A third species of Nothoaspis Keirans & Clifford, 1975 (Acari: Argasidae): Nothoaspis setosus (Kohls, Clifford & Jones, 1969) n. comb.

In South America, early descriptions of soft tick species were based on examination of the external morphology of the larval stages. In many cases, specimens were collected only once as it is the case of some bat-associated Ornithodoros spp. If we are to understand the systematic scenario of South American soft ticks, these species become axial questions to be re-studied from a morphological and molecular point of view. The objective of this study was to assess the taxonomic identity of soft tick larvae collected on bats inhabiting crevices of a large rock in the Rondônia State (RO), Brazilian Amazon. After a detailed morphological analysis using light microscopy, three large engorged larvae sharing the same phenotype were identified as Ornithodoros setosus Kohls, Clifford & Jones, 1969, a species collected in 1964 on bats in RO. Remarkably, maximum parsimony and Bayesian phylogenetic analyses based on tick 16S rRNA mitochondrial gene sequences obtained from two of these specimens showed that O. setosus indeed corresponds to a species of Nothoaspis Keirans & Clifford, 1975. Therefore, a new combination, Nothoaspis setosus (Kohls, Clifford & Jones, 1969), is herein proposed. While an elongated triangular dorsal plate with a curvy-notched posterior margin, and bulges in the lateral margins of basis capitulum correspond to common characters in larvae of the genus Nothoaspis, polymorphic traits are represented by minute cornua in the basis of the capitulum, the dentition of the hypostomal tip, triangular spurs on coxae I, and the number of dorsal and circumanal setae.

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.

Ornithodoros peropteryx (Acari: Argasidae) in Bolivia: an argasid tick with a single nymphal stage.

By the end of the 1960s, the argasid tick Ornithodoros peropteryx was described from larval specimens collected from the bat Peropteryx macrotis in Colombia. Since its original description, no additional record of O. peropteryx has been reported, and its post-larval stages have remained unknown. During July 2010, 18 larvae were collected from 9 bats (Centronycteris maximiliani), resulting in a mean infestation of 2.0 ± 2.2 ticks per bat (range 1-8). These bats were captured in a farm in northeastern Bolivia close to Guaporé River in the border with Brazil. Morphological examinations of the larvae revealed them to represent the species O. peropteryx. One engorged larva that was kept alive in the laboratory moulted to a nymph after 9 days. Fourteen days after the larval moulting, the nymph moulted to an adult female without taking any blood meal during the nymphal period. This adult female was used for a morphological description of the female stage of O. peropteryx. In addition, the larvae were used for a morphological redescription of this stage. One larva and two legs extirpated from the adult female were submitted to DNA extraction and PCR targeting a fragment of the mitochondrial 16S rDNA gene, which yielded DNA sequences at least 11 % divergent from any available argasid sequence in Genbank. We show that O. peropteryx ontogeny is characterized by a single, non-feeding, nymphal stage. This condition has never been reported for ticks.

Ornithodoros guaporensis (Acari, Ixodida: Argasidae), a new tick species from the Guapore River Basin in the Bolivian Amazon.

The soft tick Ornithodoros guaporensis n. sp. (Acari: Ixodida: Argasidae) is described from larvae and adults. Morphological analysis and 16S rDNA sequences are provided. Adults were collected from a rocky fissure inhabited by bats located in the Amazonian forest in north-eastern Bolivia (Beni Department) close to the Guapord River. Larvae were obtained from eggs laid by females collected in the field, and which were fed on rabbits in the laboratory. Larvae of O. guaporensis are morphologically closely related to Ornithodoros rioplatensis, Ornithodoros puertoricensis and Ornithodoros talaje. Larvae of O. guaporensis and O. rioplatensis can be separated from O. puertoricensis and O. talaje by the number of pairs of dorsal setae (20 in O. guaporensis and O. rioplatensis, 18 in O. puertoricensis and 17 in O. talaje). Larvae of O. guaporensis and O. rioplatensis can be differentiated by the medial dental formula (2/2 in O. guaporensis and 3/3 in O. rioplatensis) and the apex of the hypostome, which is more pointed in O. rioplatensis than in O. guaporensis. The Principal Component Analysis performed with morphometric characters of larvae showed a clear separation among O. guaporensis, O. rioplatensis, O. puertoricensis and O. talaje. Significant morphological differences among adults of these four species were not found. The analysis of the 16S rDNA sequences allowed for the differentiation between O. guaporensis and the remaining Neotropical species of the family Argasidae.

New reports of Antricola guglielmonei and Antricola delacruzi in Brazil, and a description of a new argasid species (Acari).

