypothesized that it would be parasitized by more ectoparasites that are known to be vectors of these pathogens. Cotton mice (n = 202) were parasitized by 19 species of arthropods, whereas golden mice (n = 46) were parasitized by 12 species. Eleven species of arthropods were recovered from both host species, whereas 7 were recorded only from cotton mice, and 1 species only from golden mice. Infestation prevalences (percent of mice parasitized) were significantly higher for 1 species of arthropod (the tropical rat mite Ornithonyssus bacoti (Hirst)) infesting cotton mice and for 4 species (the flea Peromyscopsylla scotti Fox and the mites Glycyphagus hypudaei Koch, Androlaelaps casalis (Berlese), and Androlaelaps fahrenholzi (Berlese)) infesting golden mice. Mean intensities (mean per infested mouse) were significantly higher for 2 species (the flea Orchopeas leucopus (Baker) and the blacklegged tick Ixodes scapularis Say) infesting cotton mice and for 2 species (G. hypudaei and A. fahrenholzi) infesting golden mice. Ectoparasites that are known to be vectors of zoonotic pathogens were significantly more common on cotton mice than on golden mice. These ectoparasites included the rhopalopsyllid flea Polygenis gwyni (Fox), a vector of the agent of murine typhus; I. scapularis, the principal vector of the agents of Lyme borreliosis, human granulocytic ehrlichiosis, and human babesiosis; and O. bacoti, a laboratory vector of several zoonotic pathogens. However, 2 species of ixodid ticks that can transmit zoonotic pathogens were recovered from both host species. These were the American dog tick Dermacentor variabilis (Say), the principal vector of the agent of Rocky Mountain spotted fever in eastern North America, and Ixodes minor Neumann, an enzootic vector of the agent of Lyme borreliosis. Overall, the cotton mouse was parasitized by significantly more ectoparasites that are known to be vectors of zoonotic pathogens than was the golden mouse. These data support the hypothesis that the cotton mouse has greater epidemiological importance for zoonotic vector-borne pathogen transmission than does the golden mouse.

Ticks (Acari: Ixodidae) were collected from family-owned domestic dogs, Canis familiaris L., in Bulloch Co., GA, from 1996 to 2003 and from dogs maintained in a shelter in Emanuel Co., GA, in 2002 and 2003. A total of 2,466 ticks representing 9 species was recovered. The most frequently recovered species from family-owned dogs were the blacklegged tick, Ixodes scapularis Say (54.6% of all ticks from this group of dogs), and American dog tick, Dermacentor variabilis (Say) (27.7%). Collections from shelter-maintained dogs were dominated by the brown dog tick, Rhipicephalus sanguineus (Latreille) (73.6%). Except for 39 nymphs of the lone star tick, Amblyomma americanum (L.), 12 nymphs of R. sanguineus, 7 nymphs of the Gulf Coast tick, Amblyomma maculatum Koch, 1 nymph of D. variabilis and 72 larvae of the gopher tortoise tick, Amblyomma tuberculatum Marx, only adult ticks were present. Seasonally, I. scapularis adults were recorded from October through May and were most common in the fall; whereas, A. americanum, A. maculatum, A. tuberculatum, D. variabilis, and Ixodes affinis Neumann were all found only during the spring, summer and/or early fall. Two species of ticks collected during this study, A. tuberculatum and I. affinis, have Coastal Plain distributions in the southern U.S. and would only be expected to parasitize dogs within this region.

Eight complete cDNAs encoding for ferritins from the hard tick species Amblyomma americanum (L.), Amblyomma maculatum Koch, Boophilus microplus (Canestrini), Dermacentor albipictus (Packard), Dermacentor variabilis (Say), Hemaphysalis longicornis Neumann, Ixodes scapularis Say, and Rhipicephalus sanguineus (Latreille) were obtained using the techniques of rapid amplification of cDNA ends. The deduced amino acid sequences from these tick ferritin genes share high identities (84–98%) with those of two published tick ferritins. The sequences and positions of the iron-responsive element in the 5′-untranslated region of the cDNAs are highly conserved in ticks. Similar to other known animal ferritins, a ferroxidase center, consisting of seven conserved amino acid residues, was identified in the deduced tick ferritins. Sequence comparison indicates that these tick ferritin genes belong to the type of invertebrate cytosolic heavy chain homologue. Two separate phylogenetic analyses of ferritin amino acid sequences, one with 52 arthropod ferritin sequences and another one using 10 tick ferritins, suggested that ferritin is a suitable nuclear protein-encoding gene for tick phylogenetic reconstruction.

The Lyme disease spirochete, Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwalt, and Brenner, was discovered in blacklegged ticks, Ixodes scapularis Say at Turkey Point, Ontario, Canada. We report the first isolation of B. burgdorferi from a vertebrate animal collected on mainland Ontario. During this 2-yr study, spirochetes were isolated from the white-footed mouse, Peromyscus leucopus Rafinesque, and attached I. scapularis larvae. Similarly, isolates of B. burgdorferi were cultured from blacklegged tick adults, and confirmed positive with polymerase chain reaction by targeting OspA and rrf (5S)-rrl (23S) genes. Moreover, all isolates of B. burgdorferi from this area had complementary genetic structure, and the second primer set amplicons confirmed the first primer set amplification products. These findings show an epicenter endemic for B. burgdorferi within an established population of I. scapularis at Turkey Point.

Two putative cDNAs of acetylcholinesterase (AChE), one from Dermacentor variabilis, and the other from Rhipicephalus sanguineus, were amplified and sequenced. The deduced amino acid sequences have high amino acid identities (between 70 and 94%) to known tick AChE sequences deposited in GenBank. Furthermore, these two AChEs also possess common features in their primary AChE structure such as catalytic active sites. A 2,220-bp contiguous sequence, containing a 1,791-bp open reading frame encoding an AChE precursor with 596 amino acid residues, was obtained from D. variabilis. The deduced proteins of R. sanguineus are different in size by 6 amino acids because of alternative splicing at the 5' end. A gene tree deduced from phylogenetic analysis indicates that there are at least three lineages of AChE in arthropods.

Aim To document ectoparasitic arthropods of terrestrial vertebrates inhabiting barrier islands and to offer preliminary interpretations. Location The coast of Georgia, USA, with most data presented for St Catherines, Sapelo, Jekyll, and Cumberland islands. Methods Ectoparasites were collected and identified from hundreds of live-trapped mammals, birds, and reptiles. Ticks and louse-flies were also collected by dragging or flagging a white cloth through vegetation. Some ectoparasites were recovered from host nests or roosting sites. Literature records and specimen records from the US National Tick Collection supplemented these data. Results Inventories of ectoparasite species recovered from vertebrates on each island are provided. Many new records and a small number of undescribed species are reported. Main conclusions Compared with most ectoparasite faunas associated with the same host species on the adjacent mainland, ectoparasite species diversity on the barrier islands is depauperate. Possible reasons for this phenomenon are discussed including ecological, geological, and vicariant factors. Tick faunas do not appear to be depauperate on the islands probably because immature stages attach to visiting or migrating birds. Some host-ectoparasite associations that we recorded are atypical for mainland faunas. This trend has also been recorded in some previous surveys of insular ectoparasites and may be related to vacant ectoparasite niches on some islands.

