title: Does Triatoma brasiliensis occupy the same environmental niche space as Triatoma melanica?
abstract: BACKGROUND
  Triatomines (Hemiptera, Reduviidae) are vectors of Trypanosoma cruzi, the causative agent of Chagas disease, one of the most important vector-borne diseases in Latin America. This study compares the environmental niche spaces of Triatoma brasiliensis and Triatoma melanica using ecological niche modelling and reports findings on DNA barcoding and wing geometric morphometrics as tools for the identification of these species.
  
  
  METHODS
  We compared the geographic distribution of the species using generalized linear models fitted to elevation and current data on land surface temperature, vegetation cover and rainfall recorded by earth observation satellites for northeastern Brazil. Additionally, we evaluated nucleotide sequence data from the barcode region of the mitochondrial cytochrome c oxidase subunit I (CO1) and wing geometric morphometrics as taxonomic identification tools for T. brasiliensis and T. melanica.
  
  
  RESULTS
  The ecological niche models show that the environmental spaces currently occupied by T. brasiliensis and T. melanica are similar although not equivalent, and associated with the caatinga ecosystem. The CO1 sequence analyses based on pair wise genetic distance matrix calculated using Kimura 2-Parameter (K2P) evolutionary model, clearly separate the two species, supporting the barcoding gap. Wing size and shape analyses based on seven landmarks of 72 field specimens confirmed consistent differences between T. brasiliensis and T. melanica.
  
  
  CONCLUSIONS
  Our results suggest that the separation of the two species should be attributed to a factor that does not include the current environmental conditions. However, as the caatinga is a biome that has existed in the area for at least the last 18,000 years, past conditions might have had an influence in the speciation process. The DNA Barcoding approach may be extended to these members of the subfamily Triatominae.
authors.affiliation: Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, CEP 30.190-002, Belo Horizonte, Minas Gerais, Brazil. rita@cpqrr.fiocruz.br.
authors.forename: Rita de Cássia Moreira
authors.initials: Rde C
authors.lastname: de Souza
authors.affiliation: Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, CEP 30.190-002, Belo Horizonte, Minas Gerais, Brazil. gabriel.cbio@gmail.com.
authors.forename: Gabriel H
authors.initials: GH
authors.lastname: Campolina-Silva
authors.affiliation: Secretaria de Saúde do Estado do Ceará,, Fortaleza, Ceará, Brazil. cmendoncab@gmail.com.
authors.forename: Claudia Mendonça
authors.initials: CM
authors.lastname: Bezerra
authors.affiliation: Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, CEP 30.190-002, Belo Horizonte, Minas Gerais, Brazil. diotaiuti@cpqrr.fiocruz.
authors.forename: Liléia
authors.initials: L
authors.lastname: Diotaiuti
authors.affiliation: IMBIV-CONICET, Casilla de Correo 495, 5000, Córdoba, Argentina. david.gorla08@gmail.com.
authors.forename: David E
authors.initials: DE
authors.lastname: Gorla
mesh_terms: D000818:Animals; D014355:Chagas Disease / Q000469:parasitology / Q000635:transmission*; D017753:Ecosystem; D007303:Insect Vectors / Q000145:classification / Q000235:genetics / Q000469:parasitology / Q000502:physiology*; D014224:Triatoma / Q000145:classification / Q000235:genetics / Q000469:parasitology / Q000502:physiology*; D014349:Trypanosoma cruzi / Q000502:physiology