Valeria C. Onofrio

Nymphs of the genus Amblyomma (Acari: Ixodidae) of Brazil: descriptions, redescriptions, and identification key.

Together with the larval stage, the nymphal stage of ticks of the genus Amblyomma are the most aggressive ticks for humans entering areas inhabited by wildlife and some domestic animals in Brazil. However, due to the absence of morphological descriptions of the nymphal stage of most Brazilian Amblyomma species, plus the lack of an identification key, little or nothing is known about the life history of Amblyomma spp. nymphs in the country. In the present study, morphological description of the nymphal stage, illustrating important external characters through scanning electron microscopy, is provided for nymphs of 15 Amblyomma species that occur in Brazil, for which the nymphal stage had never been described: A. aureolatum, A. auricularium, A. calcaratum, A. coelebs, A. fuscum, A. humerale, A. incisum, A. latepunctatum, A. naponense, A. nodosum, A. ovale, A. pacae, A. pseudoconcolor, A. scalpturatum, A. varium. In addition, the nymphal stage of 12 Amblyomma species, which had been previously described, are redescribed: A. brasiliense, A. cajennense, A. dissimile, A. dubitatum, A. longirostre, A. oblongoguttatum, A. parkeri, A. parvum, A. romitii, A. rotundatum, A. tigrinum, A. triste. The descriptions and redescriptions totalized 27 species. Only 2 species (A. geayi, A. goeldii) out of the 29 Amblyomma species established in Brazil are not included in the present study. A dichotomous identification key is included to support taxonomic identification of the nymphal stage of 27 Amblyomma species established in Brazil.

The ticks (Acari: Ixodida: Argasidae, Ixodidae) of Brazil

Abstract The tick species found in Brazil are reviewed. Today, 61 species belonging to nine genera (Argas (1 sp.), Antricola (3 spp.), Carios (10 spp.), Ornithodoros (3 spp.), Amblyomma (30 spp.), Dermacentor (1 sp.), Haemaphysalis (3 spp.), Ixodes (8 spp.), and Rhipicephalus (2 spp.)) are regarded as endemic or established in Brazil. The presence of 11 species (Amblyomma albopictum, Amblyomma fulvum, Amblyomma hirtum, Amblyomma multipunctum, Amblyomma pseudoparvum, Amblyomma scutatum, Aponomma omissum, Argas persicus, Carios puertoricensis, Ixodes pararicinus, and Rhipicephalus turanicus) is doubtful or requires confirmation. Reports of nine species (Amblyomma americanum, Amblyomma extraoculatum, Amblyomma imitator, Amblyomma maculatum, Dermacentor andersoni, Ixodes affinis, Ixodes cooleyi, Ixodes ricinus, and Rhipicephalus annulatus) are regarded as erroneous due to misidentifications or misleading information. Ten species (Amblyomma argentinae, Amblyomma darwini, Amblyomma parvitarsum, Bothriocroton undatum, Hyalomma aegyptium, Hyalomma dromedarii, Hyalomma marginatum, Otobius megnini, Rhipicephalus bursa, and Rhipicephalus evertsi) are exotic ticks that have probably failed to establish themselves in this country. Eight species (Amblyomma denticulatum, Ixodes imperfectus, Ixodes flavidus, Ixodes maloni, Ixodes perpunctatus, Ixodes pygmaeus, Ixodes serrafreirei, and Ixodes variolatus) are regarded as invalid because of inadequate descriptions. Finally, over 60 tick names cited as part of the Brazilian fauna are actually misspellings, misapplied names, or species that have fallen into synonymy.

Catalogue of the tick collection (Acari, Ixodida) of the Museu de História Natural Capão da Imbuia, Curitiba, Paraná, Brazil

The tick collection of the Museu de Historia Natural Capao da Imbuia was first sorted in the end of the 80s, and a list of specimens was published in 1992. During the last ten years, the collection has grown substantially and became the depository collection for type-specimens. The collection is the most regional representative depository of ticks from the State of Parana, and it is one of the four largest Brazilian collections in number of specimens. All material was revised, and the data were computerized and catalogued in cards. To date, the collection includes 504 vials, with 2,073 specimens, belonging to 25 species and six genera of the families Argasidae and Ixodidae. The ticks were collected in regional and state parks and in green areas from 60 municipalities distributed within eight Brazilian states. This catalogue corrects some of the records published in 1992 for the state of Parana and records new host species for Amblyomma aureolatum (Pallas, 1772), A. cajennense (Fabricius, 1787), A. longirostre (Koch, 1844), A. tigrinum Koch, 1844, Ixodes aragaoi Fonseca, 1935, I. auritulus Neumann, 1904, I. fuscipes Koch, 1844 and I. paranaensis Barros-Battesti, Arzua, Pichorim & Keirans, 2003. Amblyomma brasiliense Aragao, 1908, A. coelebs Neumann, 1899, A. nodosum Neumann, 1899 and I. fuscipes are recorded, for the first time, from the state of Parana; A. longirostre from Rio Grande do Sul; I. fuscipes from Santa Catarina; I. schulzei Aragao & Fonseca, 1951 from Rondonia; and A. rotundatum Koch, 1844 from Bahia. In addition Haemaphysalis juxtakochi Cooley, 1946 and I. fuscipes are recorded for the first time, infesting birds.