The Ixodes ricinus species complex is a group of ticks distributed in almost all geographic regions of the world. Lyme borreliosis spirochetes are primarily transmitted by tick species within this complex. It has been hypothesized that the Lyme vector ticks around the world are closely related and represent a monophyletic group. This implies that vector competence in ixodid ticks for Lyme agents might have evolved only once. To test this hypothesis, we used a molecular phylogenetic approach. Two fragments of mitochondrial 16S ribosomal deoxyribonucleic acid were sequenced from 11 species in the I. ricinus complex and from 16 other species of Ixodes. Phylogenetic analysis using Bayesian methodology indicated that the I. ricinus complex is not a monophyletic group unless 3 additional Ixodes species are included in it. The known major vectors of Lyme disease agents in different areas of the world are not sister taxa. This suggests that acquisition of the ability to transmit borreliosis agents in species of Ixodes may have multiple origins.

Intracellular endosymbionts, Wolbachia spp., have been reported in many different orders of insects and in nematodes but not previously in fleas. This is the first conclusive report of Wolbachia spp. within members of the Siphonaptera. Using nested polymerase chain reaction (PCR) targeting of the 16S ribosomal RNA gene, we screened for Wolbachia spp. in fleas collected from 3 counties in Georgia and 1 in New York. The prevalence of Wolbachia spp. detected varied among the 6 different species screened: 21% in the cat flea Ctenocephalides felis (n = 604), 7% in the dog flea C. canis (n = 28), 25% in Polygenus gwyni (n = 8), 80% in Orchopeas howardi (n = 15), 94% in Pulex simulans (n = 255), and 24% in the sticktight flea Echidnophaga gallinacea (n = 101). Wolbachia spp. infection in fleas was confirmed by sequencing positive PCR products, comparing sequenced 16S ribosomal DNA (rDNA) with Wolbachia spp. sequences in GenBank using BLAST search, and subjecting sequence data to phylogenetic analysis. For further confirmation, 16S rDNA-positive samples were reamplified using the wsp gene.

The Lyme disease spirochete, Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwalt, and Brenner was discovered in blacklegged ticks, Ixodes scapularis Say at Rondeau Provincial Park, Ontario, Canada. During this 2-yr study, spirochetes were found in B. burgdorferi-positive I. scapularis larvae attached to B. burgdorferi-infected white-footed mice, Peromyscus leucopus Rafinesque. Isolates of B. burgdorferi were cultured from blacklegged tick adults, and confirmed positive with polymerase chain reaction by targeting OspA and rrf (5S)-rrl (23S) genes. These findings show an endemic area for B. burgdorferi within an established population of I. scapularis at Rondeau Provincial Park.

Seven species of ectoparasite were collected from 32 striped skunks, Mephitis mephitis, in south-central Connecticut, U.S.A., from July through September 2001. The most frequently collected ectoparasite was the chewing louse Neotrichodectes mephitidis, which was the only host-specific ectoparasite collected. Immature stages (larvae and nymphs) of 2 species of ticks, Ixodes cookei and the blacklegged tick, Ixodes scapularis, also were commonly collected. The remaining 4 species of ectoparasite consisted of 2 species of flea, Oropsylla arctomys and the cat flea, Ctenocephalides felis, the American dog tick, Dermacentor variabilis, and a macronyssid mite, Ornithonyssus wernecki, that normally parasitizes the Virginia opossum. Overall, the ectoparasite fauna of the striped skunk appears to be relatively depauperate. However, D. variabilis, I. cookei, I. scapularis, and C. felis are known to be vectors of zoonotic pathogens.

Bacterial community composition in blood-sucking arthropods can shift dramatically across time and space. We used 16S rRNA gene amplification and pyrosequencing to investigate the relative impact of vertebrate host-related, arthropod-related and environmental factors on bacterial community composition in fleas and ticks collected from rodents in southern Indiana (USA). Bacterial community composition was largely affected by arthropod identity, but not by the rodent host or environmental conditions. Specifically, the arthropod group (fleas vs ticks) determined the community composition of bacteria, where bacterial communities of ticks were less diverse and more dependent on arthropod traits--especially tick species and life stage--than bacterial communities of fleas. Our data suggest that both arthropod life histories and the presence of arthropod-specific endosymbionts may mask the effects of the vertebrate host and its environment.

Twelve species (292 individuals) of small mammals were livetrapped and examined for parasitic arthropods in 17 localities in Mississippi from June through November 1998. Fifteen species of ectoparasites were collected: 2 species of sucking lice (Anoplura), 4 species of fleas (Siphonaptera), larvae of 2 species of bots (Cuterebridae), 4 species of mesostigmatid mites (Mesostigmata), and immature stages of 3 species of hard ticks (Ixodidae). The white-footed mouse (Peromyscus leucopus) harbored the most species of parasitic arthropods (8), followed by the cotton mouse (Peromyscus gossypinus—6), and the cotton rat (Sigmodon hispidus—5). New state records for Mississippi were established for the sucking louse Hoplopleura hirsuta, the bot Cuterebra americana, the laelapid mite Laelaps alaskensis, and the fleas Orchopeas pennsylvanicus and Peromyscopsylla scotti.

The male and female of Amblyomma geochelone n. sp. are described and illustrated by both scanning electron micrographs and line drawings. Specimens of this new tick species were recovered from the endangered ploughshare tortoise, Geochelone yniphora (Vaillant), in northwestern Madagascar. This relatively large tick is morphologically most similar to Amblyomma nuttalli Donitz, which occurs in mainland sub-Saharan Africa where it mainly parasitizes other species of tortoises. However, several characters distinguish the new species from A. nuttalli including the scutal ornamentation in both sexes and the characteristic patterns of shallow grooves on the alloscutum of the female of A. geochelone. Because the adult stages of A. geochelone are almost certainly host specific ectoparasites of the ploughshare tortoise, this new tick species is also probably endangered.

