Revisão do gênero Amblyomma Koch, 1844 (Acari: Ixodidae) no Brasil

Abstract

Fifty nine tick species of the genus Amblyomma are known to occur in the Neotropical region. Of these, 47 species are exclusively Neotropical, 11 occur in the Nearctic region as well and only one is not endemic to the Americas. To date, 33 species were described from Brazil, of which only two are endemic. The genus presents a wide range of hosts, including most orders of mammals. Birds are frequently infested by the immature forms of some species. Amphibians and reptiles are also among the genus' hosts. In order to revise the genus Amblyomma in Brazil, the present study was divided into two chapters. The first includes the diagnosis of each species as well as an identification key, based on electron micrographs. The second chapter presents new information on the genus Amblyomma, including data on geographic distribution and hosts for each species. A few type specimens, deposited in Brazilian and foreign institutions were examined as well as material deposited in the main Brazilian collections. The data obtained was compared to that available in literature. Of those species for which DNA sequencing was carried out, A. auricularium and A. pseudoconcolor showed 98.3% identity between them. However, the latter species showed 88.8% similarity with A. pseudoconcolor deposited in GenBank. Thus, it is necessary to repeat the analyses using a larger number of ticks from different localities and until further studies are carried out A. auricularium and A. pseudoconcolor should be treated as separate species. The taxonomic status of A. nodosum and A. calcaratum as two distinct taxa was confirmed, since the identity between sequences was 89%. Similarly, the sequences of A. parkeri and A. longirostre were different, with 87% similarity confirming the validity of both species. Based on morphological characters and on molecular biology A. parkeri was separated from A. longirostre and A. geayi and its validity confirmed. The distribution range of A. auricularium was expanded, including the states of Tocantins, Piauí and Mato Grosso. The presence of A. cajennense was confirmed for Amazonas and Amapá was cited as a new record for this species. Amblyomma coelebs and A. dissimile were recorded for the first time from Roraima, A. dubitatum from Amazonas and A. naponense from Acre, Bahia, Tocantins and Espírito Santo. The states of Roraima and Amazonas were included in the distribution range of A. oblongoguttatum, and Paraná and Roraima in the distribution range of A. scalptutarum. The occurrence of A. ovale was confirmed from the state of Acre and A. triste from Mato Grosso do Sul. After many years, A. parkeri was again recorded from Brazil and it's distribution range expanded to the states of Rio de Janeiro and Paraná. The states of Espírito Santo, Sergipe and Tocantins were considered new locality records for A. rotundatum. The record of A. dissimile from Rio Grande do Sul was not considered since the host was already infested when it reached the state. The record of A. humerale from São Paulo was also not considered since the specimen was actually A. rotundatum. The occurrence of A. geayi in the state of Paraná was considered doubtful.