Two new species of Ornithodoros (Ixodida; Argasidae) from the Southern Cone of South America

Lyme Disease: A Review with Emphasis on Latin America

The spirochete Borrelia burgdorferi sensu lato (Lyme Group) is the causative agent of Lyme disease, transmitted to humans through tick bites carrying the bacteria. Common symptoms include fever, headache, fatigue, and the characteristic erythema migrans skin rash. If left untreated, the infection can affect joints, the cardiac system, and the nervous system. Diagnosis relies on symptoms, clinical signs (such as the rash), and potential exposure to infected ticks, with laboratory tests proving valuable when appropriately employed with validated methods. Most cases of Lyme disease respond effectively to a few weeks of antibiotic treatment. In Latin America, knowledge of Lyme disease is limited and often confounded, underscoring the significance of this review in aiding medical professionals in recognizing the disease. This study delves explicitly into Lyme disease in Argentina, neighboring countries, and other Latin American nations.

Laboratory life cycle of Ornithodoros puertoricensis (Ixodida: Argasidae) collected in the Colombian Caribbean

Three studies on the biology of Ornithodoros puertoricensis are available in the literature, using different hosts and incubation temperatures. In a previous study, we identified O. puertoricensis in the Colombian Caribbean. The aim of the present work was to analyze life cycle data along one generation from these specimens under laboratory conditions. Eggs of O. puertoricensis were collected in between fragments of bahareque material in a rural dwelling in the municipality of Planeta Rica (Córdoba Department, Colombia), and transported to the laboratory. All post-egg stages (i.e., larvae, nymphs, and adults) were incubated at 27 °C and 85% RH and fed on laboratory mice (Mus musculus). Sixteen engorged larvae were obtained to start a laboratory colony. Average feeding period for larvae was 4.6 days (4-5). The first nymphal instar (N1) did not require feeding and the subsequent nymphal stages (N2, N3, and N4) and adults had feeding periods ranging from 55 to 75 min. Average pre-molting period in nymphs was 15 days (10-21). Most of the N3 molted to males and all N4 molted to females. Two gonotrophic cycles were recorded: the first had a preoviposition period of 12 days (7-18) and produced 190 eggs (171-223), the second lasted 6.6 days (6-7) and produced 146 eggs (104-201). The mean life cycle duration (from parental eggs to F1 eggs) was 70.7 days (58.7-82.7) without fasting periods. The collected data agree with previous studies even with differences in hosts and maintenance conditions.

Ectoparasites of Didelphis virginiana From Yucatan, Mexico

A faunal study is presented to determine the species of ectoparasites found in the opossum Didelphis virginiana (Kerr) (Marsupialia: Didelphidae). For this, Tomahawk traps were placed in the peridomiciles of a rural town in Yucatán, to capture individuals of this marsupial and proceed to the collection of their ectoparasites. A total of 3,023 arthropods were collected from 145 opossums. The most frequent ectoparasites were the acarines Ornithodoros (Alectorobius) nr. talaje (64.8%) (Argasidae); Ornithonyssus wernecki Fonseca (53.8%) (Macronyssidae) and Didelphilicus serrifer Fain (25.5%) (Atopomelidae); the ticks Amblyomma parvum Aragão (8.3%) and A. mixtum Koch (10.3%) (Ixodidae); and the fleas Ctenocephalides felis (Bouché) (20.7%) and Pulex simulans Baker (8.3%) (Pulicidae). It is concluded that the ectoparasite fauna of this marsupial is mainly composed of euryxenous organisms, which have been documented as vectors of diseases caused by rickettsial bacteria. Since D. virginiana is widely adapted to the peridomiciliary environment in the region, this study allows recognizing those that represent a potential risk for the transmission of vector-borne zoonotic diseases.

New records and phylogenetic position of Ornithodoros knoxjonesi (Ixodida: Argasidae)

Larvae of Ornithodoros knoxjonesi collected at five localities in three countries were studied using morphological and molecular methods to confirm this species' taxonomic validity. The larva of O. knoxjonesi is characterized as having 14 pairs of dorsal setae, eight pairs of ventral setae, plus a posteromedian seta; an elongate dorsal plate, tapered anteriorly; and a hypostome that is narrower near its midlength, with posteriorly projecting denticles. Although the larvae of O. knoxjonesi and Ornithodoros peropteryx are morphologically quite similar, the larva of O. knoxjonesi is characterized as having dorsal setae that are wider at the tip than at the base, while in O. peropteryx these setae are narrower at the tip than at the base; moreover, the dorsal setae are shorter in O. knoxjonesi (Al 0.037-0.065; Pl 0.035-0.059) than in O. peropteryx (Al 0.120-0.132; Pl 0.080-0.096). These species also differ in that O. knoxjonesi possesses only the Al seta on tarsus I, whereas O. peropteryx has both Al and Pl setae. And while both species have two setae on coxae I-III, in O. knoxjonesi the anterior seta is tapering and smooth and the posterior is fringed, while both setae are fringed in O. peropteryx. At the molecular level, based on a maximum likelihood analysis using approximately 400 bp of the mitochondrial 16S rDNA gene, O. knoxjonesi appears as an independent lineage, separated from O. peropteryx by a genetic distance of 16.28 %. Balantiopteryx plicata is a common host of O. knoxjonesi; however, in this work we report Pteronotus personatus and Pteronotus gymnonotus as new hosts of this tick species.

