Differentiation between Triatoma arthurneivai and Triatoma wygodzinskyi (Hemiptera: Reduviidae: Triatominae) using cytotaxonomy

Abstract

ABSTRACT. Using classic morphometric techniques to examine the head and thorax of Triatoma specimens, researchers identified a possible taxonomic problem involving T. arthurneivai (Lent & Martins) and T. wygodzinskyi (Lent). A recent geometric morphometric study indicated that the insects captured outside the Serra do Cipó region, State of Minas Gerais, Brazil, were T. wygodzinskyi. The misidentification of T. arthurneivai as T. wygodzinskyi could result in several problems associated with entoepidemiological lifting, the biological characterization of the species, and phylogenetic reconstruction. For the first time, we describe the use of cytogenetic analysis as a tool for differentiation between T. arthurneivai and T. wygodzinskyi. The results indicated that both species had the same number of chromosomes 2n = 22 (20A + XY). However, analyses of spermatocytes during early prophase indicated that it was possible to differentiate T. arthurneivai and T. wygodzinskyi, because only T. arthurneivai exhibited heteropycnotic blocks distributed in the chromatin. Therefore, we highlight the analysis of spermatocytes as a taxonomic tool for the characterization of T. arthurneivai and T. wygodzinskyi, and suggest that the technique can be used for entoepidemiological lifting in vector control programs. Thus, the results presented here, in conjunction with morphometric analyses, are of utmost taxonomic and epidemiological importance for the identification of T. arthurneivai and T. wygodzinskyi specimens.

Dichotomous Keys Based on Cytogenetic Data for Triatomines Reported in Brazilian Regions with Outbreaks of Orally Transmitted Chagas Disease (Pernambuco and Rio Grande Do Norte)

“…Cytogenetic studies have provided insight into reproductive [39][40][41], physiological [42,43], evolutionary [44][45][46], systematic [34,47], and taxonomic [33,36,48] aspects of Triatominae. Cytotaxonomy was initially developed in 1950, when Schreiber and Pellegrino [49] described some karyotypes of species from South America.…”

Revisiting the Chromosomal Diversification of the Genus Rhodnius (Stål, 1859) (Hemiptera, Triatominae)

“…25 Recently, the heterochromatin pattern and the composition of AT and CG was one of the tools used to describe R. taquarussuensis Rosa et al 27 However, molecular analyzes and experimental crosses showed that R. taquarussuensis was R. neglectus with chromosomal polymorphisms. 28 Based on this, it is evident that although cytogenetic analyses are of great taxonomic importance, 29,30 the confirmation that different cytotypes represent valid taxa must be performed through integrative taxonomy. 31 Thus, we characterize the AT-and CG-rich DNA pattern for the genus Rhodnius, and we suggest that the pattern of CG-rich heterochromatin in the autosomes of these vectors evolved independently in pallescens, pictipes, and prolixus groups.…”

CytoKey: Identification Key for the Chagas Disease Vectors of the Largest Brazilian Urban Center (São Paulo State), Based on Cytogenetic Data

“…13,14 However, problems in correctly identifying species can lead to an incorrect panorama of distribution of Chagas disease vectors as 15 demonstrated that the species that exists in São Paulo is Triatoma wygodzinsky (Lent, 1951) that was incorrectly identified as T. arthurneivai (endemic to the state of Minas Gerais). 5 Cytogenetic tools are contributing to the taxonomy of triatomines; for example, Alevi et al 16 recently characterized the prophase cells of T. arthurneivai and T. wygodzinsky and differentiated the species easily, highlighting the applicability of the cytological analyzes in the correct identification of the species. Based on this information, we developed an identification key for the triatomines of the state of São Paulo, based on cytogenetic data.…”