Abstract: [Objective] This study aims to understand the ultrastructural characteristics of the antennal surface of Atrjuglans hetaohei Yang moth which is a serious fruit pest on Chinese walnut, Juglans regia.[Method] The antenna, sensillum and scale structure of both male and female A. hetaohei adults were studied using a scanning electron microscope.[Result] The result showed that the antenna was filamentous comprising scape, pedicel and flagella. The flagellum consists of 45 and 51 segments in male and female, respectively. Nine types of sensilla on the surface of antennae were observed:sensilla trichodea, sensilla chaetica, sensilla auricillica, sensilla coeloconica, sensilla styloconica, sensilla squamiformia, Böhm bristles, sensilla basiconica and campullacea sensilla. sensilla trichodea, sensilla auricillica and sensilla coeloconica had two subtypes, i.e., sensilla trichodea I and sensilla trichodea Ⅱ, sensilla auricillica I and sensilla auricillica Ⅱ, sensilla coeloconica I and sensilla coeloconica Ⅱ. The distribution and quantity of each sensillum, however, were different in each segment of antenna. Sensilla were mainly borne on the ventral surface of antenna, long song trichoid sensilla and campullacea sensilla were only found on males. Böhm bristles were distributed on the base of male antenna, and they were significantly different in morphology between males and females. The scape and pedicel were covered with scales, whereas the dorsal and lateral sides of each flagellar segment, except for the last segment, were covered with scales. There were holes, ridges, ribs, microribs structures on the scales. The spacing of ridge, width of ridge, length of rib, length of microrib on each subsegment scales were greater in females than in males. Holes were mainly distributed in scape, pedicel and some base segments of flagellar. Holes could be divided into seven types:single hole, double holes, three holes, four holes, five holes, six holes and seven holes. The types and distributions of holes in the scales of different parts were different. The type of holes in scales of scape of female was richer than in male, however, in antennal pedicel and flagella the type of holes in scales of male was richer than those of female.[Conclusion] This study has described the ultrastructures and characteristics of the sensilla and the holes in the scales of the antenna of A. hetaohei, and its specific function should be studied in combination with electrophysiology, morphology and molecular biology.

Key words: Atirjuglans hetaohei, scanning electron microscope(SEM), antenna, sensilla, scale, hole