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Corresponding author: Carlos Eduardo Almeida ( almeida_ce@hotmail.com ) Academic editor: Guanyang Zhang
© 2018 Carolina Dale, Carlos Eduardo Almeida, Vagner José Mendonça, Jader Oliveira, João Aristeu da Rosa, Cleber Galvão, Jane Costa.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Dale C, Almeida CE, Mendonça VJ, Oliveira J, da Rosa JA, Galvão C, Costa J (2018) An updated and illustrated dichotomous key for the Chagas disease vectors of Triatoma brasiliensis species complex and their epidemiologic importance. ZooKeys 805: 33-43. https://doi.org/10.3897/zookeys.805.25559
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In the subfamily Triatominae, Triatoma exhibits the largest number of species, which are arranged in complexes. For the T. brasiliensis species complex, recent investigations based on results of geometric morphometrics combined with phylogeny have provided evidence that it should be composed of seven species: T. brasiliensis, T. bahiensis, T. juazeirensis, T. lenti, T. melanica, T. petrocchiae, and T. sherlocki, in which T. brasiliensis is divided in two subspecies: T. b. brasiliensis and T. b. macromelasoma. A taxonomic key is presented to identify each taxon. Among members of this complex, T. b. brasiliensis is the most important in an epidemiologic context, due to its high prevalence in natural infection by Trypanosoma cruzi combined with a pronounced adaptation to domiciliary habitats. However, some members may be currently invading and colonizing homes, a process known as domiciliation. Therefore, the key presented here may be potentially useful for researchers as well as those involved in vector control measures.
kissing bugs, morphological key, species group
Chagas disease is an infection caused by the etiologic agent Trypanosoma cruzi (Chagas, 1909), a protozoan transmitted to humans and other mammals through the feces of infected hematophagous insects of subfamily Triatominae. Currently, this group consists of more than 150 species, of which more than 65 are found in Brazil (
Triatoma brasiliensis species complex represents a monophyletic unit (
To date, most of measures to combat the transmission of Chagas disease have been focused on vector control. Defining the taxonomic status and correctly identifying vectors of the T. brasiliensis complex is crucial to the success of surveillance actions, because each species exhibits its own epidemiological importance (
Most of insects studied here are deposited in the Entomological Collection of Oswaldo Cruz Institute (CEIOC), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil. The type species were always checked if possible, as previously detailed (
According to
A pictorial dichotomous key for the T. brasiliensis species complex was built up as follows:
The epidemiological profile of Chagas disease has changed, both in endemic areas and in other regions due to human migration, resulting in dissemination to countries where there is no vector transmission (
Members of the T. brasiliensis complex have been found in 12 Brazilian states and show mainly allopatric and parapatric distribution patterns, (
Studies on members of the complex have demonstrated that T. b. brasiliensis is the most important species in epidemiological terms. This species exhibits high intra-domiciliary infestation and infection rates (
We recommend disseminating a version of this document in Portuguese to those involved in vector control measures. However, despite the contribution presented here, we still face some taxonomic challenges regarding this complex. There is no available key to differentiate immature stages for all members of this complex, which may complicate the correct identification of these forms. As mentioned above (
Financial support was provided by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, process numbers 2016/08176-9 and 2017/09088-9).