Ixodid tick attacks on man in Israel: medical implications.

Various species of ixodid ticks that have been recorded to attack man were surveyed, and boutonneuse fever caused by Rickettsia conorii, which is transmitted in Israel by Rhipicephalus sanguineus s.l., is reviewed. Only in one case were a complement fixation test and exact determination of the species of the tick performed. Tick toxicosis and tick paralysis are discussed, and the possibility of human babesiosis and Lyme disease or erythema chronicum migrans appearing in Israel is considered.

Some ecological observations on two east-Mediterranean species of Haemaphysalis ticks parasitizing domestic stock.

Haemaphysalis cretica and H. otophila thrive in the Mediterranean phytogeographic zone of the eastern Mediterranean area. Haemaphysalis otophila has a wide geographical distribution, H. cretica is more restricted. The adults of both species parasitize sheep and goats, and transmit diseases. The pre-imaginal stages feed on reptiles and small mammals. Adults attach to their hosts only during winter. The pre-oviposition period is long and the embryonic development is slow. Larvae hatch in spring and attach to their hosts in early summer; nymphs follow somewhat later and descend off their hosts in late summer. There is only one generation per year for each of the species.

A new observation on spermateleosis in ticks.

The first phase of spermiogenesis in argasid and ixodid ticks is described. The inner core of the spermatid passes through the outer sheath so that speriogenesis is permitted to follow its course. The outer sheath is not ruptured in the process, but a well-defined operculum opens to let the inner core through. The opening of the operculum is a clear-cut indication of the beginning of spermiogenesis. In the examined species speriogenesis begins in Argasidae when the male transfers the spermatophore to the female genital opening, whereas in Ixodidae it starts only after the endospermatophore has reached the female genital tract.

Scanning and transmission electron microscopy of the spermiophores of Ornithodoros ticks: an attempt to explain their motility.

The spermiophores of two tick species, the kangaroo tick, Ornithodoros gurneyi and the cave tick, Ornithodoros tholozani have been examined by scanning and transmission electron microscopy. The anterior end (head) of the spermiophore is a hemisphere covered with a hexagonal network of small projections. The rest of the spermiophore is covered with longitudinal ridges, seen in sections as cellular processes whose membranes are attached only at their anterior ends by specialized 'feet'. In the cytoplasm of the sperm cell body and just beneath the cellular processes are find filaments, which form a continuous layer in O. tholozani and bundles in O. gurneyi. Fibrils tend to be situated beneath the larger cellular processes. In scanning micrographs helical constrictions have been observed in the posterior parts of some spermiophores. It is proposed that certain of the movements observed by light microscopy in living cultures of spermiophores may be explained by contraction of the cytoplasmic filaments seen in the electron microscope.

Spermatophore formation and sperm transfer in Ornithodoros ticks.

In seven species of Ornithodoros and two species of Argas ticks the spermatophore is formed outside the male body in three consecutive stages: (i) the outer bulb, the ectospermatophore, is formed; (ii) it is filled with sperm; and (iii) the inner capsules, the endo-spermatophore, are extruded into the ecto-spermatophore. The morphologies of the ecto-spermatophore and the endo-spermatophore are related to their biological functions. Eversion and evagination of the endo-spermatophore after deposition of the spermatophore on the female genital opening, as well as transfer of sperm from ecto-spermatophore to endo-spermatophore, are described.