Morphological and histological study of eggs of six species of the Triatoma genus (Hemiptera: Reduviidae)

• Published in: Neotropical entomology 2007-09, Vol.36 (5), p.798-806
• Main Authors: Obara, Marcos T, da Rosa, João A, da Silva, Nilza N, Ceretti, Jr, Walter, Urbinatti, Paulo R, Barata, José M S, Jurberg, José, Galvão, Cleber
• Format: Article
• Language: eng ; por
• Subjects: Animals; Hemiptera; Lima; Microscopy, Electron, Scanning; Ovum - ultrastructure; Reduviidae; Triatoma; Triatoma - classification; Triatominae; Trypanosoma cruzi
• ISSN: 1519-566X; 1678-8052
• DOI: 10.1590/S1519-566X2007000500023

The objective of this study was to analyze the morphological and histological characteristics of eggs from six triatomine species in order to obtain a generic and specific characterization of this group of Trypanosoma cruzi vectors and better understand their phylogenetic and taxonomic aspects. The eggs of the respective species came from the collection of the Laboratório de Triatomíneos e Culicídeos da Faculdade de Saúde Pública/USP, from the Insetário do Serviço Especial de Saúde de Araraquara - SESA and from the Triatomine insectary of the Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos (FIOCRUZ), in Rio de Janeiro. Morphological studies were done with optical microscopy and scanning electron microscopy. Histological analyses used only optical microscopy. All of the species analyzed showed a predominance of hexagonal cells. The exchorion of Triatoma breyeri Del Ponte, T. costalimai Verano Galvão, and T. tibiamaculata (Pinto) consists of unornamented cells, overlapping or slightly separated, with a smooth, padded appearance. Meanwhile, in T. matogrossensis Leite Barbosa, T. sherlocki Papa, Juberg, Carcavallo, Cerqueira Barata, and T. williami Galvão, Souza Lima, the exchorion cells are ornamented on their entire surface with perforations and fissures. Egg histology showed undulations, pores, and orifices. The study helps to expand the generic and specific knowledge of the Triatominae subfamily. The characteristics identified in the exchorion of the eggshells can help separate close species. These new parameters will back the elaboration of future dichotomous keys, help to determine each vector species role and expand knowledge of the various species.