[Ultrastructure of the antennal sensillae of the bug, Rhodnius prolixus (Hemiptera, Reduviidae)].

On the antenna of the bug R. prolixus we found numerous receptors which can be classified into three categories: mechanoreceptors (sensilla chaetica), olfactory (sensillae trichodea, basiconica and caeloconica) and gustatory (sensilla trichodea) receptors. The number, size and distribution on the antenna of each type have been recorded. A description of each of these sense organs is given. Tactile hairs are present on all of the antennal segments while thin-walled chemoreceptors are limited to segments 3 and 4. The tactile hairs are innervated by a single bipolar sensory cells. In fine structure each dendrite reveals the following successive regions; a broad inner segment, a ciliary region, a region with neurotubules. Two types of thin-walled sensilla trichoidae differ in the structure of the walls and internal parts. It was shown that the cuticular part of the olfactory trichoid hairs has pores; the cuticular part of the basiconic sensillae had longitudinal canals.