New records of soft ticks (Acari: Argasidae) from caves in Brazil, with a morphological study of Ornithodoros fonsecai and an analysis of the taxonomic status of Antricola inexpectata.

In this study, we report soft ticks from bat-inhabiting caves in different areas of Brazil. From 2010 to 2019, we collected 807 tick specimens from nine caves located in four Brazilian states among two biomes. Ticks were morphologically identified as Antricola guglielmonei (282 specimens), Ornithodoros cavernicolous (260 specimens), and Ornithodoros fonsecai (265 specimens). Whereas A. guglielmonei was collected on bat guano in hot caves, O. cavernicolous and O. fonsecai were collected in cracks and crevices on the walls of cold caves, sometimes in the same chamber. Morphological identifications were corroborated by molecular and phylogenetic analyses inferred from tick mitochondrial 16S rRNA gene partial sequences. The sequences of A. guglielmonei, O. cavernicolous and O. fonsecai collected in this study clustered with conspecific GenBank sequences from different localities of Brazil. Remarkably, a clade containing 12 sequences of O. fonsecai was clearly bifurcated, denoting a degree of genetic divergence (up to 5 %) of specimens from Cerrado/Atlantic Forest biomes with the specimens from the Caatinga biome. To further evaluate this divergence, we performed morphometric analysis of the larval stage of different O. fonsencai populations by principal component analysis, which indicated that the larvae from Caatinga populations were generally smaller than the larvae from other biomes. Some of the present A. guglielmonei specimens were collected from the type locality of Antricola inexpectata. Comparisons of these specimens with the type specimens of A. inexpectata and A. guglielmonei indicated that they could not be separated by their external morphology. Hence, we are relegating A. inexpectata to a synonym of A. guglielmonei. This proposal is corroborated by our phylogenetic analysis.

Molecular detection of Borrelia sp. in Ornithodoros cavernicolous (Acari: Argasidae) in midwestern Brazil.

Ticks are obligate hematophagous parasites that can transmit to vertebrate hosts several pathogens, including viruses, bacteria, protozoa and helminths. Among these agents, some Borrelia species some Borrelia species cause disease in humans and other vertebrate hosts; therefore, they have medical and veterinary health importance. To gather additional information on Borrelia species in Brazil, the current study aimed to detect the presence of these species in Ornithodoros cavernicolous ticks collected in September 2019 from cement pipes that are used by bats as shelter in a farm located in the midwestern region of Brazil. DNA samples obtained from 18 specimens of O. cavernicolous were subjected of two polymerase chain reactions, targeting a segment of the Borrelia fla B gene. Of the samples tested, only one (6 %, 1/18) showed amplification. The nucleotide sequence of the amplified DNA showed more than 97 % (293/300) identity with a sequence of a Borrelia sp. detected in blood collected from a bat from Macaregua Cave, Colombia, and more than 97 % (292/300) detected in lungs from vampire bats from northeastern Brazil. The deduced amino acid sequences were identical to each other. Phylogenetic analysis indicated that these sequences formed a group of Borrelia species (putatively associated with bats) that is closely related to sequences of Borrelia species of the Lyme borreliosis group. Further investigations should be carried out in order to determine whether the sequence of the Borrelia sp. we found belongs to a new taxon. It will also be of great importance to determine which vertebrate hosts, besides bats, O. cavernicolous ticks can parasitize in order to investigate whether the Borrelia sp. we found may be transmitted and cause disease to the other vertebrate hosts.

Morphological and molecular confirmation of Ornithodoros hasei (Schulze, 1935) (Acari: Argasidae) in Colombia.

