Dados do Trabalho

Título

Triatoma guazu Lent and Wygodzinsky is a synonym of Triatoma williami Galvão, Souza, and Lima

Introdução

Triatoma guazu and Triatoma williami are found in human dwellings and are potential vectors of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Triatoma guazu was described based solely on a single female specimen, from the municipality of Villarica, Guairá Department, Paraguay, and posteriorly, a male from Barra do Garças, Mato Grosso, Brazil was described and designated as the allotype of this species. Triatoma williami is found in the central-west of Brazil between Goiás, Mato Grosso, and Mato Grosso do Sul. However, the taxonomic status of these species is questioned. Previous studies indicate the lack of isoenzymatic diagnostic loci, morphometric similarity, low genetic divergence, and close evolutionary relationship of these species.

Objetivo(s)

To review and compare the taxonomic status of T. williami and T. guazu.

Material e Métodos

Morphological analysis. We examined 44 individuals deposited in Coleção Entomológica do Instituto Butantan and Coleção de Triatomíneos do Instituto Oswaldo Cruz. Some specimens were selected for analysis of female and male genitalia. Geometric morphometrics. The adult head capsule was analyzed for the two species, in addition to the outgroup consisting of Triatoma matogrossensis and three specimens of Triatoma oliveirai. The analysis was performed using TpsDig version v. 2.05 and JMP 3.2.6. Molecular analysis. A total of 64 DNA sequences of Triatoma brasiliensis, T. guazu, Triatoma jatai, T. matogrossensis and T. williami were retrieved from GenBank for 16S, COI, COII and CytB. DNA sequence data were aligned separately for each marker and identified the number of variable sites, using MEGA-X. A pairwise divergence calculation was performed in the MEGA-X program, using the Kimura-2-parameters as the substitution model. Species comparisons were performed by calculating the difference between inter and intraspecific genetic distances. Here, we considered as ‘true’ species those which interspecific divergences were above intraspecific divergences observed for Triatoma species.

Resultados e Conclusão

The morphological diagnostic characteristic among these species is the difference in the connexivum spots pattern, which has been recognized as a phenotypic variation that exists among populations resulting from ecological diversity. Furthermore, our analysis also revealed the morphometric similarity and low genetic divergence between these species. Therefore, we consider T. guazu as a synonym of T. williami.

Palavras-chave

Triatominae, synonym, taxonomy

Área

Eixo 04 | Entomologia / Controle de Vetores