General Description

This is one of three species of Hemaris in Alberta which mimic bumblebees. The Slender Clearwing can be distinguished from H. diffinis by the much broader hindwing margin, and brown as opposed to black bands on the thorax underside. Two characters easily distinguish gracilis from thysbe: the forewing cell of thysbe is crossed by a line (a vein with dark scaling), whereas this cell is unmarked in H. gracilis. The underside of the abdomen is completely yellow in thysbe, whereas gracilis has two longitudinal red-brown bands.