Insect mouthparts can be a useful addition to evolutionary research, especially when their structure and function are well understood. In the present study, the proboscis morphology and sensilla distribution in Tretopteryx pertusalis were investigated in order to further the understanding of the relationship between moth mouthparts and food selection. Sensillas showing different distributions on the tube surface were examined using scanning electron microscopy. The galeal surface of T. pertusalis, which has a relatively short proboscis, is in the form of a cuticular ridge bearing numerous microtrichia. There are 3 types of sensilla found on the proboscis. Sensilla chaetica is the most common type along the length of the proboscis of varying lengths. Sensilla basiconica is found on the surface of the galea and in the food canal. Sensilla styloconica is located only in the tip region.