Pairing of Schistosoma mansoni males in infected Syrian hamsters.

Pairing of male schistosomes in the liver of infected hamsters was recorded with Egyptians S. mansoni strain. The homospecific male pairs never carried each other in the gynaecophoric duct, but they being closed in either central or hepatic veins. Other perfused males and females en copula showed normal mating behaviour. The paired males were more or less in the same size. The random sexed miracidia used resulted in obtaining 1:2.1 female/male ratio. It is concluded that the random increase of male schistosomes may create the male pairing behaviour. Also, the migration of female against the blood stream to the mesenteric plexus of the host and the failure of male to catch them may lead to this homosexual pairing. The black haemozoin-like substance seen in mature females was also observed in the pairing males and this probably reflects the effect of scarcity or migration of females to the mesenteric plexus.

A new record of phoretic mites on honey bee Apis mellifera L. in Egypt.

Five species of mites, belonging to different families, were found infesting honeybee workers, Apis mellifera L., in different apiaries in Al-Gharbiya Governorate, Nile Delta. All the identified species except Varroa jacobsoni Oudemans (Varroidae) are new records for the phoretic bee mites in Egypt. These are Neocypholaelaps indica Evans (Ameroseiidae), Pediculochelus raulti Lavoipiere (Pediculochelidae), Tarsonemus indoapis Lindquist (Tarsonemidae) and Chaetodactylus osmiae (dufour) (Chaetodactylidae). The host parasite relationship was discussed. A brief diagnosis with diagrammatic illustrations is given.

Studies on larval digenetic trematodes of xiphidiocercariae from some Egyptian fresh water snails.

Six xiphidiocercariae are described from seven Egyptian snails, includes Cleopatra bulimoides, Malanoides tuberculata, Lymnaea cailliaudi, Bulinus truncatus, Biomphlaria alexandrina and Lanistes carinatus collected from Giza (Abou Rawash) and Qualiobyia (Qualiuob). Details are presented on the morphology, behavior of the cercariae, as well as other larval stages within the snails, with discussion and comparison between the previously described cercariae.