Key to Trichopteryx carpinata and Trichopteryx ignorata

1. Moths larger on average, forewing length 14–17 mm; forewing with antemedial band weakly curved, approaching to costal edge at a right or at an acute angle (looking from the wing root); hindwing upper side with background almost white, much paler than the background of forewings; in males hindwings with vannal fold small, in length approximately as half as distance between base of wing and point of CuA1 arising from discal cell. The male genitalia with sacculus almost straight or gently arched, saccus moderate, rounded, in length much shorter than juxta. The female genitalia with anterior apophyses much longer than 8-th abdominal tergite, ductus bursae very long, approximately 3 times as long as corpus bursae, conic, antrum narrower.................................................................................. T. carpinata (Fig. 26).

- Moths smaller on average, forewing length 13–15 mm; forewing with antemedial band strongly curved, approaching to costal edge at a right or at an obtuse angle (looking from the wing root); hindwings upper side with background grey, almost equal in tone to background of forewings; in males hindwings with vannal fold larger, in length approximately as 2/3 as distance between the base of wing and point of CuA1 arising from discal cell. The male genitalia with sacculus hook-like distally, saccus large, conic, in length close to length of juxta. The female genitalia with anterior apophyses markedly shorter than 8-th abdominal tergite, ductus bursae moderately long, approximately 2 times as long as corpus bursae, with almost parallel lateral sides, antrum wider........................................................................... T. ignorata.