New species records of Quadraseta Brennan, 1970 (Trombidiformes: Trombiculidae) in South America

The genus Quadraseta Brennan, 1970 (Trombiculidae) is distributed in South American, with a few records from Central America. The larvae (chiggers) are primarily mammal parasites, with one species from birds. Examination of unidentified material at US National Insect and Mite Collection revealed five species to this genus: Q. brasiliensis Goff & Gettinger, 1989, Q. falconensis Goff & Brennan, 1977, Q. flochi (Brennan & Jones, 1960), Q. mackenziei (Yunker & Brennan 1964), and Q. mirandae Goff & Brennan, 1977. This study resulted in new South American localities and host records for these species.

A new locality record for Radfordiella desmodi radovsky, 1967 (Mesostigmata: Macronyssidae) parasitizing the vampire bat in Brazil

Macronyssid mites are ectoparasites of reptiles, birds, and mammals (mainly bats). Out of 35 genera in this family, Radfordiella Fonseca, 1948 is a genus from the Neotropical region with six valid species, found parasitizing phyllostomid bats. Only Radfordiella desmodi Radovsky, 1967 and Radfordiella oudemansi Fonseca, 1948 have been registered in Brazil. The present study provides a new locality record for the species R. desmodi, microscopy images to aid in the identification, and a distribution map.

Records of ticks (Acari: Ixodidae) on humans and distribution of spotted-fever cases and its tick vectors in Paraná State, southern Brazil.

Brazilian spotted fever (BSF) is the deadliest rickettsiosis in the world. Although the epidemiology of the disease has been established in Brazil, there are still limited data available on distribution of tick vectors and tick species parasitizing humans in the country, particularly in Paraná State. The State of Paraná is located in the southern region of the country and is covered by two biomes: Atlantic rainforest and Cerrado. Thus, the aims of this study were i) to map the distribution of SF tick vectors, ii) to describe and map the distribution of human parasitism by ticks, and iii) to map the distribution of fatal and non-fatal spotted fever (SF) cases in Paraná State, southern Brazil. Data were reviewed and compiled from previous published reports, and also from two scientific collections of Paraná State. SF cases were retrieved from the Brazilian Notifiable Diseases Information System. A total of 50 cases of human parasitism by ticks were recorded, with a total of 64 (22 males, 12 females, 30 nymphs) ticks collected. The following 12 tick species were identified: Amblyomma aureolatum, Amblyomma brasiliense, Amblyomma calcaratum, Amblyomma dubitatum, Amblyomma incisum, Amblyomma longirostre, Amblyomma ovale, Amblyomma parkeri, Amblyomma scalpturatum, Amblyomma sculptum, Haemaphysalis juxtakochi and Rhipicephalus sanguineus sensu lato (s.l.). The most prevalent tick species associated to cases of human parasitism were A. sculptum (13/50; 26 %), A. aureolatum (10/50; 20 %), A. brasiliense (5/50; 10 %), A. ovale (5/50; 10 %) and A. parkeri (4/50; 8%). A total of 51 non-fatal and five fatal SF cases were recorded. Data from this study highlights the need for monitoring ticks parasitizing humans aiming early detection of tick-borne diseases cases, particularly BSF in Paraná State, southern Brazil.

Description of a new species of Ixodes (Acari: Ixodidae) and first report of Ixodes lasallei and Ixodes bocatorensis in Brazil.

In a recent study, we relegated the taxon Ixodes aragaoi Fonseca, 1935 to a junior synonym of Ixodes fuscipes Koch, 1844, and reinstated Ixodes spinosusNeumann, 1899 (a former synonym of I. fuscipes) to a valid species. We examined all lots of ticks formerly identified as I. fuscipes or I. aragaoi in three tick collections of Brazil. Through morphological analysis, some of the examined specimens could not be assigned to either I. fuscipes or I. spinosus based on the examination of the type specimens of these two species. Herein, we report these ticks to represent three different species: Ixodes catarinensis n. sp. Onofrio & Labruna, Ixodes lasalleiMéndez Arocha and Ortiz, 1958, and Ixodes bocatorensisApanaskevich and Bermúdez, 2017. The latter two species are reported for the first time in Brazil. Phylogenetic analysis inferred from the tick 16S rRNA gene partial sequences corroborated our morphological analysis, indicating that I. spinosus, I. lasallei, I. bocatorensis, and I. catarinensis n. sp. form a natural group of neotropical ticks. With the present study, the number of Ixodes species in Brazil increases from 9 to 12. We propose a new identification key for females and males of Ixodes species currently recognized in Brazil.

