Morphology of the spermathecae of twelve species of Triatominae (Hemiptera, Reduviidae) vectors of Chagas disease

Abstract

Trypanosoma cruzi, the etiological agent of Chagas disease, is transmitted by triatomines that have been described in a large number of studies. Most of those studies are related to external morphology and taxonomy, but some biochemical, genetic and physiological studies have also been published. There are a few publications in the literature about the internal organs of Triatominae, for instance the spermathecae, which are responsible for storing and maintaining the viability of the spermatozoids until the fertilization of the oocytes. This work aims to study the spermathecae of twelve species of triatomines obtained from the Triatominae Insectarium of the Faculty of Pharmaceutical Sciences, UNESP, Araraquara, using optical microscopy and scanning electron microscopy. The spermathecae of the twelve species studied showed three morphological patterns: a) P. herreri sn, P. lignarius, P. megistus, Triatoma brasiliensis, T. juazeirensis, T. sherlocki and T. tibiamaculata have spermathecae with a thin initial portion and an oval-shaped final portion; b) R. montenegrensis, R. nasutus, R. neglectus, R. pictipes and R. prolixus have tubular and winding spermathecae; c) T. infestans has oval spermathecae. In addition to the three morphological patterns, it was noted that each of the twelve species has particular features that differentiate them.

Do not judge a book by its cover: would Triatoma tibiamaculata (Pinto, 1926) belong to Triatoma Laporte, 1832, or to Panstrongylus Berg, 1879, with misleading homoplasies?

“…nov. (more specifically in the structures of the eighth ventral segment as well as between setae) were observed [ 54 ]. Furthermore, Nascimento et al [ 55 ] also observed similarities between spermathecae morphology from P. lignarius, P. megistus and P. tibiamaculatus comb. nov., and Mello et al [ 56 ] recorded a relationship between exocorial cells in eggs of P. tibiamaculatus comb.…”

Triatoma pallidipennis (Stål, 1872) (Hemiptera: Reduviidae) and its potential for infestation in Tecozautla, Hidalgo state, Mexico

“…It is known that female triatomines can store sperm for months or years, however, studies of this are scarce (Vöcking et al 2013, Nascimento et al 2017). We observed a female T. pallidipennis since her capture, and the number of fertile laid eggs showed that it had previously copulated before being captured.…”

Histological description of immature Chironomus columbiensis (Diptera: Chironomidae): A potential contribution to environmental monitoring

“…This is an important confirmation considering that sensitivity to contaminants and histopathological changes induced by contamination can vary within a wide range, depending on the species (Bernet, Schmidt, Meier, Burkhardt‐Holm, & Wahli, ; Glover et al, ). Taxonomically, several studies have shown that the study and analysis of the internal morphology of insects is a useful tool for this group's systematics (Deans, Mikó, Wipfler, & Friedrich, ; Nascimento et al, ), including Diptera (King, ; King, ; Kotrba, ; Mazurkiewicz & Kubrakiewicz, ). The taxonomic identification of species of the genus Chironomus has been a challenge for experts of this group, due to the external morphological similarity among species (Lindeberg & Wiederholm, ).…”