Abstract: The type, number, and distribution of antennal sensilla of the two longicorn beetles, Saperda populnea and Saperda balsamifera were studied by using scanning electron microscopy. Results showed that the antennae in both male and female had three types of sensilla chaetica, one type of sensilla trichodea, three types of sensilla basiconica, and Böhm bristles. Sensilla chaetica were long sickle-shaped strong bristles with longitudinal grooves without pores on the cuticular wall; Sensilla trichodea were blunt-tapered hair with longitudinal grooves. They were inserted into a flexible socket without pores on the cuticular wall; Sensilla basiconica were oriented perpendicularly to the antennal surface. The cuticular wall of sensilla basiconica was perfored by irregularly distributed pores along its length; Böhm bristles were straight pegs with a sharp tip. Sensilla chaetica, sensilla trichodea and sensilla basiconica were common types of sensilla found in other species of the longicorn beetles. However, sensilla auricillica, sensilla campaniformia and sensilla finger were not found in this study. The likely functions of these sensillar also were discussed with reference to their morphology, distribution, and ultrastructure.

Key words: Saperda populnea, Saperda balsamifera, antennal sensilla, scanning electron microscopy