A fairly large (4.5-6.2 cm. wingspan) day-flying moth with narrow, pointed translucent wings. The wings have dark olive brown (forewing) or red brown (hindwing) bases, a wide dark outer margin, and the veins are lined with dark scales. The heavy body is covered in dark olive-brown hairs, except for a wide dark band on the abdomen. In Alberta, it can be mistaken only for the Snowberry Clearwing, which is smaller, has narrow dark outer margins on the wings, and large yellow patches on the sides of the lower abdomen. The very similar Slender Clearwing (H. gracilis) has been reported from eastern Saskatchewan and may eventually turn up in eastern Alberta. H. thysbe can always be told from other species of Hemaris by the row of dark scales bisecting the forewing discal cell (absent in other Hemaris species). Royal Alberta Museum page