Nematopogon Zeller, 1839

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 : 13

1. Nematopogon Zeller, 1839

Nematopogon Zeller, 1839: 185 . Type species: Nematopogon schwarziellus Zeller, 1839: 185 , by subsequent designation by Meyrick, 1912b: 2.

Nemophora Ḩbner, [1825] 1816: 417 (nom. praeocc.). Type species: Phalaena (Tinea) swammerdamella Linnaeus, 1758: 540 , by subsequent designation by Meyrick, 1912b: 2.

Diagnosis. The head is rough-haired on vertex; the face with appressed hairs. The Antennae are filiform, approximately 2–3 times the forewing length; the scape is stout, flagellums without spines. Labial palpi are short, extended forward, with sparse scales. The maxillary palpi are long, 5-segmented, filiform, folded. The hind tibiae had rough or appressed hairs. The forewing is elongated, and the ground color is simple, usually brownish to dark brown mixed with some black scales and small white spots, without blight luster. The hindwing is more or less clothed with hairscales. The R 3 and R 4 of the forewing are usually stalked, and M 1 and M 2 of the hindwing are usually stalked.

Remarks. The genus consists of 16 known species worldwide, of which only three have been recorded in China, including N. chalcophyllis ( Meyrick, 1935) (Zhejiang) , N. dorsiguttella ( Erschoff, 1877) (Northern China including Beijing), and N. taiwanella Kozlov, 2001 (Taiwan) . On the basis of three known species, we added a newly recorded species from China, namely N. distinctus Yasuda, 1957 .

Owing the very close external appearances of most Nematopogon species, there are usually only a few differences in the antennae (ring scales) and forewing (ground color, reticular markings, and white spots), which may be damaged by the lower quality of specimens or present a certain degree of intraspecific variations ( Bryner & Huemer 2019). Therefore, the diagnostic characteristics of male genitalia are particularly important and are necessary for species identification. The number of valvar pectinifer in the male genitalia is a very important distinguishing character or can be used as the basis for the identification of species groups in the genus. For example, there is only one valvar pectinifer in N. adansoniella , N. prolai , N. garganellus , and N. taiwanella , etc. ( Kozlov 2001; Bryner & Huemer 2019), and three in N. dorsiguttella , N. robertella , N. stenochlora , etc. ( Hirowatari & Hirano 1995; Karsholt & Kozlov 2011; Ji et al. 2018). In addition, some other characteristics can be used for species identification, such as the number of pegs in the valvar pectinifer, the shape and number of cornuti in the tip of the aedeagus. Kozlov (2001) suggested that N. taiwanella along with N. chalcophyllis and N. distinctus form a monophyletic group based on the presences of a flap of valva, large cornutus of aedeagus, and well-developed vestibulum. According to the light and dark ringed antennae, the close similarity of male genitalia and DNA barcodes analysis, Bryner & Huemer (2019) defined the N. adansoniella complex as including three closely related species, namely N. adansoniella , N. prolai , and N. garganellus . Previous studies have shown that the genus Nematopogon can also be divided into some species groups.

Key to species of the genus Nematopogon in China

1 Forewing with white spots at the central dorsum and subapical angle; valva with three pectinifer internally.. N. dorsiguttellus

- Forewing without white spot; valva with only one pectinifer internally........................................... 2

2 Tip of flap pointed; pectinifer with about 45 pegs; aedeagus apex with a pair of curved barb shaped cornuti dorsolaterally............................................................................................. N. distinctus

- Tip of flap rounded; pectinifer with fewer than 35 pegs; aedeagus apex without a pair of curved barb shaped cornuti....... 3

3 Pectinifer with fewer than 30 pegs; uncus with convex lateral margins; aedeagus with two cornuti; juxta with wide round arrow-head.................................................................................... N. chalcophyllis

- Pectinifer with 32–34 pegs; uncus with straight lateral margins; aedeagus with only one apical cornutus; juxta with pointed arrow-head................................................................................ N. taiwanella