From 1982–1985 and 1993–1999, a total of 309 individual reptiles, mostly lizards and snakes, belonging to 12 species (American alligator, six lizard species, five snake species) was captured on St. Catherine's Island, Liberty County, Georgia, USA, and examined for ticks. Three lizard species, the broad-headed skink Eumeces laticeps, southeastern 5-lined skink Eumeces inexpectatus, and eastern glass lizard Ophisaurus ventralis, were severely infested with larvae and nymphs of the blacklegged tick, Ixodes scapularis. Ticks were not found on any of the other reptile species. Overall, 80% of 65 E. inexpectatus examined were parasitized by a mean intensity of 21.5larvae and 88% were parasitized by a mean intensity of 4.8 nymphs. Corresponding figures for E. laticeps (n=56) were 93% and 51.3 for larvae and 89% and 7.4 for nymphs, and for O. ventralis (n=3) were 67% and 22.5 for larvae and 100% and 21.3 for nymphs. Larvae and nymphs attached along the lateral grooves of O. ventralis. Nymphs attached mainly behind the ears and in the foreleg axillae whereas larvae mainly attached to these sites and on the hindlegs in Eumeces spp. Seasonally, both larvae and nymphs were recorded on lizards from April through October. A unimodal larval peak was recorded in May or June. Seasonal data for nymphs did not reveal any distinct peaks but small bimodal peaks in mean intensities may have occurred (one in early summer, the other in late summer)suggesting that some ticks complete their life cycle in one year, and others in two years, on St. Catherine's Island. Potential epidemiological consequences of these findings with respect to Lyme disease in the southeastern United States are briefly addressed.

Tissues of rodents and host-seeking adult ticks collected in the Piedmont, Sandhills, Coastal Plain, and Coastal Zone of South Carolina were cultured in attempts to isolate Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt & Brenner), the etiologic agent of Lyme disease. An exploratory, tree-based statistical analysis was used to identify ecological variables that were associated with spirochete infection among rodents and ticks. Spirochetes were isolated from tissues of 71 rodents: 22 (69%) of 32 eastern woodrats, 39 (53%) of 74 cotton mice, and 11 (25%) of 44 hispid cotton rats. Rodent infection prevalences were significantly higher in the Coastal Zone than in other regions. Spirochetes were also cultured from 31 (2.6%) of 1,193 questing ticks. Prevalence of spirochetes in Ixodes affinis Neumann (19/74, 26%) was significantly higher than in I. scapularis Say (12/864, 1.3%) and other species (0/255) of ticks tested. In addition, two (9%) of 23 adult I. minor Neumann removed from woodrats contained spirochetes. Isolates from rodents and ticks were analyzed immunologically by indirect immunofluorescence and Western blots, and further characterized by polymerase chain reaction assays and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. All were determined to be B. burgdorferi sensu lato. Results of this study confirmed that B. burgdorferi is endemic in South Carolina, and that enzootic transmission cycles exist at foci in the Coastal Zone. These findings add additional evidence that I. affinis and I. minor are potentially significant maintenance vectors of the spirochete.

The murine rodent, Sommeromys macrorhinos, new genus and species, is described from a single specimen collected at 2400 m near the summit of Gunung Tokala in central Sulawesi. The species is insectivorous and a member of the tropical upper montane rain forest fauna of the island. With its small body, elongate rostrum, long and slender hind feet, very long tail, and brownish gray fur, S. macrorhinos superficially resembles the long-tailed and small-bodied shrew rat, Tateomys macrocercus, another Sulawesian upper montane forest endemic. Sommeromys macrorhinos, however, possesses a combination of derived external, cranial, and dental traits, along with a unique rostral shape, that dissassociates it from any relationship with not only T. macrocercus and its close allies T. rhinogradoides and Melasmothrix naso, but with also the large-bodied shrew rats of Sulawesi (Echiothrix) and those indigenous to the Philippines (Archboldomys, Rhyncomys, Chrotomys, and Celaenomys) and New Guinea (Neohydromys, Pseu...

We document the first report of a blacklegged tick, Ixodes scapularis Say, parasitizing an American Kestrel, Falco sparverius Linnaeus (Falconiformes: Falconidae), in Canada. A fully engorged I. scapularis nymph was collected from the base of the tongue of an American Kestrel nestling recovered at Mirabel, Québec. This nestling had recently fledged the nest, and was exposed to I. scapularis immatures that were host-seeking in the surrounding low-level vegetation. DNA barcoding was used to confirm the identification of the tick. Primers of the flagellin (fla) gene were employed to determine whether the Lyme disease spirochete, Borrelia burgdorferi sensu lato (s.l.) Johnson, Schmid, Hyde, Steigerwalt & Brenner, was present in the I. scapularis nymph; the tick was negative. We provide the first report of I. scapularis parasitizing a raptor in Canada and, likewise, the first account of this tick species attached to the oral cavity of a bird. Moreover, this bird parasitism is the first documentation of a tick on a falconid bird in Canada.

Ectoparasitic arthropods are often vectors of rickettsiosis. We conducted a survey of ectoparasites on U.S. military facilities throughout Japan with the use of specimens submitted by pest control, public health, and veterinary personnel. Over 1,600 individual ectoparasites were collected. Fifteen species were identified, including several significant vectors of human diseases such as scrub typhus and rickettsial spotted fevers. These ectoparasites included Ctenocephalides felis, Haemaphysalis longicornis, Ixodes persulcatus, Leptotrombidium fuji, Leptotrombidium pallidum, and Rhipicephalus sanguineus. Rickettsial agents were detected by PCR and DNA sequencing. These included Bartonella henselae, Bartonella japonica, a novel Bartonella, Coxiella burnetii, an unnamed Coxiella, Ehrlichia canis, Orientia tsutsugamushi, Rickettsia typhi, and “Rickettsia Rf2125”/“Rickettsia cf1and5”.

Linognathus samburi n. sp. is described from adult male and female specimens collected from a juvenile female Gunther's dikdik (Madoqua guentheri) live-trapped near Olturot Village, Samburu district (Rift Valley Province) in northern Kenya. The new species is distinguished from other species of Linognathus including Linognathus geigyi and Linognathus damarensis, both of which parasitize Kirk's dikdik (Madoqua kirkii). A dichotomous key to the species of Linognathus that are known to parasitize dikdiks is included.

Ticks are obligate ectoparasites of terrestrial vertebrates (amphibians, reptiles, birds, and mammals). They belong to the class Arachnida, which as a group are distinguished from the class Insecta by having four pairs of legs as nymphs and adults, lacking both antennae and wings, and having two pairs of appendages associated with their mouthparts, i.e., chelicerae and pedipalps. All ticks and some mites are the only members of the Arachnida that are parasitic. In terms of size, ticks are the largest acarines and can be recognized by their dorsoventrally flattened appearance and by one component of the mouthparts, a hypostome with recurved teeth that acts as a holdfast organ, anchoring the tick to its host. They also possess a unique sensory apparatus, called Haller’s organ on the tarsus of each foreleg. Ticks can be divided into three families, the Argasidae (soft ticks), Ixodidae (hard ticks), and Nuttalliellidae. The last-named family includes a single species from Africa that is infrequently collected, but the other two families are widespread and include many species, some of which may bite humans. While several species of ticks may occasionally attach to humans, relatively few species commonly bite humans, and some of these are vectors of disease-causing pathogens. This chapter considers ticks that are frequently recorded as biting humans. It lists identification guides for ticks that occur in the world’s different zoogeographic regions.

