[Sergentomyia (Rondanomyia) ingrami Newstead, 1914, Sergentomyia (Rondanomyia) dureni Parrot, 1934 and Sergentomyia hamoni Abonnenc, 1958 (Diptera Phlebotomidae). Morphology of immature stages and biocological accounts. (author's transl)]

Morphology of the eggs surface of ten Brazilian species of phlebotomine sandflies (Diptera: Psychodidae)

The chorionic sculpturing of ten Brazilian sandfly species, Nyssomyia antunesi (Coutinho), N. whitmani (Antunes and Coutinho), Bichromomyia flaviscutellata (Mangabeira), B. olmeca nociva (Young and Arias), Evandromyia walkeri (Newstead), E. williamsi (Antunes and Coutinho), Deanemyia maruaga (Alves, Freitas and Barrett), D. samueli (Deane), Viannamyia furcata (Mangabeira) and Lutzomyia dispar (Martins and Silva), was examined using scanning electron microscopy. Eggs of the last seven species, as well as the genera Deanemyia and Viannamyia, are described for the first time. In total, five patterns of chorionic sculpturing were found: polygonal, connected parallel ridges, unconnected parallel ridges, volcano-like and placoid. The last one is a new chorionic sculpture pattern, which was observed in D. samueli. These structures are illustrated and discussed. These results show that egg morphology can be used in phlebotomine taxonomy, both at generic and specific levels.

Morphological Description of the Immature Stages of Nyssomyia umbratilis (Ward & Frahia) (Diptera: Psychodidae: Phlebotominae), the Main Vector of Leishmania guyanensis Floch (Kinetoplastida: Trypanosomatidae) in the Brazilian Amazon Region

Nyssomyia umbratilis (Ward & Frahia) is the main vector of Leishmania guyanensis in the Brazilian Amazon region, where it is widely distributed. Studies have hypothesized that this phlebotomine is part of a cryptic species complex, spatially delimited by the Amazonian river systems, and with different transmission potential of L. guyanensis. In the present study, the immature stages of N. umbratilis are described from laboratory-reared specimens originating from the states of Amazonas and Pará, Brazil. Based on scanning electron and optical microscopy examinations, fine morphological structures (eggshell, setae, and mouthparts of larvae and pupae) are presented. A new form of sandfly pupae sexing (non-invasive) is also provided. The correct identification of insect is extremely important for the epidemiology of certain diseases. However, only the morphological characters of adult can be insufficient to separate accurately the closely related species. It is expected that the present description may contribute to solve the taxonomic problem involving N. umbratilis.

Morphology and ultrastructure of spiracles in phlebotomine sandfly larvae

The morphology and ultrastructure of the larval spiracle system of three phlebotomine sandfly species, Phlebotomus perniciosus, P. perfiliewi and P. papatasi, were examined by scanning (SEM) and transmission (TEM) electron microscopy and by confocal scanning laser microscopy (CSLM). During larval development, thoracic and abdominal spiracles show considerable modifications. In fourth instar larvae, the spiracles consist of a plate with a sclerotized central portion and a peripheral circle of papillae. The latter is distinctive in the larvae of P. papatasi, which are readily distinguished from the other species. Opening clefts across the papillae communicate with an internal chamber that encircles an electrondense plug. Many cylindrical projections cross the chamber, uniting the central plug with the larval body, forming an air filter. Spiracular development in successive larval instars has both a taxonomic and adaptive value.

Morphological study of the larval spiracular system in eight Lutzomyia species (Diptera: Psychodidae)

The morphology of the spiracles of fourth instar larva in eight sandfly species were examined by light and scanning electron microscopy. Species studied were: Lutzomyia longipalpis (Lutz & Neiva), L. ovallesi (Ortiz), L. youngi Feliciangeli & Murillo, L. evansi (Nuñez-Tovar), L. trinidadensis (Newstead), L. migonei (França), L. absonodonta Feliciangeli, and L. venezuelensis (Floch & Abonnenc). In larvae of all eight species both thoracic and abdominal spiracles are located at the top of a globular bulge. Their structure consists of a spiracular plate with a sclerotized central portion and a rose-like peripheral portion. The latter has circularly arranged papillae, separated from each other by elongated septa. Each papilla is longitudinally crossed by a fine cleft dividing it into two identical parts. The taxonomic and adaptative value of spiracular morphology is discussed.