Pantaleonius .

Size: Body moderately small, delicate; forewing length 12.0– 13.1 mm; males and females of similar size, but with sexual dimorphism in abdominal markings (see below in this paragraph). Coloration: Head and thoracic markings in linear pattern not spotty; prothorax and dorsum of head with pair of dark, longitudinal stripes that extend onto dorsum of scapes; females, but not males, with abdominal sternites S4 and S5 dark brown to black; antennal flagellum mostly pale, with only basal ¼ to 1/5 black. Wings: Slender; forewing broad, ratio of length to width = 2.6: 1; costal area without splayed crossveins or dark markings; forewing and hindwing without dark patches. Tarsal claws: Basal dilation present, large. Abdomen: Setae relatively long, moderate density. Male: Dorsal apodeme of T9+e straight, with ventral spur; S8+9 fused, with suture present, not conspicuous; sparse microtholi present on S8 and distally on S7; gonarcus without gonocornu or frontal plate, with mediuncus winged, bearing one or two pairs of frontal setae; parameres absent. Female: Abdominal tergites without mesal suture; dorsum of T9+e without deep mesal invagination; praegenitale present, transversely elongate.

In summary, Pantaleonius is the only genus among the New World Belonopterygini to have a yellow to tan body with prominent (but not large) dark spots; wings without markings or splayed venation, but with dark veins; terminal segments of male abdomen with dorsal apodeme having a ventral spur that articulates with a robust, somewhat sclerotized membrane extending from the ventral spur of the dorsal apodeme to the dorsum of the mediuncus. In addition, the male has a broad, U-shaped gonarcus, winged mediuncus, and no parameres. In the female, a praegenitale is present; the subgenitale is elongate; and the spermatheca is tubular, bent with a large velum.