A review of the literature and unpublished records from the U.S. National Tick Collection on the importation of ticks from foreign lands reveals that at least 99 exotic tick species assignable to 11 genera have been either detected and destroyed at ports of entry or inadvertently imported into the United States in the past half century. This number includes four argasid and 95 ixodid species, some of which are important vectors of agents that cause disease to both man and animals. If one includes Aponomma sp. and Hyalomma sp. and the subspecies of Rhipicephalus, the total exceeds 100 taxa. It is notable that the number of imported tick species recorded herein exceeds the total number of tick species native to the United States. It appears that the soft tick genera Argas, Antricola and Nothoaspis have not been imported, although at some point in time Argas persicus (Oken) was introduced because it is resident although not often collected. The hard tick genera Anomalohimalaya, Cosmiomma, Margaropus, Nosomma and Rhipicentor, and the nuttalliellid genus Nuttalliella have also not been imported.

A total of 152 ixodid ticks (Acari: Ixodidae) consisting of nine species was collected from 82 passerine birds (33 species) in 14 locations in Canada from 1996 to 2000. The Lyme disease spirochete Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwaldt & Brenner was cultured from the nymph of a blacklegged tick, Ixodes scapularis Say, that had been removed from a common yellowthroat, Geothlypis trichas L., from Bon Portage Island, Nova Scotia. As a result of bird movement, a nymphal I. scapularis removed from a Swainson's thrush, Catharus ustulatus incanus (Godfrey), at Slave Lake, Alberta, during spring migration becomes the new, most western and northern record of this tick species in Canada. Amblyomma longirostre Koch, Amblyomma sabanerae Stoll, and Ixodes baergi Cooley & Kohls are reported for the first time in Canada. Similarly, Amblyomma americanum L., Amblyomma maculatum Koch, and Ixodes muris Bishopp & Smith are reported for the first time on birds in Canada. After removal of an I. muris gravid female from a song sparrow, Melospiza melodia Wilson, at St. Andrews, New Brunswick, eggs were laid, which developed into larvae, and this new tick-host record demonstrates that birds have the potential to start a new tick population. We conclude that passerine birds disperse several species of ixodid ticks in Canada, and during spring migration translocate ticks from the United States, and Central and South America, some of which are infected with B. burgdorferi.

The adult male and female of Polyplax guatemalensis sp. n. are described from the sigmodontine murid rodent Peromyscus grandis Goodwin collected in the Reserva de Biosfera, Sierra de las Minas, Guatemala, at an elevation of 2,200 m. The new species extends the number of known native species of Polyplax in the New World to four with none of them recorded south of Panama. Polyplax guatemalensis is morphologically most closely related to Polyplax auricularis which parasitises a cluster of closely related New World sigmodontine rodents from Canada to Panama. These two species can be distinguished from all other known species of Polyplax by the presence of partially overlapping, subtriangular, anterior abdominal plates in both sexes. Polyplax guatemalensis can be separated from P. auricularis by the abundant tergal abdominal setae and longer pseudopenis in males, and by the presence of one fewer anterior abdominal, subtriangular tergite and sternite in females.

Southern flying squirrels (Glaucomys volans) from southeastern Georgia were examined for ectoparasites and gastrointestinal helminths. Ten species of ectoparasites were recovered, including 3 species of sucking lice (Hoplopleura trispinosa, Microphthirus uncinatus, and Neohaematopinus sciuropteri), 1 species of flea (Orchopeas howardi), 2 species of ticks (Amblyomma maculatum and Ixodes scapularis), 3 species of mesostigmatid mites (Androlaelaps casalis, A. fahrenholzi, and Haemogamasus ambulans), and 1 species of chigger (Leptotrombidium peromysci). Only the sucking lice and fleas were common on this host. M. uncinatus is reported for the first time from eastern North America. The 2 most commonly collected ectoparasites, N. sciuropteri (prevalence = 63%) and O. howardi (prevalence = 47%), have previously been shown to be vectors of the rickettsial zoonotic agent that causes sporadic epidemic typhus. Also, 3 nematodes (Citellinema bifurcatum, Strongyloides robusius, and Syphacia thompsoni), 1 unidentified cestode, and 1 acanthocephalan (Moniliformis clarki) were found in flying squirrel gastrointestinal tracts. With the exception of S. thompsoni, which was common and relatively abundant in the cecum (prevalence = 94%, intensity = 51+/-12), both the prevalence and intensity of helminth parasites were low. The nematode S. thompsoni and the acanthocephalan M. clarki are new state records for tree squirrels in Georgia.

From June 1993 through June 1996, 2,260 adult, 4,426 nymphal, and 2,178 larval lone star ticks Amblyomma americanum (L.) were collected in Missouri from vertebrate hosts and by dragging a cloth over vegetation. Prevalence, mean intensity, and relative abundance of each stage varied among hosts. The relative abundance of adult lone star ticks was highest on white-tailed deer, but this stage was also collected from raccoons, opossum, red fox, coyotes, and wild turkey. Nymphs were collected from gray squirrels, eastern cottontail rabbits, opossums, red fox, Carolina wren, and bobwhite quail, but the highest relative abundance occurred on wild turkey, white-tailed deer, and raccoons. Eastern cottontail rabbits, white-tailed deer, raccoons, and squirrels had the highest relative abundance of larval lone star ticks, but they were also found on opossums and wild turkey. The activity of adult lone star ticks was greatest from May through July. The activity for nymphs was highest from May through August, and for larvae, July through September.

Seven species of ticks (n=1,088) collected by dragging and from mammals captured in southeastern Missouri, USA, during 1995 and 1996, were tested by indirect and direct immunofluorescent assays for Borrelia species and B. burgdorferi. Variation occurred in the reactivities of various tick species and in four isolates from Missouri to species specific monoclonal antibodies (MAB) and polyclonal anti-Borrelia antibodies (PAB). MAB specific for B. burgdorferi were H5332 and H3TS for Osp A, H614 for Osp B and H605 for flagellin. The PAB labeled “Borrelia genus specific” cross-reacted with other spirochetes, specifically Leptospira and Treponema. The PAB labeled “B. burgdorferi specific” cross-reacted with B. turicatae and B. anserina. One Haemaphysalis leporispalustris and 19 Ixodes dentatus were positive for B. burgdorferi sensu stricto. Ten ticks were positive for B. burgdorferi sensu lato: 5 Amblyomma americanum, 1 H. leporispalustris, 3 I. dentatus, and 1 I. scapularis.