Adults of 3 tick species (Acari: Argasidae) identified as Antricola guglielmonei, Antricola delacruzi, and Carios rondoniensis n. sp. were collected on bat guano in a cave in the state of Rondônia, western Amazon, Brazil. Adults of C. rondoniensis possess a unique combination of characters that distinguish them from all described adults in the Argasidae, i.e., a large spiracular plate densely filled with small goblets, a well-developed flap covering the female genital opening, and palpi containing several tufts of long setae on articles 2 and 3. Unlike Ornithodoros or other Carios species, adults of C. rondoniensis have a scooplike hypostome devoid of denticles, as in Antricola spp. Conversely, the presence of a pair of long posthypostomal setae, and a slitlike transverse fissure at the capsule opening of the Haller's organ, are characters of C. rondonensis that are also found in species of Carios and Ornithodoros, but not in Antricola species. Molecular analyses inferred from a portion of the 16S rRNA mitochondrial gene indicate that C. rondoniensis is phylogenetically closest to species of Carios, followed by species of Antricola, and then Ornithodoros. Because the highest bootstrap value linking C. rondoniensis to Carios spp. was 62%, further phylogenetic studies are needed to better evaluate the taxonomic status of the former species.

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.

Description of adults and nymph, and redescription of the larva, of Ornithodoros marinkellei (Acari:Argasidae), with data on its phylogenetic position.

The argasid tick Ornithodoros marinkellei Kohls, Clifford, and Jones, 1969 was described 4 decades ago based on larval specimens collected from bats (Pteronotus spp.) in Colombia and Panama. Thereafter, larval O. marinkellei parasitizing bats were reported from Venezuela, Guyana, and Brazil. Herein, we describe the adults and nymph, and redescribe the larva of O. marinkellei based on specimens recently collected in the western Brazilian Amazon region. In contrast to all other known adult argasids, the idiosoma of both males and females of O. marinkellei is covered with sclerotized plaques. The idiosoma of the nymph of O. marinkellei is entirely micromamillated, and differs from the adults by the absence of plaques. The larva of O. marinkellei is morphologically similar to the larvae of the 2 other species belonging to the subgenus Subparmatus , i.e., Ornithodoros viguerasi Cooley and Kohls, 1941 and Ornithodoros mormoops Kohls, Clifford, and Jones, 1969 . Because of the long and narrow dorsal plate, the larva of O. marinkellei is readily distinguished from O. viguerasi and O. mormoops. Comparison of our larvae from Brazil with O. marinkellei paratype specimens from Colombia confirmed their taxonomic identification. However, a few morphological differences, particularly in the size of the gnathosoma, were observed. Further studies are necessary to clarify whether O. marinkellei is a complex of different species, or a single species represented by morphologically polymorphic, and geographically distinct populations. Partial mitochondrial 16S rDNA gene sequences were generated for O. marinkellei specimens from Brazil, and compared with available homologous sequences in GenBank. Phylogenetic analyses revealed O. marinkellei to be distinct from the remaining argasid species available in GenBank, including other bat-associated tick species that are found in sympatry with O. marinkellei in the Neotropical region.

Comparison of two methods for collecting free-living ticks in the Amazonian forest.

In the present study, we compared 2 methods for collecting ixodid ticks on the verges of animal trails in a primary Amazon forest area in northern Brazil. (i) Dragging: This method was based on passing a 1-m(2) white flannel over the vegetation and checking the flannel for the presence of caught ticks every 5-10 m. (ii) Visual search: This method consisted of looking for questing ticks on the tips of leaves of the vegetation bordering animal trails in the forest. A total of 103 adult ticks belonging to 4 Amblyomma species were collected by the visual search method on 5 collecting dates, while only 44 adult ticks belonging to 3 Amblyomma species were collected by dragging on 5 other collecting dates. These values were statistically different (Mann-Whitney Test, P=0.0472). On the other hand, dragging was more efficient for subadult ticks, since no larva or nymph was collected by visual search, whereas 18 nymphs and 7 larvae were collected by dragging. The visual search method proved to be suitable for collecting adult ticks in the Amazon forest; however, field studies should include a second method, such as dragging in order to maximize the collection of subadult ticks. Indeed, these 2 methods can be performed by a single investigator at the same time, while he/she walks on an animal trail in the forest.

Description of a new argasid tick (Acari: Ixodida) from bat caves in Brazilian Amazon.

Nothoaspis amazoniensis n. sp. (Acari: Ixodida: Argasidae) is described from adult and immature ticks (nymph II, nymph I, larva) collected from bat caves in the Brazilian Amazon. Also, 16S rDNA sequences are provided. The diagnostic characters for adults are the presence of false shield or nothoaspis, an anteriorly projecting hood covering the capitulum, a medial extension of palpal article I (flaps), genital plate extending from coxa I to IV, absence of 2 setae on the internal margin of the flaps, a minute hypostome without denticles, presence of a central pore in the base of hypostome, and a reticulate surface pattern on the posterior half of the nothoaspis in males. The nymph II stage is characterized by a hood that is small in relation to the capitulum, short coxal setae, palpal flaps lacking setae on the internal margin, long hypostome, pointed with dentition 4/4 apically, and the anterior half of the body is covered by a cell-like configuration. Nymph I stage is characterized by a hood, small in relation to the capitulum, dorsum of the body covered by a cell-like configuration, venter integument covered by a cell-like configuration, and hypostome dentition 4/4 with apices that are "V"-shaped. Diagnostic characters of the larvae are the number and size of dorsal setae, and the shape of scutum and hypostome. The new species appears to have a life cycle with a larva that feeds on bats, a non-feeding nymphal stage (nymph I), a feeding nymphal stage (nymph II), and adults that probably represent non-feeding stages.