Identificação e caracterização morfológica de hemócitos em Ectemnaspis rorotaense (Floch & Abonnenc) e Ectemnaspis trombetense (Hamada, Py-Daniel & Adle) (Diptera: Simuliidae)

Abstract

The black flies are insects of medical and veterinary importance due to transmit different pathogens to humans and animals however, little is known about the action of defense system of these insects against infection of these pathogens. The hemocytes are cells of immunological system of insects and their functions are to realize phagocytosis, and participte of coagulation process and encapsulation. The aims of this work were to identify and characterize hemocyte types found in Ectemnaspis rorotaense and E. trombetense. The black flies (larvae and pupae) were collected in Presidente Figueiredo municipality, Amazonas state, Brazil. The cells were characterized by optical and transmission electron microscopy. The differential count of cells was performed by light microscopy and to cell differentiation was used morphological characters. The types of cells found in hemolymph were prohemocytes, plasmatocytes, granulocytes and oenocytoids. The prohemocytes were smallest cells observed and characterized by the presence of a large nuclei compared to the cytoplasm. The granulocytes are characterized by the presence of granules with variation in size and shape. This cells were observed large and eccentric nucleus. The oenocytoids have less developed nucleus and located in the central region. The plasmatocytes showed many morphological variations and large projections in cytoplasmatic membrane. In E. rorotaense was found a large number of plasmatocytes, granulocytes and prohemocytes respectively in stages of larvae, pupae, and adults. While in E. trombetense was found was found a large number of prohemocytes, plasmatocytes respectively in larvae and pupae, and the same amount of plasmatocytes and granulocytes in adults. This study cell characterization can be used as a model for future studies on species of blackfly vectors.