Nemophora bifasciatella, Issikii, 1930

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 : 53-54

3.13 Nemophora bifasciatella species group

Nemophora mediseorsa group (Sun & Li 2023: 485)

Diagnosis. This species group is characterized by the following characters: the very small body size, wing expanse of 10–15 mm; the eyes are very small, widely separated dorsally, with eye size index of 0.44–0.58; the forewing has a pair of black-margined bluish-leaden transverse central fasciae, which are separated by a yellowish to the brown band; the basal part of the sacculus is almost completely fused; and the apical part of the aedeagus has a slender keel dorsally. In addition, unlike most other adelid moths, the basal part of the female antenna of this species group is prominently slender without densely raised thick scales.

Remarks. Nemophora bifasciatella Issiki, 1930 was originally described in Japan. Based on the examination of types deposited in NMNH (Washington) and other more specimens, Hirowatari (1995) redescribed N. bifasciatella with descriptions of two other new related species from Japan, namely N. sylvatica and N. stellata . Recently, Sun & Li (2023) described four new species, namely N. mediseorsa , N. longiuga , N. longissima , and N. mediangusa , and established the mediseorsa species group. We consider that at least N. bifasciatella and N. sylvatica are closely related to the species described by Sun & Li (2023) though they did not refert to this point. Therefore, in the present study, we treat these species as the bifasciatella group, because N. bifasciatella is the oldest species in this group. Recently, Kozlov (2023c) reported the distribution of N. mediseorsa in India and described a new species, namely N. manipurella , which obviously belongs to this species group. Here, we redescribe two species of them, N. longiuga and N. longissima , and roport N. bifasciatella from China for the first time.

Key to species of the bifasciatella group based on external morphology

1 Forewing without basal black speckle, outer fascia narrowed medially............................... .. N. mediangusa

- Forewing with basal black speckle, outer fascia separated medially.............................................. 2

2 A pair of bluish-leaden transverse central fasciae both consecutive, near X-shaped; apical yellow scales area nearly round or oval..................................................................................... N. bifasciatella

- The outer bluish-leaden transverse central fascia usually separated at middle, near K-shaped; apical yellow scales radial.... 3

3 Forewing distinctly slender, length/width ratio about 4.2; basal 1/5 of forewing with a slightly wavy white transverse line.. 4

- Forewing relatively short, length/width ratio about 3.6; basal 1/5 of forewing without white transverse line...... N. longiuga

4 Apical part of forewing with six yellow radial stripes............................................... N. mediseorsa

- Apical part of forewing with four yellow radial stripes.............................................. N. longissima

Key to species of the bifasciatella group based on male genitalia

1 Vinculum extremely long and slender, about 4.6 times as long as valva; aedeagus with a very long and slender keel dorsally extending from middle of aedeagus............................................................. N. longissima

- Vinculum moderate in length, 2.9–3.3 times as long as valva; aedeagus with a short keel at apical 1/6 dorsally........... 2

2 Costa of valva extending a nearly rectangular lobe basally; apex of aedeagus with many large spines dorsally.... N. longiuga

- Costa of valva without additional lobe basally; apex of aedeagus without distinct spines............................. 3

3 Phallus with hook-shaped process at distal 1/8; Vinculum distinctly short, about 2.2 × length of valva....... N. mediangusa Phallus without hook-shaped process at distal 1/8; vinculum relatively slender, more than 2.5 × length of valva........... 4

4 Phallus with a short rod at subbasal area of suprazonal sheath....................................... N. bifasciatella

- Phallus with belt of spines from near 2/5 to 1/9.................................................... N. mediseorsa