Keys to the Asclerobia species

Species of the genus Asclerobia are rather uniform in wing pattern; therefore, the superficial identification of species should be confirmed by other diagnostic characters: the genitalia of both sexes, the culcita of male abdomen (sternum VIII), structures of the head, and structure of the tympanal organ which, in the absence of sexual dimorphism, shows species specificity (figs 23–30).

Key based on external characters:

1. The ratio of the length to the width of the middle segments of male antenna is 1:2, the segments are noticeably wider (Figs 14–15)......................................................................................... sinensis

- The ratio of the length to the width of the middle segments of male antenna is 2:3, the segments are almost square (Fig. 13).. ................................................................................................... 2

2. Forewing: ante-medial line edged with grey-brown raised scales; the costa is same colour as the main background of the wing........................................................................................ alexandrae

- Forewing: ante-medial line with bright red-brown raised scales; the costa is noticeably lighter (white covered with grey-black scales).................................................................................... flavatinctella

Key based on male genitalia:

1. False cornutus trapezoidal (Fig. 18d)............................................................ flavatinctella

- False cornutus D- or C-shaped (Fig. 19d).................................................................. 2

2. Apex of the saccus truncate; the outer edge of the sacculus even......................................... alexandrae

- Saccus rounded apically; the outer edge of the sacculus slightly S-shaped crooked............................. sinensis

Key based on female genitalia:

1. Corpus bursae broadly egg-shaped (Figs 20a, 21a); ductus bursae departs from the “pole”.................. flavitinctella

- Corpus bursae elongated egg-shaped (Fig. 22a); ductus bursae departs from the same side as ductus seminalis............ 2

2. The length of VIII segment is 2.2× its width, corpus bursae as long as ductus bursae, papillae anales straight, longer.................................................................................................. alexandrae

- The length of VIII segment is 1.5× its width, corpus bursae as long as ductus bursae and antrum, papillae anales laterally have recess, shorter.................................................................................. sinensis