Mating strategies and spermiogenesis in ixodid ticks

Mate-seeking and sperm-transfer in the ixodid hard ticks, which include imp ortant vectors of zoonotic pathogens, generally reflect their peculiarly pr olonged pattern of feeding. The metastriate ticks, including Dermacentor, A mblyomma, and Rhipicephalus, invariably attain sexual maturity and mate sol ely on their hosts. The more primitive prostriate Ixodes ticks, however, ma y copulate both in the absence of hosts and while the female engorges. Thes e expanded opportunities for insemination complicate the mating systems of the Ixodes ricinus complex of species. In these ticks, autogenous spermatog enesis must precede host contact, whereas anautogenous oogenesis requires t hat the females store sperm. All hard tick males undergo a courting ritual before they can deposit their spermatophores within the female's genital tr act. These diverse acid prolonged patterns of sexual interaction provide op portunities for interactions between populations and individuals that may b e relevant to the role of ticks as vectors of zoonotic pathogens.