Xylophanes chiron
General shape recalling a small Cechenena aegrota or Cechenena helops. Eyes large. Antenna feebly compressed; basal cilia of flagellomeres not distinctly prolonged.Ground colour of upperside of body and forewings deep green or brown; green specimens will turn brown on exposure to humid conditions but moths whose original coloration is brown are frequent, more so than green moths. Basal half of antenna dorsally white. Upperside of abdomen with an extremely faint median line flanked by two rows of dots. Spines along posterior edges of abdominal tergites very strong, uniseriate on last segments. Outer spur of midtibia as long as or longer than inner spur. Outer row of spines of forebasitarsus regular, single, with an additional spur on here and there. Midtarsal comb strongly developed. base of forewing with a small black patch that has a pale central; base of inner margin with a patch of primrose-yellow scales; transverse lines weakly developed; fourth postmedian line edged in pale brown, expanded at the apex into a small triangular patch and towards the inner margin (below M2) into a narrowly elongate triangular patch (conspicuous in the green forms, these pattern elements are difficult to distinguish from the ground colour in the brown forms); a dark brown patch on the inner margin basal to the fourth postmedial line. Ground colour of hindwing upperside dark brown or black; median band composed of a series of primrose yellow spots.
Male genitalia markedly different from all other species of Xylophanes. Tergite 8 rather deeply sinuate. Uncus broad, flat, deeply sinuate, the sinus rounded, the lobes feebly curved downward, slightly concave beneath; apex rounded. Gnathos compressed basally, apically dilated, truncate-sinuate, the angles rounded, with upper side concave. Harpe rather widened dorsad, upper edge angulate, compressed, feebly curved, apically rounded, mostly armed with a tooth, upper margin more-or-less notched. Dorsal margin of phallus abruptly ending on the right side in a comb of three to seven teeth; a regular row of long, sharply pointed teeth in a comb parallel to the edge, extending from near the comb to the left side; these teeth, except for the two small proximal ones, are essentially identical to the teeth found in the Cechenena aegrota group, being highly deciduous, becoming detached very easily.
Female genitalia: Sterigma more strongly sclerotized than is usual in Xylophanes; proximal edge of ostium bursae more prominent.