Autogeny in the Tick Ornithodoros Tholozani (Ixodoidea, Argasidae)1

Abstract

Autogeny is described as a characteristic (but variable) feature in certain species of argasid ticks. In Ornithodoros tholozani, females which are relatively large at ecdysis are autogenous, and smaller ones are not. The smallest females did not attract males before feeding. A positive correlation was found between the weight of the female at ecdysis and the number of eggs in the first autogenous oviposition. The percentage egg hatch was variable but an average of 57% of eggs from autogenous females hatched compared with 85–90% from anautogenous females. The duration of the preoviposition period and its possible relationship to the development of oocytes arc discussed.