Cytotaxonomy of Dipetalogaster maxima Uhler, 1894 (Hemiptera, Reduviidae, Triatominae)

The Triatomini tribe consists of ten genera and is regarded as one of the most important tribes from epidemiological point of view. The genus Dipetalogaster Usinger, 1939 is composed only by the species Dipetalogaster maxima Uhler, 1894. This triatomine is exclusive of the Mexico and is a potential vector for Chagas disease. Besides the epidemiological importance, the insects of the Triatominae subfamily are important biological models for cytogenetic studies. Therefore, in order to contribute to the knowledge on the reproductive biology and assist in citotaxonomy of D. maxima, this study aimed to describe spermatogenesis, as well as confirm the karyotype and heterochromatic patterns of this Mexican triatomine species. The seminiferous tubules were torn, fixed to a cover slip and underwent the cytogenetic technique of Lacto-acetic orcein and C-banding. Through the cytogenetics analysis of testicular material D. maxima it was possible to confirm the karyotype (2n = 22), describe the stages of spermatogenesis and characterize the heterochromatic pattern (restricted to sex chromosome Y) of the species. D. maxima showed the same arrangement of heterochromatin described for Triatoma lecticularia (Stål, 1859) (a species that occur in United States of American and Mexico and is phylogenetically related with D. maxima), highlighting the importance of this analysis as an optimization tool to explore phylogenetic correlations.