Synonymy of Ixodes aragaoi with Ixodes fuscipes, and reinstatement of Ixodes spinosus (Acari: Ixodidae).

Ixodes fuscipes Koch, 1844, described from Brazil, has been considered a valid species with records from Brazil and Peru. Ixodes spinosus Neumann, 1899, also described from Brazil, has been considered a synonym of I. fuscipes. In 2014, Ixodes aragaoi Fonseca, 1935 was redescribed as a valid species for Brazil and Uruguay. Until the present study, one major difference between the females of I. fuscipes and I. aragaoi was the horn-like auriculae in the former versus the ridge-like auriculae in the later, but this morphological difference was not supported after examination of the holotype of I. fuscipes and a syntype female of I. spinosus. Surprisingly, we found the type of I. fuscipes to have ridge-like auriculae, in contrast to the horn-like auriculae of I. spinosus. Comparisons of the I. fuscipes holotype with the syntypes of I. aragaoi revealed that they correspond to the same species. Therefore, we redescribe I. fuscipes, relegate I. aragaoi to a junior synonym of I. fuscipes, and reinstate I. spinosus as a valid species. After examining all lots of I. fuscipes in four tick collections, no specimen was recognized as I. fuscipes when compared with the type specimen of this taxon. On the other hand, specimens previously identified as I. aragaoi are now confirmed as I. fuscipes, with bona fide records for Brazil and Uruguay. Some of the specimens previously reported as I. fuscipes are now confirmed as I. spinosus, with records in two Brazilian biomes, Amazon and Atlantic rainforest. We present lists of the ticks examined in this study, with their current taxonomic status.

The geographic distribution of Argas (Persicargas) miniatus and Argas (Persicargas) persicus (Acari: Argasidae) in America, with morphological and molecular diagnoses from Brazil, Chile and Cuba.

High similarity of morphological traits has historically overshadowed the identities and distributions of poultry-associated soft ticks Argas (Persicargas) miniatus and Argas (Persicargas) persicus in America. In order to model the occurrence of both parasites in the continent, in the current study we performed morphological and molecular analyses to identify ticks collected in hen houses from Brazil and northern Chile. Combining these results with literature data, and the examination of Argas allotments deposited in the tick collections "Coleção Nacional de Carrapatos Danilo Gonçalves Saraiva" (Brazil), the "Coleção Acarológica do Instituto Butantan São Paulo" (Brazil), and the "Colección Zoológica de la Academia de Ciencia de Cuba" (Cuba), we present a critical list with the localities where A. (P.) miniatus and A. (P.) persicus have been reported in the American continent. Our results confirmed the presence of A. (P.) miniatus in Brazil and Cuba, and A. (P.) persicus in Chile, which in particular, constitutes the first molecularly confirmed report of the later species for South America. Although A. (P.) miniatus and A. (P.) persicus have been documented in 21 American countries, the identity of some reports must still be considered as uncertain until detailed morphological and/or molecular studies are performed. When contrasted to a Köppen-Geiger climate classification, A. (P.) miniatus predominantly occurs in equatorial and A. (P.) persicus in arid climates. However, until undetermined reports of both species are correctly identified, any conclusion on their geo-climatological occurrence throughout the American continent would be rather speculative.

Geographical distribution of Amblyomma cajennense (sensu lato) ticks (Parasitiformes: Ixodidae) in Brazil, with description of the nymph of A. cajennense (sensu stricto).