A large number of tick species are proven vectors for the transmission of bacteria, protozoa, and viruses. Soft ticks (Acari: Argasidae) in South America have been found to be the most frequent carriers of borreliae of the relapsing fever group (RFG); however, there are several information gaps specially on the taxonomy and distribution of some tick species. Here, we used light microscopy, scanning electron microscopy, and PCR amplification of a fragment of the mitochondrial 16S rRNA gene to evaluate 174 larvae of Ornithodoros (Argasidae) collected from three bat species (Eptesicus orinocensis, Molossus rufus and Noctilio albiventris) in the Orinoquia Region of Colombia. The morphological and molecular results confirmed that all the analyzed larvae corresponded to Ornithodoros hasei. Comparisons of mitochondrial 16S rDNA sequences showed low genetic divergence (0% - 0.3%) between larvae of the Department of Arauca in the Orinoquia Region and higher genetic divergence (3.4 - 4.7%) in sequences from other American countries. Our work represents the most recent collection of this species in Colombia and provides a molecular evaluation for the first time. Moreover, a new association of O. hasei with bats such as E. orinocensis is documented. Considering the wide distribution of O. hasei in the American Continent, and its putative role as vector for Borrelia, integrative studies that involve morphological, morphometric, molecular data and experimental crosses are needed to determine if the higher genetic distances are associated with cryptic speciation, as detected in other tick complexes, or represent genetic divergences among geographically different populations of O. hasei.

Multivariate discrimination among cryptic mites of the genus Androlaelaps (Acari: Mesostigmata: Laelapidae) parasitic of sympatric akodontine rodents (Cricetidae: Sigmodontinae) in northeastern Argentina: possible evidence of host switch followed by speciation, with the description of two new species.

Laelapids are among the most common ectoparasites of rodents. Currently, it is under discussion whether there is a single polixenous species that parasites a variety of hosts, or whether there are cryptic species highly host specific. Herein, multivariate morphometric analyses of cryptic sympatric laelapids of the genus Androlaelaps allowed us to identify different species. These species are specific of their akodontine hosts, Akodon montensis and Thaptomys nigrita, in localities situated in northeastern Argentina. In addition, we analyzed similar laelapids associated with the akodontines Deltamys kempi and Akodon cursor. Using principle component analyses we differentiated four laelapid species, each one host specific, independent of sympatry of the hosts, and without geographical variation. From these four species, we described two new species (Androlaelaps navonae n. sp. and Androlaelaps wingei n. sp.). We determined the four species based on a range of variations in several characters, mainly size. These four laelapid species belong to the Androlaelaps rotundus species group, specific to akodontines. These species are very similar among them but differ from the remainder species of the group by their small size, distance between j6 setae similar to the distance between the z5 setae, strong ventral setae, opisthogaster with 13 pairs of strong setae (one close to the distal margin of epigynal shield), and anal shield wider than long. Further studies will elucidate whether they constitute a new laelapid genus. Phylogenetic and ecological factors influencing host-specificity are discussed, and we propose that host colonization could have taken place by host switching of a single laelapid species among rodent species, followed by speciation.

Ticks (Acari: Ixodidae) infesting wild birds in the eastern Amazon, northern Brazil, with notes on rickettsial infection in ticks.

The aim of the study was to report tick infestations on wild birds in a region of the eastern Brazilian Amazon and evaluate the rickettsial infection of these ticks. Wild birds captured by mist nets were examined for the presence of ticks, which were collected and identified to species by morphology or molecular methods. In addition, part of these ticks was individually tested by polymerase chain reaction targeting portions of the rickettsial genes gltA and ompA. Among 331 captured birds, representing 56 species, 133 individuals (40.2%) from 34 species were found infested by 443 ticks, being Amblyomma longirostre (Koch) the most common (103 larvae, 12 nymphs), followed by Amblyomma humerale Koch (15 larvae, 3 nymphs), Amblyomma geayi Neumann (seven larvae, one nymph), Amblyomma calcaratum Neumann (one larva, four nymphs), Amblyomma coelebs Neumann (two larvae), and Haemaphysalis juxtakochi Cooley (one larva, two nymphs). Other 285 larvae and 7 nymphs collected from birds could not be identified to species and were morphologically identified as Amblyomma spp. The species A. humerale and A. geayi are recorded for first time parasitizing birds in the Neotropical region. Among 67 A. longirostre and 7 A. geayi, 38 (56.7%) and 4 (57.1%), respectively, were found infected by Rickettsia amblyommii. In spite of R. amblyommii being not currently recognized as human or animal pathogen, there has been serological evidence for human and canine infection by this agent in the USA and in the Brazilian western Amazon.

Genetic similarity among Agistemus pallinii Matioli et al (Acari: Stigmaeidae) found in citrus orchards in Viçosa, Minas Gerais State, Brazil.

