Morphological Characterization of the Antennal Sensilla of the Afrotropical Sand Fly, Phlebotomus duboscqi (Diptera: Psychodidae).

We investigated by scanning electron microscopy the morphology, distribution, and abundance of antennal sensilla of females Phlebotomus duboscqi sand fly, an important vector of zoonotic cutaneous leishmaniasis at Afrotropical region. Thirteen well-differentiated sensilla were identified, among six types of cuticular sensilla. The probable function of these sensillary types is discussed in relation to their external structure and distribution. Five sensillary types were classified as olfactory sensilla, as they have specific morphological characters of sensilla with this function. Number and distribution of sensilla significantly differed between antennal segments. The results of the present work, besides corroborating in the expansion of the morphological and ultrastructural knowledge of P. duboscqi, can foment future electrophysiological studies for the development of volatile semiochemicals, to be used as attractants in traps for monitoring and selective vector control of this sand fly.

The characterization of the fat bodies and oenocytes in the adult females of the sand fly vectors Lutzomyia longipalpis and Phlebotomus papatasi.

The fat body (FB) is responsible for the storage and synthesis of the majority of proteins and metabolites secreted into the hemolymph. Oenocytes are responsible for lipid processing and detoxification. The FB is distributed throughout the insect body cavity and organized as peripheral and perivisceral portions in the abdomen, with trophocytes and oenocytes attached to the peripheral portion. Here, we investigated the morphology and the subcellular changes in the peripheral and perivisceral FBs and in oenocytes of the sand flies Lutzomyia longipalpis and Phlebotomus papatasi after blood feeding. In L. longipalpis two-sized oenocytes (small and large) were identified, with both cell types displaying well-developed reticular system and smooth endoplasmic reticulum, whereas in P. papatasi, only small cells were observed. Detailed features of FBs of L. longipalpis and P. papatasi are shared either prior to or after blood feeding. The peripheral and perivisceral FBs responded to blood feeding with the development of glycogen zones and rough endoplasmic reticulum. This study provides the first detailed description of the FBs and oenocytes in sand flies, contributing significantly towards are better understanding of the biology of such important disease vectors.

Primary culture of venom glands from the Brazilian armed spider, Phoneutria nigriventer (Araneae, Ctenidae).

Phoneutria spider venoms are a rich source of bioactive components. The limited amounts of crude material available, however, can be considered as a major hindrance for a faster development in the field. In the present study, we attempted to establish primary cultures of venom glands of Phoneutria nigriventer as an alternative, in vitro source of venom. Three different developmental stages were tried as starting materials: whole embryo (inside the cocoon), nymph (early after cocoon hatching) and young adult (1 year after cocoon hatching). The embryonic cells remained in suspension in the primary cultures, with no signs of adhesion or differentiation, for about 6 months. Nevertheless, this culture was useful for the first chromosome C-banding of Phoneutria. An average of 29+/-1 acrocentric chromosomes were found. Striated muscle cells were the only kind of cells in the culture of venom glands from Phoneutria nymphs. The most promising results were achieved with 1-year-old specimens. Besides muscle, adherent epithelial cells were also obtained in culture. Although these cells remained in culture for a short time (up to 48 h) immunochemical analysis of the culture supernatant evidenced the presence of Phoneutria venom components. This can be considered as a first step toward the functional cultures of venom glands of Phoneutria spiders.