Arthropods Associated with Mammals. Their Importance as Part of the Richness in a Biosphere Reserve in Mexico

The Chamela Biological Station (ChBS) is located in the Pacific Coast of Mexico in the State of Jalisco. This represents one of the core areas of the Chamela-Cuixmala Biosphere Reserve, characterized by one of the most threatened ecosystems, the tropical dry forest. Although accumulated knowledge of biological diversity, only few studies have been focused on ectoparasites or ectodytes associated with mammals, only 23 arthropod taxa had been recorded. In order to increase knowledge about arthropods associated with Mexican mammals, the objective of this work was to record the richness of arthropods (mites, ticks, lice, and fleas) associated with small and medium-sized mammals in the ChBS. A total of 81 hosts belonging to four orders, six families and nine species were captured. From these hosts, 4,946 arthropods were recovered: 4,007 mites, 673 ticks, 230 lice, and 36 fleas. Among medium-sized mammals, Nasua narica (L.) and Didelphis virginiana Kerr showed the highest levels of richness, with six arthropod taxa; among rodents, Heteromys pictus (Thomas) had the highest number of associated species (five). Within the 22 arthropod taxa registered in the present work, 12 represent new records for the reserve, and 3 represent new records for Mexico. With this study, the arthropod fauna associated with mammals in the ChBS has been raised to 38 taxa. In terms of biological conservation, knowledge of the species that inhabit natural reserves must be a priority, since this represents the baseline for species protected, not only in Mexico but around the world.

Description of a new soft tick species (Acari: Argasidae: Ornithodoros) parasite of Octodon degus (Rodentia: Octodontidae) in northern Chile

A new argasid (Argasidae) tick is herein described based on morphology and molecular data obtained from larvae parasitizing Octodon degus and from ticks collected inside burrows in northern Chile. Unfed laboratory-reared larvae were mounted in slides for morphometrical and morphological analyses. Larvae of Ornithodoros octodontus n. sp. share morphological traits with Ornithodoros quilinensis and Ornithodoros xerophylus, two species associated with rodents in the Argentinean Chaco. However, a longer hypostome with two rows of 21 and 22 denticles each one, and conspicuous leaf-shaped anal plates separate O. octodontus. While nymphal stages of O. octodontus lack cheeks and possess a micromammillated dorsal integument, adults have cheeks and exhibit markedly irregular mammillae along their dorsal surface. Phylogenetic analyses of neotropical Argasidae based on mitochondrial 16S rDNA sequences point that O. octodontus forms a monophyletic group with O. xerophylus and an unidentified Ornithodoros sp. from Bolivia, all of them associated with burrow-dweller rodents. Ornithodoros aragaoi and Ornithodoros davisi, two rare species collected once only in the Peruvian Andean Plateau during 1955 are morphologically closely related with adults and nymphs of O. octodontus. Biological observations of O. octodontus revealed autogenic females. For the moment, subgeneric classification of this new species depends on further biological studies. The fauna of ticks occurring in Chile is now represented by 22 species, 11 belonging to the Argasidae family.

Occurrence of autogeny in a population of Ornithodoros fonsecai (Acari: Argasidae)

Ornithodoros fonsecai is an argasid tick that is endemic to Brazil and has been described in the municipality of Bonito, state of Mato Grosso do Sul. Some specimens of this species were found in a cave in the municipality of Nobres, state of Mato Grosso. The specific identification of this population was confirmed by means of morphology and molecular biology. The mitochondrial 16S rDNA partial sequence of this species from Nobres has been deposited in GenBank (MK158949). The objective of this study was to elucidate the biology of O. fonsecai from Nobres, and to report autogeny in this tick population. Along three laboratory generations was observed molting of first nymphal instar to the second instar without feeding, a typical behavior of species included in the subgenus Alectorobius. The first generation (F1) presented five nymphal instars (N1 to N5), and most of adults emerged through molting of N5. The last nymphal instar of second generation (F2) was N4, but most of adults emerged from N3. In the third generation (F3) the last nymphal instar was N5, with most of the adults emerging from N4. In F2, some females (n = 20) originated from N3 began laying eggs without a blood meal. It was observed that those N3 fed twice before they molted to autogenic females. However, autogenic behavior occurred in relation to third generation females (F3) with specimens originating from N4 (n = 12) that were fed only once as nymphs. This behavior has already been reported as obligatory for the genera Otobius and Antricola, while it is facultative for one species of genus Argas and for four species of genus Ornithodoros. However, the present report provides the first record of facultative autogeny for a species of Ornithodoros in Brazil.