BACKGROUND: Until recently, Amblyomma cajennense (Fabricius, 1787) was considered to represent a single tick species in the New World. Recent studies have split this taxon into six species. While the A. cajennense species complex or A. cajennense (sensu lato) (s.l.) is currently represented by two species in Brazil, A. cajennense (sensu stricto) (s.s.) and Amblyomma sculptum Berlese, 1888, their geographical distribution is poorly known. METHODS: The distribution of the A. cajennense (s.l.) in Brazil was determined by morphological examination of all lots of A. cajennense (s.l.) in two large tick collections of Brazil, and by collecting new material during three field expeditions in the possible transition areas between the distribution ranges of A. cajennense (s.s.) and A. sculptum. Phylogenetic analysis inferred from the ITS2 rRNA gene was used to validate morphological results. Morphological description of the nymphal stage of A. cajennense (s.s.) is provided based on laboratory-reared specimens. RESULTS: From the tick collections, a total 12,512 adult ticks were examined and identified as 312 A. cajennense (s.s.), 6,252 A. sculptum and 5,948 A. cajennense (s.l.). A total of 1,746 ticks from 77 localities were collected during field expeditions, and were identified as 249 A. cajennense (s.s.), 443 A. sculptum, and 1,054 A. cajennense (s.l.) [these A. cajennense (s.l.) ticks were considered to be males of either A. cajennense (s.s.) or A. sculptum]. At least 23 localities contained the presence of both A. cajennense (s.s.) and A. sculptum in sympatry. DNA sequences of the ITS2 gene of 50 ticks from 30 localities confirmed the results of the morphological analyses. The nymph of A. cajennense (s.s.) is morphologically very similar to A. sculptum. CONCLUSION: Our results confirmed that A. cajennense (s.l.) is currently represented in Brazil by only two species, A. cajennense (s.s.) and A. sculptum. While these species have distinct distribution areas in the country, they are found in sympatry in some transition areas. The current distribution of A. cajennense (s.l.) has important implications to public health, since in Brazil A. sculptum is the most important vector of the bacterium Rickettsia rickettsii, the etiological agent of Brazilian spotted fever.

New records of Amblyomma goeldii (Acari: Ixodidae) and description of the nymphal stage.

Since its original description from the Amazonian region, the tick species Amblyomma goeldii Neumann, 1899 has been misidentified with Amblyomma rotundatum Koch, 1844 in different countries of the Neotropical region. Because of this, some authors have considered that the only confirmed records of A. goeldii were from French Guyana. Herein, we reviewed all specimens of A. goeldii that have been deposited at two tick collections in Brazil. In addition, we describe the nymphal stage of A. goeldii for the first time. A total of 10 unpublished records of the adult stage of A. goeldii are recorded from the Amazonian region of Brazil, confirming the occurrence of A. goeldii in this country. Except for one record on the snake Boa constrictor Linnaeus, all records of A. goeldii reported in the present study were from anteaters (Pilosa: Myrmecophagidae). Our results, in conjunction with previous literature records, indicate that anteaters and large snakes are important hosts for the adult stage of A. goeldii. The nymph of A. goeldii is morphologically similar to the nymphs of Amblyomma romitii Tonelli-Rondelli, 1939, Amblyomma dissimile Koch, 1844, and A. rotundatum. We present a modification of a previously published taxonomic key of Amblyomma nymphs from Brazil, in order to perform taxonomic identification of the nymph of A. goeldii based on external morphology. The geographical distribution of A. goeldii appears to be restricted to the Amazonian region. There were no previous host records for the immature stages of A. goeldii, thus it is expected that the present nymphal description will facilitate further works on the ecology of this poorly studied tick species.

Interaction of ectoparasites (Mesostigmata, Phthiraptera and Siphonaptera) with small mammals in Cerrado fragments, western Brazil.

We describe ectoparasite fauna associated with small mammals in fragments of Cerrado biome, central-western Brazil. We analyzed the level of associations and the aggregation patterns according to seasonal and host variations. Small mammals were systematically captured in 54 woodland fragments from February 2012 to July 2013. A total of 1040 animals belonging to eight marsupial and 12 rodent species were sampled; 354 individuals were parasitized by 33 ectoparasite species (twenty five Mesostigmata, seven Phthiraptera and one Siphonaptera). A total of 49 ecological relationships between ectoparasites and small mammals were observed, 24 being new association records. The overall specialization index of all ectoparasites and host species was 0.91 with significant deviation from a random host-parasite association, suggesting a high host-parasite specialization in this system. Specialization indices for ectoparasites ranged from moderate to high, while among host was high, for most species. Contrary to the overall pattern, some ectoparasites had higher prevalence and mean intensity of infestation in the dry season. Overall, ectoparasite prevalence and mean intensity of infestation were not significantly associated with host gender. This study provides significant information about the ectoparasites ecology in relation to specificity, seasonality and hosts gender, contributing to the understanding of host-parasite relationships in Brazilian savannah.

Validation of the taxon Ixodes aragaoi Fonseca (Acari: Ixodidae) based on morphological and molecular data.