Description of a New Species of Bat-Associated Argasid Tick (Acari: Argasidae) from Brazil

abstract:  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 113th 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.

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.

Redescription of the female, description of the male, and several new records of Amblyomma parkeri (Acari: Ixodidae), a South American tick species

The tick Amblyomma parkeri Fonseca and Aragão was described in 1952, based on female and immature ticks collected in the states of São Paulo and Santa Catarina, Brazil. Thereafter, there has been no further report of A. parkeri, and the male has remained unknown. Herein, we examined ticks collected on porcupines from a locality in the state of São Paulo. Some of the ticks were identified as Amblyomma longirostre (Koch, 1844), whereas others as A. parkeri, including male specimens, for which we provide the first description. We also provide additional reports of A. parkeri after examining collections of A. longirostre and Amblyomma geayi Neumann, 1899 from different tick collections. Morphological evidence to support the original description of A. parkeri is presented, supported by molecular analyses of portions of the 16S rRNA and 12S rRNA mitochondrial genes. Morphological particularities to separate A. parkeri, A. longirostre, and A. geayi are provided.

Redescription of larva, nymph and adults of Ixodes (I.) loricatus Neumann, 1899 (Acari: Ixodidae) based on light and scanning electron microscopy

Ticks of the genus Ixodes are poorly known in the Neotropical zoogeographical region, from where only 45 species have been recorded. In Brazil, the genus is currently represented by eight species, four of which are known only from this country. This paper presents a redescription of all active stages in the life-cycle of I. loricatus, based on optical and scanning electron microscopy. In addition, the relationship of I. loricatus to other Neotropical Ixodes is presented and discussed.

Diagnoses of and illustrated key to the species of Ixodes Latreille, 1795 (Acari: Ixodidae) from Brazil

The current Brazilian Ixodes fauna is composed of the following eight species: I. amarali Fonseca, 1935; I. aragaoi Fonseca, 1935; I. auritulus Neumann, 1904; I. fuscipes Koch, 1844; I. loricatus Neumann, 1899; I. luciae Sénevet, 1940; I. paranaensis Barros-Battesti, Arzua, Pichorim & Keirans, 2003; and I. schulzei Aragão & Fonseca, 1951. Further studies are needed to establish the taxonomic status of I. serrafreirei Amorim, Gazeta, Bossi & Linhares, 2003, a recently proposed species based solely on the nymphal stage. We present an up-to-date key to adults of the currently valid Brazilian species of Ixodes based on scanning electron microscopy. The relationships between Brazilian and other Neotropical Ixodes are also discussed.

Ornithodoros faccinii n. sp. (Acari: Ixodida: Argasidae) parasitizing the frog Thoropa miliaris (Amphibia: Anura: Cycloramphidae) in Brazil

BackgroundMost argasid ticks from the Neotropical region are parasites of mammals and birds, with a few records from reptiles. Many species of the genus Ornithodoros are known only through larval descriptions, and their chaetotaxy and morphological characteristics have been used to separate the taxa. In the present study, we describe the larva and the nymph of first instar of a new species of the genus Ornithodoros that was collected from frogs of the species Thoropa miliaris.MethodsLarvae of Ornithodoros were collected from frogs of the species T. miliaris at waterfalls in the state of Rio de Janeiro, southeastern Brazil. The larval and nymphal description was based on optical and scanning electron microscopy. Molecular analysis using the argasid 16S rRNA sequences available in GenBank was also conducted.ResultsOrnithodoros faccinii sp. n. is closely related to Ornithodoros clarki Jones & Clifford, Ornithodoros marinkellei Kohls, Clifford & Jones, Ornithodoros capensis Neumann and Ornithodoros sawaii Kitaoka & Susuki. However, the larval morphology of the new species is unique. The mitochondrial 16S rDNA partial sequence of O. faccinii generated in the present study was deposited in GenBank under the number KP861242.ConclusionsThe larvae collected from Thoropa miliaris are a new species, Ornithodoros faccinii n. sp. This is the first report of argasid ticks on frogs in Brazil, the second on frogs and the third on Amphibia in the Neotropical region.

Ixodes (Ixodes) pararicinus Keirans & Clifford, 1985 (Acari: Ixodidae): description of the immature stages, distribution, hosts and medical/veterinary importance.

The immature stages of the Neotropical tick Ixodes (Ixodes) pararicinus Keirans & Clifford, 1985 are described from specimens in a laboratory colony initiated from engorged females collected on cattle and larvae fed on mice and chickens. The larva and nymph of I. pararicinus are described using SEM micrographs as well as drawings for some features of the larva. Additionally, immature stages of I. pararicinus collected on wild mice and birds in Uruguay and Argentina were compared with specimens from the laboratory colony. A taxonomic key to the nymphs of the species of the ricinus complex established in the Western Hemisphere is presented. The distribution of I. pararicinus comprises Argentina, Colombia and Uruguay, but it is also probably established in Bolivia, Brazil, Chile and Peru. Most adult ticks of this species have been found on introduced domestic artiodactyles, although Neotropical deer species must have been the ancestral host. Larvae and nymphs of I. pararicinus have also been found on sigmodontine rodents and passeriform birds. Although I. pararicinus is a member of the ricinus complex, which contains the main vectors of Borrelia burgdorferi (sensu lato), there are few studies concerning its potential for pathogen transmission.