Studies on in vitro Extrusion and Ultrastructure of the Spermatophore in Haemaphysalis longicornis (Acari: Ixodidae)

Copulation in ticks is completed by the insertion of the spermatophore into the female genital aperture by a male. The endospermatophore, a cord‐like structure and contents are packed in the ectospermatophore of the completed spermatophore. The endospermatophore extrudes just after insertion of the tip of the spermatophore. Only the endospermatophore enters the female genital tract, and the ectospermatophore remains outside the female body. The extrusion is observed in vitro in Haemaphysalis longicornis at various concentrations of NaCl solution: the process is accelerated in less concentrated solutions. The cord‐like structure and the endospermatophore finally receive contents extruded from the ectospermatophore. The tip of the cord‐like structure connects to the surface of the endospermatophore, and together form a loop after extrusion. Ultrastructural observations confirmed that the ectospermatophore wall is composed of four layers, and the contents consist of male germ cells and three types of secretions from the male accessory genital glands. As in other ticks the male germ cells are elongated spermatids in spermatophores just after formation and extrusion. Adlerocysts described in other ticks are not found in the spermatophore of H. longicornis .