Sense organs in post-embryonic stages of Hyalomma marginatum marginatum Koch, 1844 (Acari: Ixodida: Ixodidae). II. Palpal organ.

Light microscopy and scanning electron microscopy (SEM) studies show the differences in structure, number and topography of terminal setae in the palpal organ in different stages of Hyalomma marginatum marginatum Koch, 1844. The palpal organ contains eight terminal setae in larvae and nymphs, and ten setae in adults. The length of these setae increases in the course of post-embryonic development. Other setae on palpal segments also undergo quantitative and morphological changes.