Caracterização morfológica das glândulas de Brindley e metasternais, identificação química das suas secreções e comportamento sexual em Triatoma brasiliensis (Reduviidae, Triatominae)

• Ano de defesa: 2005
• Autor(a) principal: Vitta, Ana Cristina Renna de
• Orientador(a): Vilela, Evaldo Ferreira
• Banca de defesa: Lorenzo, Marcelo Gustavo , Serrão, José Eduardo , Pereira, Marcos Horácio , Diotaiuti, Liléia G.
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Entomologia
• Departamento: Ciência entomológica; Tecnologia entomológica
• País: BR
• Palavras-chave em Português: Doença de Chagas; Triatomíneos; Feromônios; Glândulas; Morfologia; Triatoma brasiliensis
• Palavras-chave em Inglês: Chagas disease; Triatominae; Pheromones; Glands; Morphology; Triatoma brasiliensis
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::PARASITOLOGIA::ENTOMOLOGIA E MALACOLOGIA DE PARASITOS E VETORES
• Link de acesso: http://locus.ufv.br/handle/123456789/3947

Adults of Triatoma brasiliensis (Reduviidae) show two pairs of exocrine glands: the metasternal and the Brindley glands. The first one is located in the ventral part of the metathorax, while Brindleys glands are found in the lateral part of the superior metathorax. In both glands, the secretory cells correspond to type III, according to the classification of Noirot & Quennedey (1991). Metasternal glands present tricoid sensilla next to their external opening. In the cytoplasm of the secretory cells of these glands granules strongly stained were usually found, suggesting that these glands produce different substances than those of Brindleys glands. The substances found in the secretion of the Brindleys glands of T.brasiliensis were identified for the first time, as a mixture of five fatty acids: acetic; propanoic; isobutyric; butyric and 2-methyl-butyric acids. Isobutiric acid was found to be the most abundant compound and no qualitative or quantitative differences were observed in relation to gland contents for both sexes. Our results demonstrated that the metasternal glands of T. brasiliensis are also involved in the synthesis of volatile substances. These glands produce basically ketones and alcohols, 3-pentanone was the major constituent of the mixture found in these glands for both sexes. After their mechanical disturbance, adults of T. brasiliensis emitted a mixture of 10 different compounds consisting of ketones, alchools and fatty acids, including substances from both metasternal and Brindleys glands,. Finally, we analyzed the sexual behavior of T. brasiliensis: the copula last, in average, 6 ± 1 min and the number of male attempts to copulate varied according to the insect age. Females of T. brasiliensis showed three types of rejection in response to male attempt to copulate: flattening, abdominal movements and evasion. The analysis of the female behavior revealed that the number of rejections in response to male attempts stayed the same during the pre-feeding period. After feeding a gradual decrease in the number of rejections was observed, diminishing until reaching zero rejection at approximately the day 8 post-feeding. We suggest a behavioral mechanism in the female, after feeding, that may trigger the acceptance of the male attempt to copulate in T. brasiliensis. The relevance of the results for understanding the behavioral repertoire of the specie, particularly in the sexual context, is discussed.