adult seta adult smooth double-walled sensilla Fig. 15-5, Fig. 15-8, Fig. 15-9, in Biology of Ticks ISBN:0-19-505910-7. Spoke-wheel sensilla TADS:0000577 TADS:0000577 These are setiform (i.e., hair-like) sensilla in which the walls contain very pores in faint grooves along the margins. The pores are normally only visible using the scanning or transmission electron microscope. These sensilla have a double wall. Examples are found in the anterior pit and posterior capsule of the Haller's organ. These sensilla are believed to function as chemosensory sensilla, but their precise role is uncertain. default_namespace