The species Ixodes aragaoi Fonseca was described as Ixodes ricinus aragaoi, and later placed in synonymy with Ixodes affinis. However, this synonymy was rejected and the subspecies was elevated to species, and named as I. aragaoi. Some researchers did not consider the validity of I. aragaoi and maintained the synonymy proposed until 1998 when I. aragaoi was revalidated, and it was suggested that Ixodes pararicinus could be a synonym. The aim of this study was to confirm the taxonomic validity of I. aragaoi by means of redescription of adults and molecular analysis. Morphological studies were performed by optical and scanning electron microscopy; types of I. aragaoi were compared with those of I. pararicinus from Argentina, and also with material of I. pararicinus from Uruguay and I. affinis from the United States. Mitochondrial 16S rDNA sequences were obtained for determining phylogenetic relationships based on maximum parsimony. Morphological and molecular differences between I. aragaoi, I. pararicinus from Argentina, and I. affinis confirm the validity of the first each of these species. The morphological similarities of I. pararicinus from Uruguay with I. aragaoi, and the small distance of nucleotide sequences between them, confirm that the Uruguayan ticks are in fact I. aragaoi and expand the geographical distribution of this species. Based on the specimens of Ixodes examined in the present study, from the same locality of the types of I. ricinus rochensis in Uruguay, we agree with the synonymy of this subspecies with I. aragaoi as previously reported. Finally, our analyses indicate that both I. aragaoi and Ixodes fuscipes, another South American tick species, belong to the I. ricinus complex, currently composed of 19 species. 

Experimental infection with Rickettsia rickettsii in an Amblyomma dubitatum tick colony, naturally infected by Rickettsia bellii.

Amblyomma dubitatum engorged females, naturally infected by Rickettsia bellii, were used to establish a laboratory colony. Larvae, nymphs, and adults were exposed to two strains of Rickettsia rickettsii by feeding on needle-inoculated guinea pigs, and thereafter reared on uninfected guinea pigs. After acquisition feeding, engorged larvae and nymphs molted to nymphs and adults, respectively, which were shown to be infected (confirming transstadial perpetuation), and were able to transmit both strains of R. rickettsii to uninfected animals, as demonstrated by clinical, serological, and molecular analyses. However, the larval, nymphal, and adult stages of A. dubitatum showed to be only partially susceptible to R. rickettsii infection, since in all cases, only part of the ticks became infected by this agent, after being exposed to rickettsemic animals. While transovarial transmission of R. rickettsii was inefficient in the A. dubitatum engorged females of the present study, 100% of these females passed R. bellii transovarially. Because it has been reported that a primary infection by a Rickettsia species would preclude transovarial transmission of a second Rickettsia species, it is likely that the ineffectiveness of A. dubitatum to perpetuate R. rickettsii by transovarial transmission was related to its primary infection by R. bellii; however, it could also be related to unknown factors inherent to A. dubitatum. The relevance of A. dubitatum as a natural vector of R. rickettsii to humans or animals is discussed.

New records and human parasitism by Ornithodoros mimon (Acari: Argasidae) in Brazil.

The bat tick Ornithodoros mimon Kohls, Clifford & Jones is currently known by only few reports in Bolivia, Uruguay, Argentina, and the state of São Paulo in southeastern Brazil. Here, we expand the distribution of O. mimon in Brazil to the states of Minas Gerais (southeastern region), Goiás (central-western), Pernambuco, and Rio Grande do Norte (northeastern). Ticks were collected on human dwellings, where there had been repeated complains of tick bites on persons during the night. Tick bites were generally followed by intense inflammatory reactions that lasted for several weeks at the bite site. Bats and opossums were reported to inhabit the attic of the infested houses. In addition, a free-ranging opossum (Didelphis albiventris Lund) trapped in Rio Grande do Norte was found infested by argasid larvae. Based on morphological and/or molecular analysis, all ticks were identified as O. mimon. From one of the sites (Tiradentes, state of Minas Gerais), 20 field-collected nymphs were tested by a battery of polymerase chain reaction protocols targeting tick-borne microorganisms of the genera Babesia, Hepatozoon, Rickettsia, Borrelia, Anaplasma, Ehrlichia, and Coxiella; no tick specimen was found infected by any of these microorganism genera. The current study expands northwards the distribution of O. mimon, which has been shown to be very harmful to humans because of the intense inflammatory response that usually occurs after tick bites.

New tick records from the state of Rondônia, western Amazon, Brazil.