Ornithodoros (Ornithodoros) huajianensis sp. nov. (Acari, argasidae), a new tick species from the Mongolian marmot (Marmota bobak sibirica), Gansu province in China

A new argasid species, belonging to the subgenus Ornithodoros, namely, Ornithodoros (Ornithodoros) huajianensis was described for the first time based on the females, males and nymphs. The morphological features of each stage in the life cycle are unique, making identification easy, but are similar to other species of the subgenus Ornithodoros. The new species was diagnosed by the broad rectangular tongue and triangular tongue-shaped posterior lip in the male genital apron, a shallow camerostome with definite folds and smaller mammillae with single seta mixed with larger ones in nymph and adults. The new species had been collected from the Mongolian marmots Marmota bobak sibirica in Huajian village, Gulang county, Gansu province, China. Data on the phylogenic position, hosts and geographic distribution are also provided.

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A novel species of subgenus Ornithodoros is reported from a Mongolia marmot Marmota bobak sibirica in Gansu province, China.

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Ornithodoros (Ornithodoros) huajianensis n. sp. is described from females, males and nymphs.

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Partial sequence of 16S rDNA gene groups this species with O. moubata and O. compactus.

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Sequence divergence of new species from O. moubata 7.0% and from O. compactus.9.5%.

Anaplasmataceae, Borrelia and Hepatozoon agents in ticks (Acari: Argasidae, Ixodidae) from Chile

Microorganisms harbored by Chilean autochthonous ticks have been scarcely studied and current knowledge is restricted to three species of hard ticks only. The current study aimed to assess the presence of Anaplasmataceae, Borrelia and Hepatozoon agents in ticks collected directly from the environment, on reptiles, birds and mammals in twelve localities from northern, central and southern regions of the country and Antarctica. Ticks were identified by means of a morphological and molecular approach. PCR detections point the occurrence of an Anaplasma-like agent and a relapsing fever Borrelia sp. in Ornithodoros spheniscus; an Ehrlichia sp. and a Hepatozoon sp. in Ornithodoros atacamensis; "Candidatus Neoehrlichia chilensis", Borrelia burgdorferi sensu lato (s. l.), and Hepatozoon in Ixodes ticks morphologically related to the Ixodes sigelos group; and B. burgdorferi s. l. in Ixodes auritulus. Supported by phylogenetic analyses of characterized microorganisms, this study introduces putative vector roles and initial evidence on possible new agents detected in Chilean ticks.

Argasid and ixodid systematics: Implications for soft tick evolution and systematics, with a new argasid species list

The systematics of the genera and subgenera within the soft tick family Argasidae is not adequately resolved. Different classification schemes, reflecting diverse schools of scientific thought that elevated or downgraded groups to genera or subgenera, have been proposed. In the most recent classification scheme, Argas and Ornithodoros are paraphyletic and the placement of various subgenera remains uncertain because molecular data are lacking. Thus, reclassification of the Argasidae is required. This will enable an understanding of soft tick systematics within an evolutionary context. This study addressed that knowledge gap using mitochondrial genome and nuclear (18S and 28S ribosomal RNA) sequence data for representatives of the subgenera Alectorobius, Argas, Chiropterargas, Ogadenus, Ornamentum, Ornithodoros, Navis (subgen. nov.), Pavlovskyella, Persicargas, Proknekalia, Reticulinasus and Secretargas, from the Afrotropical, Nearctic and Palearctic regions. Hard tick species (Ixodidae) and a new representative of Nuttalliella namaqua (Nuttalliellidae), were also sequenced with a total of 83 whole mitochondrial genomes, 18S rRNA and 28S rRNA genes generated. The study confirmed the utility of next-generation sequencing to retrieve systematic markers. Paraphyly of Argas and Ornithodoros was resolved by systematic analysis and a new species list is proposed. This corresponds broadly with the morphological cladistic analysis of Klompen and Oliver (1993). Estimation of divergence times using molecular dating allowed dissection of phylogeographic patterns for argasid evolution. The discovery of cryptic species in the subgenera Chiropterargas, Ogadenus and Ornithodoros, suggests that cryptic speciation is common within the Argasidae. Cryptic speciation has implications for past biological studies of soft ticks. These are discussed in particular for the Ornithodoros (Ornithodoros) moubata and Ornithodoros (Ornithodoros) savignyi groups.

