Hemaris diffinis
A very variable species in colour and size, varying geographically, seasonally and individually. Legs more or less extended black inner spurs of mid- and hindtibiae comparatively shorter than in Hemaris tityus. Forewing with transparent discal cell not divided longitudinally by a scaled fold.
Male genitalia: Uncus and gnathos essentially as in Hemaris thysbe; gnathos always asymmetrical, often emarginate on the right. Juxta truncate. Valves not very asymmetrical, the right generally more slender. Left harpe ending in a short process bearing some setae; proximal of which is a curved, somewhat semi-lunar hump densely beset with minute setae; right harpe similar but process about twice as long as the left, often clubbed, with long setae apically. Phallus process simple, pointed.
Female genitalia: Antrum heavily sclerotized. Signum absent.