title: Geographical distribution of Amblyomma cajennense (sensu lato) ticks (Parasitiformes: Ixodidae) in Brazil, with description of the nymph of A. cajennense (sensu stricto).
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, 05508-270, Brazil.
authors.forename: Thiago F
authors.initials: TF
authors.lastname: Martins
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, 05508-270, Brazil.
authors.forename: Amália R M
authors.initials: AR
authors.lastname: Barbieri
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, 05508-270, Brazil.
authors.forename: Francisco B
authors.initials: FB
authors.lastname: Costa
authors.affiliation: Faculdade São Lucas, R. Alexandre Guimarães Areal 1927, Porto Velho, Rondônia, 78916-450, Brazil.
authors.forename: Flávio A
authors.initials: FA
authors.lastname: Terassini
authors.affiliation: Faculdade São Lucas, R. Alexandre Guimarães Areal 1927, Porto Velho, Rondônia, 78916-450, Brazil.|Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Professor Lineu Prestes 1374, São Paulo, 05389-970, Brazil.
authors.forename: Luís M A
authors.initials: LM
authors.lastname: Camargo
authors.affiliation: Coordenação Geral do Programa Nacional de Controle da Malária, Setor Comercial Sul, Quadra 04, Bloco A, Edifício Principal, 6° Andar, Brasília, Distrito Federal, 70304-000, Brazil.
authors.forename: Cássio R L
authors.initials: CR
authors.lastname: Peterka
authors.affiliation: Departamento de Ciências Básicas e Produção Animal, Faculdade de Agronomia, Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso, Av. Fernando Corrêa da Costa 2367, Cuiabá, Mato Grosso, 78060-900, Brazil.
authors.forename: Richard
authors.initials: R
authors.lastname: de C Pacheco
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, 05508-270, Brazil.
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Dias
authors.affiliation: Instituto Latino-Americano de Ciências da Vida e da Natureza, Universidade Federal da Integração Latino-Americana, Av. Tarquínio Joslin dos Santos 1000, Foz do Iguaçu, Paraná, 85870-901, Brazil.
authors.forename: Pablo H
authors.initials: PH
authors.lastname: Nunes
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, 05508-270, Brazil.|Universidade de Santo Amaro, R. Prof. Enéas de Siqueira Neto 340, São Paulo, 04829-300, Brazil.
authors.forename: Arlei
authors.initials: A
authors.lastname: Marcili
authors.affiliation: Curso de Medicina Veterinária, Faculdade de Medicina Veterinária, Universidade Federal do Pará, Av. Maximino Porpino 1000, Castanhal, Pará, 68740-000, Brazil.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Scofield
authors.affiliation: Deparatamento de Veterinária, Universidade Federal de Viçosa, Av. PH Rolfs, s/n, Viçosa, Minas Gerais, 36570-000, Brazil.
authors.forename: Artur K
authors.initials: AK
authors.lastname: Campos
authors.affiliation: Universidade Federal do Vale do São Francisco, Campus de Ciências Agrárias, Rodovia BR 407, Km 12, Lote 543 - Projeto de Irrigação Senador Nilo Coelho, s/n, Petrolina, Pernambuco, 56300-990, Brazil.
authors.forename: Mauricio C
authors.initials: MC
authors.lastname: Horta
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, 05508-270, Brazil.
authors.forename: Aline G A
authors.initials: AG
authors.lastname: Guilloux
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, 05508-270, Brazil.
authors.forename: Hector R
authors.initials: HR
authors.lastname: Benatti
authors.affiliation: Laboratório Especial de Coleções Zoológicas, Instituto Butantan, Av. Vital Brasil 1500, São Paulo, 05503-900, Brazil.
authors.forename: Diego G
authors.initials: DG
authors.lastname: Ramirez
authors.affiliation: Laboratório Especial de Coleções Zoológicas, Instituto Butantan, Av. Vital Brasil 1500, São Paulo, 05503-900, Brazil.
authors.forename: Darci M
authors.initials: DM
authors.lastname: Barros-Battesti
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, 05508-270, Brazil. labruna@usp.br.
authors.forename: Marcelo B
authors.initials: MB
authors.lastname: Labruna
mesh_terms: D000818:Animals; D001938:Brazil; D016000:Cluster Analysis; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D026863:Ixodidae / Q000033:anatomy & histology* / Q000254:growth & development*; D009758:Nymph / Q000033:anatomy & histology; D010802:Phylogeny; D058974:Phylogeography; D017422:Sequence Analysis, DNA
chemical_list: D021903:DNA, Ribosomal Spacer
keywords: Amblyomma cajennense; Amblyomma sculptum; Distribution; ITS2; Nymph