Gonad development and gametogenesis in Boophilus decoloratus (Koch, 1844) (Acarina Metastriata Ixodidae)

Abstract

Phases in the growth of the reproductive organs and gametogenesis were followed in both males and females of Boophilus decoloratus (Koch, 1844). Special attention was given to the timing of meiosis, the production of mature spermiophores, mating and spermiophore relocation in the female. The main growth phase of the male testes takes place during the nymphal stage while that of the accessory gland complex takes place during the 4 days after moulting and before mating. The main growth phase of female ovaries and oviducts takes place during the post-mating period on the host and the previposition period. Meiosis in males takes place only after the attachment of the newly-moulted ticks; spematogenesis and spermiogenesis occur within a period of 4 days, after which pairing and spermatophore transfer take place. Meiosis was not observed in female ticks and it is concluded that this reduction division takes place only after spermiophore penetration of the oocytes and egg shell formation. Female ticks may be impregnated more than once, a maximum of 5 matings being deduced from counts of spermiophore capsules in the female seminal receptacle. Each spermatophore produced by male ticks yields either 1 but more commonly 2 spermiophore capsules. The reproduction of B. decoloratus is briefly discussed and compared with other Ixodoidea.