From 2005 to 2012, ticks were collected from different hosts at different localities of the state of Rondônia. The following 16 ixodid tick species were identified: Ixodes fuscipes, Amblyomma auricularium, Amblyomma coelebs, Amblyomma dubitatum, Amblyomma geayi, Amblyomma humerale, Amblyomma latepunctatum, Amblyomma longirostre, Amblyomma naponense, Amblyomma nodosum, Amblyomma oblongoguttatum, Amblyomma ovale, Amblyomma romitii, Amblyomma rotundatum, Amblyomma scalpturatum, and Amblyomma varium. From these, A. auricularium, A. dubitatum, and A. geayi are reported for the first time in the state of Rondônia. We provide the following tick-host associations that have not been reported anywhere: A. longirostre on Pteroglossus bitorquatus, A. rotundatum on Hydrodynastes gigas, and A. latepunctatum and A. scalpturatum on Hydrochoerus hydrochaeris. An adult male specimen of A. rotundatum is reported on Boa constrictor, comprising only the fourth male specimen to be recorded for this obligate parthenogenetic tick species. We also report the presence of the argasid species Ornithodoros kohlsi for the first time in Brazil, based on larval specimens collected on bats Molossops (Neoplatymops) mattogrossensis in Monte Negro, Rondônia. The present study increases the Brazilian tick fauna to 65 species, from which 34 species (52 %) are now registered to Rondônia. Such high diversity of ticks in a relatively small state, associated with increasing environmental alteration due to deforestation and human occupation, makes Rondônia a potential source of tick-borne diseases.

Amblyomma cajennense (Fabricius, 1787) (Acari: Ixodidae), the Cayenne tick: phylogeography and evidence for allopatric speciation.

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.

Description of the larva of Amblyomma calcaratum Neumann, 1899 (Acari: Ixodidae) by light and scanning electron microscopy.

The larval stage of Amblyomma calcaratum Neumann is described using optical and scanning electron microscopy. Unfed larvae were obtained from a colony of A. calcaratum originating from engorged females collected on Tamandua tetradactyla in the Jaraguá Mountain (23°40'S, 45°44'W), São Paulo County, Brazil. Eleven larvae were prepared and mounted on slides and observed under a light microscope equipped with a drawing tube. Three specimens were prepared for SEM. Several morphological characters are described, including the chaetotaxy of the idiosoma, palpi, and Haller's organ, as well as morphological features of the idiosoma, gnathosoma, and legs of A. calcaratum larvae. In addition, topographical and numerical patterns of integumentary structures on the larval idiosoma are described using a recently proposed nomenclature. On the idiosoma, setaes, lyrifissures, small glands, and large wax glands were found. These structures were observed isolated or associated over the entire idiosoma, except on the scutum, which lacks large wax glands. The topographical and numerical patterns of integumentary structures of the A. calcaratum larva showed only minor differences when compared with patterns of other Amblyomma larvae; however, a few key features can be used to differentiate A. calcaratum from other members of this genus.

Morphological description of the nymphal stage of Amblyomma geayi and new nymphal records of Amblyomma parkeri.

The external morphology of the nymph of Amblyomma geayi Neumann is described by optical and scanning electron microscopy. Unfed nymphs were obtained from an engorged A. geayi female, which had been collected on a sloth (Bradypus variegatus) from Belém municipality, State of Pará, northern Brazil, and was kept under laboratory conditions. With the present description, we propose a modification of a taxonomic key published in 2010 for the Amblyomma nymphs that occur in Brazil, through the inclusion of A. geayi. The nymph of A. geayi is morphologically very similar to the nymph of Amblyomma parkeri Fonseca and Aragão, with only slight morphological differences related to scutal surface and punctuations (more shagreened and less punctuated in A. geayi). These 2 nymphs differ from all other known Amblyomma nymphs from Brazil by the combination of auriculae present as small posterolateral rounded projections, eyes located at the level of the scutal midlength, and a rounded hypostome. These nymphal similarities as well the morphology of the adult stage corroborate previous studies that showed that A. geayi and A. parkeri are genetically closely related. Unpublished host records of the nymphs of both A. geayi and A. parkeri are provided. Established populations of A. geayi and A. parkeri seem to be geographically separated, since all confirmed records of A. geayi are from the northern half of South America (mainly the Amazonian region) and Central America, whereas all known records of A. parkeri are from the Atlantic rainforest biome in northeastern, southeastern, and southern Brazil.

