EntomoBrasilis (Apr 2013)
Histomorphological Characteristics of Digestive Organs of Lutzomyia wellcomei Fraiha, Shaw & Lainson (Diptera, Psychodidae)
Abstract
Sandflies are important vectors of tegumentary and visceral leishmaniasis in different countries. This study aimed at analyzing the histomorphological characteristics of digestive and reproductive organs in Lutzomyia wellcomei (Fraiha, Shaw & Lainson) using light microscopy techniques. Thirty females from the rural area of Nísia Floresta, Rio Grande do Norte state were selected, microsectioned and analyzed with an optical microscope using conventional hematoxylin-eosin staining. Results show three well-characterized regions in the digestive tube: the stomodeum, mesentery and proctodeum. The stomodeum is lined internally with a basal and epithelial membrane; the mesentery has a peritrophic matrix formed above the stomodeum lining consisting of the simple cubic epithelium overlapping the conjunctive, also common to a capsule of gonadal lining; and the proctodeum, which structurally resembles the mesentery, but with a pyloric sphincter limiting the posterior midgut. Enveloping the digestive tube is the peritoneal membrane, of mesodermal origin. Richly-detailed internal morphological characteristics of L. wellcomei have widened knowledge of this Leishmania braziliensis (Vianna)-transmitting species, an etiologic agent of American tegumentary leishmaniasis.
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