Human monocytic ehrlichiosis is an emerging zoonosis caused by infection with Ehrlichia chaffeensis Anderson, Dawson, Jones & Wilson, which is transmitted to mammals by ixodid ticks. Prevalence of infected ticks and distribution of infection foci indicate relative risk of human exposure to ehrlichiosis and may be influenced by factors such as geographic isolation, human disturbance, and the availability of suitable mammalian reservoir hosts. To test, this, individual and pooled lone star ticks, Amblyomma americanum (L.), were collected from three populations from the Georgia coast (1 mainland site and two barrier islands) and screened for E. chaffeensis. A species-specific, nested polymerase chain reaction (PCR) assay was used to amplify a 572 bp fragment of the E. chaffeensis 16S rRNA gene from infected ticks. PCR product specificity was confirmed by nucleotide sequencing. Our results showed the prevalence of infected ticks to be 0.0% (n = 151), 0.9% (n = 111), and 9.3% (n = 129) for Sapelo Island, St. Catherine's Island, and Fort McAllister, respectively.

Host attachment sites and frequency distribution of parasitism were investigated for the larval erythraeid mite Leptus indianensis parasitising a sample of 500 harvestmen, Leiobunum formosum in Tennessee, USA. A significant difference was found in the number of mites attached to different body segments of the harvestmen with the greatest number of mites attached to femurs I–IV. Scanning electron microscopy revealed that the mites attached to smooth areas of the host integument between rows of stout setae. The frequency distribution of mites parasitising the harvestman population was highly clumped (Coefficient of Dispersion = 3.34) with a relatively small number of hosts being parasitised by most of the mites.

Seven species of arthropods were recovered from 45 Brazilian free-tailed bats, Tadarida brasiliensis (I. Geoffrey), captured from May 1994 to May 1995 from a roost in Jenkins County, GA. Six species of mites were found infesting the bats, representing 5 families: Macronyssidae, Cheyletidae, Sarcoptidae, Rosensteiniidae, and Uropodidae. The macronyssid mite chiroptonyssus robustipes (Ewing) and the hemipteran bat bug, Cimex adjunctus (Barber), were collected from the host and the roost. C. robustipes was the most abundant mite (2,508 specimens) and the macronyssid Steatonyssus ceratognathus (Ewing) (189 specimens) was the 2nd most abundant mite found infesting the bats. The predatory cheyletid mite Cheyletonella vespertilionis Womersley (51 specimens) was also collected from the bats, and this is thought to be the 1st report of this mite from Georgia. In addition, Teinocoptes sp. (Sarcoptidae, 8 specimens), Nycteriglyphus sp. (Rosensteiniidae, 8 specimens), and uropodid mites (5 specimens) were removed from the bats. Of the 45 bats examined, all 30 females and 14 of 15 males were infested with C. robustipes. Twenty-three bat anatomical areas were designated and all C. robustipes mites were counted to ascertain anatomical preference. This mite was significantly more abundant on the ventral wing membrane areas posterior to the radiusulna and on the lower torso. Protonymphs of C. robustipes predominated on the wing membranes of the bats, whereas adult mites were more concentrated on the torso and head.

From June 1995 through January 1998, 677 tick specimens were submitted by 521 humans from 14 states. Analysis was limited to specimens originating in Georgia and South Carolina, representing 87.3% of total submissions. Attachment sites were specified in 367 specimens (62.3%). The American dog tick, Dermacentor variabilis (Say), a vector of the agent of Rocky Mountain spotted fever, favored the head and neck in 59% of attached specimens. The lone star tick, Amblyomma americanum (L.), a strongly implicated vector of the agent of human monocytic ehrlichiosis, favored the lower extremities, buttocks, and groin in 54% of specimens. The blacklegged tick, Ixodes scapularis Say, the main eastern vector of the Lyme disease spirochete, had widely distributed attachment sites with no apparent site preference. The Gulf Coast tick, A. maculatum Koch, parasitized humans in too few instances for analysis. In the southeastern United States, prevention of tick bites and tickborne illnesses such as Rocky Mountain spotted fever, ehrlichiosis, and Lyme disease may be enhanced by personal practices and public health measures based on knowledge of preferred attachment sites of potentially infectious tick species.

Robert Traub, the world's foremost authority on fleas and flea-borne diseases and one of the most accomplished and respected medical entomologists of his generation, was closely associated with the Journal of Medical Entomology from its founding in 1964. He served on the Journal's editorial board from 1964 to 1988, and many of his most important contributions graced its pages. Because this issue of the Journal of Medical Entomology is dedicated to him, we provide here a bibliography of his scientific publications. Just a glance at this list, which contains papers on fleas, mites, mosquitoes, leeches, even amebiasis, as well as on a vast range of host vertebrates, will instantly evidence Dr. Traub's central role in the history of 20th century parasitology. The list totals 207 citations spanning the years 1944–1998.

Robert Traub, ONE of the most accomplished and respected medical entomologists of this or any generation, died on 21 December 1996 at the National Naval Medical Center in Bethesda, MD, after an extended illness. Although he is best known for his encyclopedic knowledge of fleas, his name stands for much more. He leaves a legacy of pioneering research accomplishments in several disciplines, especially flea systematics, chigger taxonomy, and the epidemiology of both scrub typhus and murine typhus. Because Dr. Traub was instrumental in founding the Journal of Medical Entomology in 1964 in which several of his substantial manuscripts were published, it is appropriate to present his obituary here and to dedicate this issue of the journal to him.

Adults and nymphs of Amblyomma exornatum Koch (Acari: Ixodidae), an exotic African tick of monitor lizards, were collected from a Gray’s monitor lizard, Varanus olivaceus Hallowell, that died in a reptile facility in Alabama. Nine adult ticks were tested by polymerase chain reaction for rickettsial agents. DNA from a novel spotted fever group Rickettsia was amplified and sequenced from one of the nine ticks. The novel Rickettsia was most similar to “Rickettsia anan,” which is associated with Amblyomma from Asia. The detection of a spotted fever group Rickettsia in exotic ticks emphasizes the potential threat posed by the importation and propagation of exotic animals in the United States.

Two species of reptile ticks, Amblyomma dissimile Koch and Amblyomma torrei Pérez Vigueras (Acari: Ixodidae), are reported from the Bahama Islands for the first time. The widespread neotropical (including the Caribbean and southern Florida) A. dissimile was recovered on Andros Island from three species of reptiles all for the first time: the Andros iguana Cyclura cychlura cychlura Cuvier, the Andros curly tail lizard Leiocephalus carinatus coryi Schmidt, and the Andros boa Epicrates striatus fowleri Sheplan and Schwartz. The iguana tick A. torrei, previously known only from Cuba, Puerto Rico and the Cayman Islands, was recovered in the Exuma Islands from the Exuma iguana Cyclura cychlura figginsi Barbour. Mean numbers of ticks per host were as high as 36.6 on Mangrove Cay, Andros Island, and 25.8 on Pasture Cay in the Exuma Islands.