Description of larva of Amblyomma romitii (Acari: Ixodidae) by optical and scanning electron microscopy, including porotaxy and phylogenetic analysis.

The description of the larva of Amblyomma romitii Tonelli-Rondelli is based on optical and scanning electron microscopy. Larvae were obtained under laboratory conditions from an engorged female collected on capybara from Rurópolis municipality, State of Pará, Northern Brazil. Several characters are presented including the chaetotaxy of idiosoma, palpi and Haller's organ. The larval porotaxy (topographical and numerical patterns of integumentary structures) was presented and compared to that of the other Amblyomma spp. larvae. The mitochondrial 16S rDNA partial sequence of A. romitii generated in the present study was aligned with sequences previously determined for other Amblyomma species available in Genbank and with some species presently sequenced. The larval morphology of A. romitii and other Neotropical Amblyomma spp. larvae is discussed as well as the DNA sequence and its phylogenetic position among other species of the genus.

Rickettsial infection in ticks (Acari: Ixodidae) collected on birds in southern Brazil.

The aim of the study was to evaluate rickettsial infection in ticks from wild birds of the Semidecidual and Atlantic Rainforest remnants of three municipalities of the State of Paraná, southern Brazil. Overall, 53 larvae and nymphs collected from birds were checked for the presence of Rickettsia DNA by molecular tests. Five tick species were tested: Amblyomma aureolatum (Pallas), Amblyomma calcaratum Neumann, Amblyomma longirostre (Koch), Amblyomma ovale Koch, and Amblyomma parkeri Fonseca and Aragão. A. longirostre ticks were infected with the spotted fever group agents Rickettsia amblyommii strain AL (32.3% infection rate) and Rickettsia parkeri strain NOD (5.9% infection rate). A new rickettsial genotype was detected in the tick A. parkeri (50% infection rate), which had never been reported to be infected by rickettsiae. Through phylogenetic analysis, this new genotype, here designated as strain ApPR, grouped in a cluster composed by different strains of Rickettsia africae, Rickettsia sibirica, and R. parkeri. We consider strain ApPR to be a new genotype of R. parkeri. This study reports for the first time rickettsial infection in ticks from birds in southern Brazil. The role of migrating birds in the dispersal of these rickettsial strains should be considered in ecological studies of spotted fever group agents in Brazil.

Ticks (Acari: Ixodidae) associated with small terrestrial mammals in the state of Minas Gerais, southeastern Brazil.

From June 2005 to November 2010, 43 small mammals encompassing 6 species of Didelphimorphia, 8 species of Rodentia, and 1 species of Lagomorpha were found parasitized by ticks in the state of Minas Gerais, southeastern Brazil. Nine tick species, in total 186 specimens, were identified as follows: Amblyomma cajennense (larvae and nymphs) on opossums and rodents; Amblyomma ovale (nymphs) on rodents; Amblyomma parvum (nymphs) on rodents; Amblyomma coelebs (nymphs) on opossums; Amblyomma dubitatum (nymph) on opossums; Ixodes amarali (females, nymphs, and larvae) on opossums and rodents; Ixodes loricatus (male, females, nymph) on opossums; Ixodes schulzei (female) on rodents; and Haemaphysalis leporispalustris (female) on rabbits. Most of the tick-host associations found in the present study have never been recorded in the literature; those include three new host records for I. amarali, four for A. cajennense, one for A. dubitatum, two for A. ovale, and one for A. coelebs. In addition, we provide the first record of A. coelebs in the state of Minas Gerais.

Description of a new species of bat-associated argasid tick (Acari: Argasidae) from Brazil.

A new species of argasid tick (Acari: Argasidae) is described from immature and adult specimens collected from several localities in Brazil. A complete morphological account is provided for all postembryonic life stages, i.e., larva, nymph, female, and male. Ornithodoros cavernicolous n. sp. is the 113(th) in the genus. Morphologically, the new species shares common features, e.g., presence of well-developed cheeks and legs with micromammillate cuticle, with other bat-associated argasid ticks included in the subgenus Alectorobius. In particular, the new species is morphologically related to Ornithodoros azteci Matheson, with which it forms a species group. Phylogenetic analysis based on the 16S rRNA gene sequences supports the placement of the new species within a large clade that includes other New World bat-associated argasids. However, the new species seems to represent an independent lineage within the genus Ornithodoros.