Stigmaeidae are very important predators of mite and insect pests on several crops in Brazil. It is considered the second most important family of predatory mites in citrus orchards in Brazil. However, their identification, especially that of the members of the genus Agistemus, is rather difficult based only on morphology. Hence, this study describes the use of random amplified polymorphic DNA (RAPD-PCR) markers to determine the genetic similarity of an Agistemus pallinii Matioli et al population found in 2004 in a citrus orchard in Viçosa, Minas Gerais State, Brazil, preying on Panonychus citri (McGregor). Amplifi cations were performed with 12 random primers (OPAA8, OPAA19, OPAB1, OPAB5, OPAB18, OPAC9, OPAC17, OPAC19, OPAD10, OPAE9, OPAE12 and OPAE17), which generated 119 bands, with 53.8% polymorphism. The coefficients of genetic similarity among the individuals ranged from 0.68 to 0.99, indicating a high genetic similarity among them. The 3D projection analysis clustered the majority of individuals confirming their high similarity. Though individuals of A. pallinii are minute (+/- 360 microm long), the PCR-RAPD technique can still be used for their identification, complementing morphological analyses or for comparison of populations collected in different geographic regions. This is the first molecular study carried out with stigmaeid mites.

Genetic similarity among Agistemus pallinii Matioli et al (Acari: Stigmaeidae) found in citrus orchards in Viçosa, Minas Gerais State, Brazil / Similaridade genética entre Agistemus pallinii Matioli et al (Acari: Stigmaeidae) encontrados em pomares de citros em Viçosa, MG

Stigmaeidae are very important predators of mite and insect pests on several crops in Brazil. It is considered the second most important family of predatory mites in citrus orchards in Brazil. However, their identification, especially that of the members of the genus Agistemus, is rather difficult based only on morphology. Hence, this study describes the use of random amplified polymorphic DNA (RAPD-PCR) markers to determine the genetic similarity of an Agistemus pallinii Matioli et al population found in 2004 in a citrus orchard in Viçosa, Minas Gerais State, Brazil, preying on Panonychus citri (McGregor). Amplifi cations were performed with 12 random primers (OPAA8, OPAA19, OPAB1, OPAB5, OPAB18, OPAC9, OPAC17, OPAC19, OPAD10, OPAE9, OPAE12 and OPAE17), which generated 119 bands, with 53.8 percent polymorphism. The coefficients of genetic similarity among the individuals ranged from 0.68 to 0.99, indicating a high genetic similarity among them. The 3D projection analysis clustered the majority of individuals confirming their high similarity. Though individuals of A. pallinii are minute (± 360 µm long), the PCR-RAPD technique can still be used for their identification, complementing morphological analyses or for comparison of populations collected in different geographic regions. This is the first molecular study carried out with stigmaeid mites.

Stigmaeidae são importantes predadores de ácaros e insetos pragas em várias culturas no Brasil. Essa família é considerada a segunda mais importante de ácaros predadores em citros no Brasil. Entretanto, o status taxonômico desses ácaros, principalmente do gênero Agistemus, é difícil de ser analisado com base em caracteres morfológicos. Assim, este trabalho descreve o uso de marcadores polimórfi cos amplificados ao acaso (PCR-RAPD) para investigar a similaridade genética de uma população de Agistemus pallinii Matioli et al encontrada em 2004 em pomar de citros em Viçosa, MG, predando Panonychus citri (McGregor). As amplificações foram realizadas com 12 iniciadores randômicos (OPAA8, OPAA19, OPAB1, OPAB5, OPAB18, OPAC9, OPAC17, OPAC19, OPAD10, OPAE9, OPAE12 e OPAE17), os quais geraram 119 bandas, sendo 53,8 por cento polimórficas. Os coeficientes de similaridade genética entre os indivíduos variaram de 0,68 a 0,99, indicando alta similaridade entre eles. A análise de projeção gráfica 3D mostrou que a maioria dos indivíduos analisados formou um único grupo, confirmando a alta similaridade genética entre os mesmos. Assim, mesmo considerando o pequeno tamanho de A. pallinii (± 360 µm), a técnica de PCR-RAPD pode ser utilizada para a sua identificação, em suporte às análises morfológicas ou em comparações de populações coletadas em diferentes regiões geográficas. O presente trabalho representa o primeiro estudo molecular realizado com ácaros da família Stigmaeidae.