Background: Amblyomma cajennense F. is one of the best known and studied ticks in the New World because of its very wide distribution, its economical importance as pest of domestic ungulates, and its association with a variety of animal and human pathogens. Recent observations, however, have challenged the taxonomic status of this tick and indicated that intraspecific cryptic speciation might be occurring. In the present study, we investigate the evolutionary and demographic history of this tick and examine its genetic structure based on the analyses of three mitochondrial (12SrDNA, d-loop, and COII) and one nuclear (ITS2) genes. Because A. cajennense is characterized by a typical trans-Amazonian distribution, lineage divergence dating is also performed to establish whether genetic diversity can be linked to dated vicariant events which shaped the topology of the Neotropics. Results: Total evidence analyses of the concatenated mtDNA and nuclear + mtDNA datasets resulted in well-resolved and fully congruent reconstructions of the relationships within A. cajennense. The phylogenetic analyses consistently found A. cajennense to be monophyletic and to be separated into six genetic units defined by mutually exclusive haplotype compositions and habitat associations. Also, genetic divergence values showed that these lineages are as distinct from each other as recognized separate species of the same genus. The six clades are deeply split and node dating indicates that they started diverging in the middle-late Miocene. Conclusions: Behavioral differences and the results of laboratory cross-breeding experiments had already indicated that A. cajennense might be a complex of distinct taxonomic units. The combined and congruent mitochondrial and nuclear genetic evidence from this study reveals that A. cajennense is an assembly of six distinct species which have evolved separately from each other since at least 13.2 million years ago (Mya) in the earliest and 3.3 Mya in the latest lineages. The temporal and spatial diversification modes of the six lineages overlap the phylogeographical history of other organisms with similar extant trans-Amazonian distributions and are consistent with the present prevailing hypothesis that Neotropical diversity often finds its origins in the Miocene, after the Andean uplift changed the topology and consequently the climate and ecology of the Neotropics. EEA Rafaela Fil: Beati, Lorenza. Georgia Southern University. Institute for Coastal Plain Science. United States National Tick Collection; Estados Unidos Fil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina Fil: Burkman, Erica J. Georgia Southern University. Institute for Coastal Plain Science. United States National Tick Collection; Estados Unidos. University of Georgia. College of Veterinary Medicine. Department of Infectious Diseases; Estados Unidos Fil: Barros Battesti, Darci M. Governo Do Estado de Sao Paulo. Secretaria Da Saude. Instituto Butantan. Laboratório de Parasitologia; Brasil Fil: Labruna, Marcelo B. Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Medicina Veterinária Preventiva e Saúde Animal; Brasil Fil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Regional Agropecuaria Rafaela; Argentina Fil: Cáceres, Abraham G. Universidad Nacional Mayor de San Marco. Facultad de Medicina. Departamento Académico de Microbiologia Médica; Perú. Instituto Nacional de Salud. Laboratorio de Entomología; Perú Fil: Guzman Cornejo, Carmen. Universidad Nacional Autónoma de México. Facultad de Ciencias. Departamento de Biología Comparada. Laboratorio de Acarología; México Fil: Léon, Renato. Universidad San Francisco de Quito. Colegio de Ciencias Biológicas y Ambientales. Laboratorio de Entomología Médica y Medicina Tropical (LEMMT); Ecuador Fil: Durden, Lance A. Georgia Southern University. Biology Department; Estados Unidos Fil: Faccini, João L.H. Universidade Federal Rural do Rio de Janeiro. Instituto de Veterinária. Departamento de Parasitologia Animal; Brasil

First Detection of Lyme Disease Spirochete Borrelia burgdorferi in Ticks Collected from a Raptor in Canada During a pan-Canadian tick-host study, we detected the spirochetal bacterium, Borrelia burgdorferi sensu lato, which causes Lyme disease, in ticks collected from a raptor. Lyme disease is one of a number of zoonotic, tick-borne diseases causing morbidity and mortality worldwide. Larvae of the avian coastal tick, Ixodes auritulus, were collected by wildlife rehabilitators from a Cooper’s hawk, Accipiter cooperii, on Vancouver Island, British Columbia. Using PCR amplification of the linear plasmid ospA gene of B. burgdorferi, 4 (18%) of 22 larvae were positive.

Sucking lice (Phthiraptera: Anoplura) are obligate blood-feeding ectoparasites of placental mammals including humans. Worldwide, more than 550 species have been described and many are specific to a particular host species of mammal [1]. Three taxa uniquely parasitize humans: the head louse, body louse, and crab (pubic) louse. The body louse, in particular, has epidemiological importance because it is a vector of the causative agents of three important human diseases: epidemic typhus, trench fever, and louse-borne relapsing fever. Since the advent of antibiotics and more effective body louse control measures in the 1940s, these diseases have markedly diminished in incidence. However, due to 1) increasing pediculicide resistance in human lice, 2) reemergence of body louse populations in some geographic areas and demographic groups, 3) persistent head louse infestations, and 4) recent detection of body louse-borne pathogens in head lice, lice and louse-borne diseases are an emerging problem worldwide. This mini-review is focused on human body and head lice including their biological relationship to each other and its epidemiological relevance, the status and treatment of human louse-borne diseases, and current approaches to prevention and control of human louse infestations.

The dilemma of preserving the parasite biodiversity of rare, endangered, or extinct hosts has been highlighted recently (Windsor 1990, 1995; Rozsa 1992; Stork & Lyal 1993). Host cxtinction also results in cocxtinction in nature of all associated hostspccific parasites. Further, visible ectoparasites often are removed purposely from rare or endangcred animlas with an aim towards increasing host fitness and survival. Because the number of parasitic species may be about four times that of free-living species on earth (May 1992), such practices could have dire consequences for parasite te biodiversity, which represents a significant proportion of total biodiversity. Negative human perception of parasites, in addition to the typically small size of the latter, has hindered the conservation of rare parasites and actually has decreased the abundance of certain species.

The U.S. National Tick Collection (USNTC) is unparalleled by other tick collections. It includes more than a million tick specimens in over 121,000 individual accessioned collections. Most of the world's approximately 850 described tick species and more than 300 types are included in the collection. These attributes dwarf other tick collections, and it is believed that the USNTC is larger than all other world tick collections combined. As a resource for identification purposes, systematics research, and the investigation of tickrelated problems of humans and animals, this tick collection is unrivaled and is a national treasure. If it were to be lost, it would be impossible to replace.

