3.3 Nemophora askoldella species group

Nemophora askoldella group (Kozlov 1995: 461)

Diagnosis. The askoldella species group can be distinguished by the following features: the compound eyes are relatively large, eye size index is 0. 9– 1.1 in male and 0.6–0.7 in female; the proximal segments of the male antenna are dorsolaterally covered with dark brown or blackish scales; the female antenna has a characteristic brush on flagellar segments 18–23; the female antenna is 1.1–1.3 × length of the forewing; the background color of the forewing is gray, randomly mixed with dark and light scales, hindwing base white and translucent; the forewing lacks longitudinal stripes, but the base of radial stem has small dark spots; the head light color, usually white, gray, or silver-gray.

Remarks. This species group includes five species: N. griseella (Walsingham, 1880) (India, Nepal, Myanmar), N. ischnodesma (Meyrick, 1928) (India, Myanmar), N. cassiterites (Meyrick, 1907) (India), N. askoldella (Millière, 1879) (China, Russia, Japan, Korea), and N. chionites (Meyrick, 1907) (India, Thailand). Here, N. chionites is first reported in southern China.

Key to species of the askoldella group based on external morphology

1 Forewing transverse central fascia approximately equal in width; labial palpus relatively short, not exceeding vertical eye diameter................................................................................... N. askoldella

- Forewing transverse central fascia twice as wide at costa than at termen; labial palpus very long, about 2 × vertical eye diameter.................................................................................... N. chionites

Key to species of the askoldella group based on male genitalia

1 Vinculum relatively short, about 2.4 × as long as valva; lateral margin of valva nearly parallel to the central axis; suspensorium relatively short, slightly beyond posterior margin of vinculum......................................... N. askoldella

- Vinculum relatively long, about 2.6 × as long as valva; tip of valva distinctly oblique outwardly, lateral margin about 30-degree angle with the central axis; suspensorium long, far beyond posterior margin of vinculum..................... N. chionites