The development of Psychodiella sergenti (Apicomplexa: Eugregarinorida) in Phlebotomus sergenti (Diptera: Psychodidae)

Abstract

SUMMARYPsychodiella sergenti is a recently described specific pathogen of the sand fly Phlebotomus sergenti, the main vector of Leishmania tropica. The aim of this study was to examine the life cycle of Ps. sergenti in various developmental stages of the sand fly host. The microscopical methods used include scanning electron microscopy, transmission electron microscopy and light microscopy of native preparations and histological sections stained with periodic acid-Schiff reaction. Psychodiella sergenti oocysts were observed on the chorion of sand fly eggs. In 1st instar larvae, sporozoites were located in the ectoperitrophic space of the intestine. No intracellular stages were found. In 4th instar larvae, Ps. sergenti was mostly located in the ectoperitrophic space of the intestine of the larvae before defecation and in the intestinal lumen of the larvae after defecation. In adults, the parasite was recorded in the body cavity, where the sexual development was triggered by a bloodmeal intake. Psychodiella sergenti has several unique features. It develops sexually exclusively in sand fly females that took a bloodmeal, and its sporozoites bear a distinctive conoid (about 700 nm long), which is more than 4 times longer than conoids of the mosquito gregarines.

Polymerase chain reaction-based assay for the detection and identification of sand fly gregarines inLutzomyia longipalpis, a vector of visceral leishmaniasis

“…sergenti is harmful to its host Ph. sergenti under laboratory conditions and that the parasite's effects can be influenced by environmental factors (Lantova et al ). Furthermore, the severity of a gregarine infection ( Ascogregarina culicis ) on its natural host ( Aedes aegypti ) was shown to vary both among four different geographic origins of the parasite and among three different populations of Ae.…”

The Symbiotic Spectrum: Where Do the Gregarines Fit?

“…The effects range from high mortalities in ascidians [28] to negligible effects in bivalves [30]. In vitro experiments in insects have suggested that the number of gregarines can affect, for example, the overall flight performance and mating success of dragonflies [31], increase adult mortality and inhibit ovarian and fat body development in the western corn rootworm [32], mortality of immature sand fly stages and a negative effect on the survival of adult males and females [33]. Due to these negative effects on hosts that can be either disease vectors or pests, the potential of gregarines as biological control agents has been discussed [33,34], but their usefulness is often questioned by the authors.…”

Morpho-functional characterization and esterase patterns of the midgut of Tribolium castaneum Herbst, 1797 (Coleoptera: Tenebrionidae) parasitized by Gregarina cuneata (Apicomplexa: Eugregarinidae)

“…Therefore, nutritional depletion might result in size and weight reduction, as observed in the larvae of beetles Dermestes maculatus (Lord and Omoto, 2012) and Tenebrio molitor (Harry, 1967). Furthermore, the physiological processes of the host, including reproduction and development, might be compromised (Bouwma et al, 2005;Er and Gokce, 2005;Harry, 1970;Lange and Lord, 2011;Lantova et al, 2011;Lord and Omoto, 2012;Schreurs and Janovy, 2008), and eventually lead to its death (Harry, 1967;Valigurová, 2012).…”