Nemophora askoldella (Milliere, 1879)

Liao, Cheng-Qing, Hirowatari, Toshiya, Yagi, Sadahisa, Wang, Min, Wang, Xing & Huang, Guo-Hua, 2023, The fauna of the family Adelidae (Insecta, Lepidoptera, Adeloidea) from China, Zootaxa 5348 (1), pp. 1-152 : 21-22

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