New records of Ornithodoros puertoricensis Fox 1947 (Ixodida: Argasidae) parasitizing humans in rural and urban dwellings, Panama

The presence of ticks inside human constructions was evaluated in two localities from Colon province (Charco La Piedra and Espinar) and one from Panama province (Ancon, City of Panama). In two of houses, eight people from Charco La Piedra and one from Ancón reported "insect bites," which produced blisters for several weeks. The investigation resulted in the collection of argasid ticks, which were identified by morphology and sequencing the 16s ribosomal RNA gene, and later evaluated for the presence of relapsing fever Borrelia DNA. All ticks were identified as Ornithodoros puertoricensis. While spirochetal DNA was not detected by PCR in the ticks, our report highlights the potential for relapsing fever borreliosis in rural and urban localities in Panama.

Ticks parasitizing bats (Mammalia: Chiroptera) in the Caatinga Biome, Brazil

In this paper, the authors report ticks parasitizing bats from the Serra das Almas Natural Reserve (RPPN) located in the municipality of Crateús, state of Ceará, in the semiarid Caatinga biome of northeastern Brazil. The study was carried out during nine nights in the dry season (July 2012) and 10 nights in the rainy season (February 2013). Only bats of the Phyllostomidae and Mormoopidae families were parasitized by ticks. The species Artibeus planirostris and Carolia perspicillata were the most parasitized. A total of 409 larvae were collected and classified into three genera: Antricola (n = 1), Nothoaspis (n = 1) and Ornithodoros (n = 407). Four species were morphologically identified as Nothoaspis amazoniensis, Ornithodoros cavernicolous, Ornithodoros fonsecai, Ornithodoros hasei, and Ornithodoros marinkellei. Ornithodoros hasei was the most common tick associated with bats in the current study. The present study expand the distributional ranges of at least three soft ticks into the Caatinga biome, and highlight an unexpected richness of argasid ticks inhabiting this arid ecosystem.

Ticks infesting bats (Mammalia: Chiroptera) in the Brazilian Pantanal

Ticks associated with bats have been poorly documented in the Neotropical Zoogeographical Region. In this study, a total of 1028 bats were sampled for tick infestations in the southern portion of the Brazilian Pantanal. A total of 368 ticks, morphologically identified as Ornithodoros hasei (n = 364) and O. mimon (n = 4), were collected from the following bat species: Artibeus planirostris, Platyrrhinus lineatus, Phyllostomus hastatus, Mimon crenulatum and Noctilio albiventris. Morphological identification of O. hasei was confirmed by molecular analysis. Regarding the most abundant bat species, only 40 (6.2%) out of 650 A. planirostris were infested by O. hasei, with a mean intensity of 7.2 ticks per infested bat, or a mean abundance of 0.44 ticks per sampled bat. Noteworthy, one single P. hastatus was infested by 55 O. hasei larvae, in contrast to the 2.5-7.2 range of mean intensity values for the whole study. As a complement to the present study, a total of 8 museum bat specimens (6 Noctilio albiventris and 2 N. leporinus), collected in the northern region of Pantanal, were examined for tick infestations. These bats contained 176 ticks, which were all morphologically identified as O. hasei larvae. Mean intensity of infestation was 22, with a range of 1-46 ticks per infested bat. Our results suggest that A. planirostris might play an important role in the natural life cycle of O. hasei in the Pantanal.

Morphological and molecular description of immature stages of Ornithodoros savignyi (Acari: Argasidae)

This study was designed to provide more details about larva, first nymph, and second nymph of Ornithodoros savignyi using a combination of light microscopy (LM), scanning electron microscopy (SEM), and partial sequence of mitochondrial 16S ribosomal ribonucleic acid (rRNA). The main characteristics of larva are wrinkled integument with many grooves, gnathosoma without camerostome cheeks, hypostome with a pair of large teeth apically, and tarsus without humps. The comparisons between the first and the second nymphs are different shape and distribution of dorsal grooves; a few spots without mammilla on the dorsal surface of the second nymph; 27 and 63-65 pairs of setae on the dorsal surface of the first and second nymphs, respectively; small holes on mammillae that are more dense in the second nymph; basis capitulum with two pairs of small setae in the second nymph; and one pair of sate in the first nymph, hypostome with dental formula 2/2 in the first nymph, and 3/3 in the second nymph. The partial 16S rRNA sequence of the second nymph that was determined as O. savignyi (450 bp) was deposited in GenBank under the accession number KU163242.