Morphologic and morphometric analysis of a Hemogregarina of Rhodnius brethesi Matta, 1919 (Hemiptera, Reduviidae: Triatominae) naturally infected

Abstract

Hemogregarines are intraerythrocytic endoparasites in a wide variety of vertebrates. Their identification has been based mainly on the morphologic and morphometric descriptions. In this paper, we describe the morphology and morphometry of a hemogregarine found naturally infecting R. brethesi. Parasitological researches were made in the hemolymph, gut contents and salivary glands from 174 specimens of R. brethesi. Morphological descriptions and morphometric analysis of the parasitic forms were based on digital photomicrographs. The variables were: external morphology, presence or absence of capsule, total length, absolute width, and number of sporozoites in each sporocyst; in the case of sporozoites, we also recorded the length, breadth, shape and position of the nucleus and the presence or absence of cytoplasmic pigment. Oocysts, sporoblasts, sporocysts, and sporozoites of a hemogregarina were described. One 4th instar nymph was simultaneously infected with T. rangeli and hemogregarine. The morphometric characteristics observed in these parasites may indicate that it is a new hemogregarina, and not yet reported for this triatomine. The identification of the reptiles blood as the origin blood feeding of R. brethesi associated with great presence of geconídeo Thecadactylus rapicauda Houttuynia in the ecotope of this triatomine suggests this reptile as a possible definitive host.