In far-western Canada, gallinaceous birds are hosts of hard ticks (Ixodida: Ixodidae) that can carry zoonotic pathogens. In this study, we collected the avian coastal tick, Ixodes auritulus Neumann, the western blacklegged tick, Ixodes pacificus Cooley & Kohls, and Ixodes spinipalpis Hadwen & Nuttall, from gallinaceous birds on Vancouver Island, British Columbia. Notably, we provide the first records of these three tick species on California Quail, Callipepla californica (Shaw), in Canada. We document the first records of I. auritulus parasitizing Sooty Grouse, Dendragapus fulginosis (Ridway). Moreover, we furnish the first report of I. spinipalpis on a quail. An I. pacificus nymph was collected from a California Quail, and it was positive for the Lyme disease bacterium, Borrelia burgdorferi sensu lato (s.l.) Johnson, Schmid, Hyde, Steigerwalt & Brenner. Using PCR on the nymphal extract and DNA sequencing on the borrelial amplicon, we specifically detected B. burgdorferi sensu stricto (s.s.), a genospecies pathogenic to humans and certain domestic animals. Since some ground-dwelling birds are involved in the enzootic maintenance of Lyme disease, veterinarians, wildlife rehabilitators, hunters, and health-care providers should be vigilant that gallinaceous birds may play a role in the enzootic transmission of B. burgdorferi s.l. in Canada.

Patterns of host–parasite association are poorly understood in tropical forests. While we typically observe only snapshots of the diverse assemblages and interactions under variable conditions, there is a desire to make inferences about prevalence and host-specificity patterns. We studied the interaction of ticks with non-volant small mammals in forests of Borneo. We inferred the probability of species interactions from individual-level data in a multi-level Bayesian model that incorporated environmental covariates and advanced estimates for rarely observed species through model averaging. We estimated the likelihood of observing particular interaction frequencies under field conditions and a scenario of exhaustive sampling and examined the consequences for inferring host specificity. We recorded a total of 13 different tick species belonging to the five genera Amblyomma, Dermacentor, Haemaphysalis, Ixodes, and Rhipicephalus from a total of 37 different host species (Rodentia, Scandentia, Carnivora, Soricidae) on 237 out of 1,444 host individuals. Infestation probabilities revealed most variation across host species but less variation across tick species with three common rat and two tree shrew species being most heavily infested. Host species identity explained ca. 75 % of the variation in infestation probability and another 8–10 % was explained by local host abundance. Host traits and site-specific attributes had little explanatory power. Host specificity was estimated to be similarly low for all tick species, which were all likely to infest 34–37 host species if exhaustively sampled. By taking into consideration the hierarchical organization of individual interactions that may take place under variable conditions and that shape host–parasite networks, we can discern uncertainty and sampling bias from true interaction frequencies, whereas network attributes derived from observed values may lead to highly misleading results. Multi-level approaches may help to move this field towards inferential approaches for understanding mechanisms that shape the strength and dynamics in ecological networks.

Domestic dogs, Canis lupus, have been one of the longest companions of humans and have introduced their own menagerie of parasites and pathogens into this relationship. Here, we investigate the parasitic load of 212 domestic dogs with fleas (Siphonaptera) chewing lice (Phthiraptera), and ticks (Acarina) along a gradient from rural areas with near-natural forest cover to suburban areas in Northern Borneo (Sabah, Malaysia). We used a spatially-explicit hierarchical Bayesian model that allowed us to impute missing data and to consider spatial structure in modelling dog infestation probability and parasite density. We collected a total of 1,968 fleas of two species, Ctenocephalides orientis and Ctenocephalides felis felis, from 195 dogs (prevalence, 92 %). Flea density was higher on dogs residing in houses made of bamboo or corrugated metal (increase of 40 % from the average) compared to timber or stone/compound houses. Host-dependent and landscape-level environmental variables and spatial structure only had a weak explanatory power. We found adults of the invasive chewing louse Heterodoxus spiniger on 42 dogs (20 %). The effect of housing conditions was opposite to those for fleas; lice were only found on dogs residing in stone or timber houses. We found ticks of the species Rhipicephalus sanguineus as well as Haemaphysalis bispinosa gp., Haemaphysalis cornigera, Haemaphysalis koenigsbergi, and Haemaphysalis semermis on 36 dogs (17 %). The most common tick species was R. sanguineus, recorded from 23 dogs. Tick infestations were highest on dogs using both plantation and forest areas (282 % increase in overall tick density of dogs using all habitat types). The infestation probability of dogs with lice and ticks decreased with elevation, most infestations occurred below 800 m above sea level. However, the density of lice and ticks revealed no spatial structure; infestation probability of dogs with these two groups revealed considerable autocorrelation. Our study shows that environmental conditions on the house level appeared to be more influential on flea and lice density whereas tick density was also influenced by habitat use. Infestation of dogs with Haemaphysalis ticks identified an important link between dogs and forest wildlife for potential pathogen transmission.

The authors present an introductory overview of the principal groups of ectoparasites (flukes, leeches, crustaceans, insects, arachnids, lampreys and vampire bats) associated with domestic animals. Currently-accepted higher-level classifications are outlined for these parasites. Almost all significant ectoparasites of domestic animals are invertebrates, the majority being arthropods (crustaceans, insects and arachnids). Some of these ectoparasites are of particular importance as vectors of pathogens. Many ectoparasite species are host-specific, and vector species typically transmit characteristic pathogens.

The larva, nymph, and female of Ixodes (Ixodes) venezuelensis are diagnosed using scanning electron microscopy, and the larva is described for the first time. This ixodid tick is recorded from the northern neotropics as a parasite of five species of didelphid marsupials and eighteen species of rodents (one sciurid, two heteromyids, eleven murids, two dasyproctids, and two echimyids). Collection records of I. venezuelensis are presented for Costa Rica, Colombia, Panama and Venezuela, with the Costa Rican records being new and extending the known range of this tick by at least 300 km. Altitudinally, I. venezuelensis has been collected between elevations of 24 and 2410 m with most collections between 100 and 800 m. The possibility that I. venezuelensis may be parthenogenetic is discussed.

From January 1998 through September 1999, 324 dogs in three northwestern Georgia counties were examined for ticks. Six species of ticks were recovered. The three most commonly collected ticks were the American dog tick, Dermacentor variabilis (Say) (310 male male, 352 female female; prevalence, 97%; mean intensity 2.1); the brown dog tick, Rhipicephalus sanguineus (Latreille) (118 male male, 119 female female, 38 nymphs; prevalence, 22%; mean intensity, 3.8); and the lone star tick, Amblyomma americanum (L.) (8 male male 26 female female, 2 nymphs; prevalence, 5%; mean intensity, 2.4). Other ticks recovered were Ixodes cookei Packard (3 female female); the Gulf Coast tick, Amblyomma maculatum Koch (2 female female); and the blacklegged tick, Ixodes scapularis Say (1 female). Another adult female specimen of I scapularis was recovered from a cat, further reinforcing that this medically important tick is present in northwestern Georgia.

Millions of Lyme disease vector ticks are dispersed annually by songbirds across Canada, but often overlooked as the source of infection. For clarity on vector distribution, we sampled 481 ticks (12 species and 3 undetermined ticks) from 211 songbirds (42 species/subspecies) nationwide. Using PCR, 52 (29.5%) of 176 Ixodes ticks tested were positive for the Lyme disease spirochete, Borrelia burgdorferi s.l. Immature blacklegged ticks, Ixodes scapularis, collected from infested songbirds had a B. burgdorferi infection prevalence of 36% (larvae, 48%; nymphs, 31%). Notably, Ixodes affinis is reported in Canada for the first time and, similarly, Ixodes auritulus for the initial time in the Yukon. Firsts for bird-parasitizing ticks include I. scapularis in Quebec and Saskatchewan. We provide the first records of 3 tick species cofeeding on passerines (song sparrow, Swainson's thrush). New host records reveal I. scapularis on the blackpoll warbler and Nashville warbler. We furnish the following first Canadian reports of B. burgdorferi-positive ticks: I. scapularis on chipping sparrow, house wren, indigo bunting; I. auritulus on Bewick's wren; and I. spinipalpis on a Bewick's wren and song sparrow. First records of B. burgdorferi-infected ticks on songbirds include the following: the rabbit-associated tick, Ixodes dentatus, in western Canada; I. scapularis in Quebec, Saskatchewan, northern New Brunswick, northern Ontario; and Ixodes spinipalpis (collected in British Columbia). The presence of B. burgdorferi in Ixodes larvae suggests reservoir competency in 9 passerines (Bewick's wren, common yellowthroat, dark-eyed junco, Oregon junco, red-winged blackbird, song sparrow, Swainson's thrush, swamp sparrow, and white-throated sparrow). We report transstadial transmission (larva to nymph) of B. burgdorferi in I. auritulus. Data suggest a possible 4-tick, i.e., I. angustus, I. auritulus, I. pacificus, and I. spinipalpis, enzootic cycle of B. burgdorferi on Vancouver Island, British Columbia. Our results suggest that songbirds infested with B. burgdorferi-infected ticks have the potential to start new tick populations endemic for Lyme disease. Because songbirds disperse B. burgdorferi-infected ticks outside their anticipated range, health-care providers are advised that people can contract Lyme disease locally without any history of travel. Birds act as hosts of several species of hard ticks (Acari: Ixodidae) that may be infected with tick-borne, pathogenic microorganisms. East of the Rocky Mountains, the blacklegged tick, Ixodes scapularis Say, acts as the principal vector for the spirochetal bacterium Borrelia burgdorferi sensu lato (hereafter B. burgdorferi), the etiological pathogen of Lyme disease (Burgdorfer and Gage, 1986; Anderson, 1988; Sanders and Oliver, 1995). Collectively, at least 76 different passerines (Passeriformes) are known as avian hosts of immature (nymphs, larvae) I. scapularis. In far-western Northern America, the western blacklegged tick, Ixodes pacificus Cooley and Kohls, is ascribed as the primary vector of Lyme disease (Burgdorfer et al., 1985; Lane and Lavoie

Based on chaetotaxy of the dorsal shield, the taxonomic status of many species of Ornithonyssus has been considered invalid, resulting in the synonymy of all Brazilian Ornithonyssus from small terrestrial wild mammals into one of the following four species: Ornithonyssus bacoti (Hirst, 1913), Ornithonyssus matogrosso (Fonseca, 1954), Ornithonyssus pereirai (Fonseca, 1935) or Ornithonyssus wernecki (Fonseca, 1935). Despite the revision of this genus in 1980, including all known species worldwide, the knowledge of Ornithonyssus in Brazil has not progressed for more than 40 years. Considering the potential importance of these haematophagous mites in transmitting rickettsial disease agents to animals and humans, we have revised Ornithonyssus species collected from small mammals in Brazil by means of morphological and molecular studies. Types and other material deposited in the Acari Collection of the Instituto Butantan (IBSP) were examined in addition to recently collected specimens. Morphological and genetic analysis of the 16S rDNA mitochondrial gene revealed that small terrestrial mammals in Brazil are parasitized by six species of Ornithonyssus mites: Ornithonyssus brasiliensis (Fonseca, 1939), O. matogrosso, O. monteiroi (Fonseca, 1941), O. pereirai, O. vitzthumi (Fonseca, 1941), and O. wernecki. An illustrated key to females of the valid Brazilian species of Ornithonyssus is included, based on optical and scanning electron microscopy.

Adults and nymphs of a soft tick, Ornithodoros sonrai Sautet & Witkowski, were allowed to feed on suckling mice that had been experimentally infected with Crimean-Congo hemorrhagic fever (CCHF) virus (IbAr 10200 strain). The mean viral titer of mouse blood at the time of tick feeding was 10(3.2) plaque-forming units (PFU) per ml. Samples of ticks were assayed on 12 occasions between days 0 and 31 after the viremic blood meal. Mean CCHF viral titers were 10(2.1) PFU per tick immediately after the viremic meal but declined to 10(1.2) PFU per tick after 2 d, and no virus was detected beyond 8 d. The percentage of ticks with detectable virus was 92% (22/24) immediately after the viremic meal, but then declined to 20% (2/10) after 4 d and to 0% (0/44) after 11 or more days. Ticks were allowed to feed on sets of three naive suckling mice on days 0, 2, 5, 8, 11, 14, 21, and 28 after the viremic blood meal, but CCHF viral transmission did not occur. Similarly, no transovarial transmission of virus from CCHF virus-exposed O. sonrai to their progeny was observed. These results strongly indicate that O. sonrai is not a vector of CCHF virus.

Pools of adult female chicken mites, Dermanyssus gallinae (De Geer), were allowed to feed on chicks that had been inoculated with eastern equine encephalomyelitis (EEE) virus and that had a viremia level of 10(6.2)-10(6.6) plaque-forming units per milliliter of blood. Virus remained detectable by plaque assay in samples of these mites for 30 d after the infectious blood meal. Virus was not recovered from any of 151 progeny of virus-exposed female mites. Mites that had fed on viremic chicks were allowed to feed on naive chicks 3, 7, 11, 15, or 30 d later. EEE virus was transmitted to chicks by these mites on days 3 (one transmission in four trials) and 7 (one transmission in four trials). Both transmissions were confirmed by the presence of virus in chick blood 24-72 h after mites had fed, and by plaque-reduction neutralization assays of 21-d convalescent chick sera against the original viral strain.