Lethe gregoryi Watkins 1927, stat. nov.

Lethe gregoryi Watkins, 1927 stat. nov.

(Figs. 1–6, 9, 10)

Lethe (Magula) helle gregoryi Watkins, 1927. The Annals and Magazine of Natural History (9) 19: 323. Type locality: Yangtze Valley, E. of Janula, Yunnan.

Lethe helle var. Gregoryi: Gaede in Strand, 1931. Lepidopterorum Catalogus 43: 295.

Lethe helle gregoryi: Bozano, 1999. Guide to the Butterflies of the Palearctic Region, Satyridae 1: 48.

Lethe moelleri bitaensis Yoshino, 1999. Neo Lepidoptera 4: 7, f. 49-50. Type locality: Zhongdian, NW Yunnan. syn. nov.

Lethe helle: Bozano, 2015. Revue des Lépidoptéristes de France 23 (58): 3, fig. 4.

Materials examined. Photo, ♂, Type / SYN-TYPE/ SYNTYPE Lethe (Magula) helle s.sp. gregoryi Watkins. det. P. Ackery 1972/ Yangtse Kiang Valley E. of Janula. 14. 000 24.vii.1922 / S. W. China: Yunnan. Prof. J. W. Gregory. B.M. 1923—114. (NHML); Photo, ♂, Holotype Yoshino coll./ Lethe moelleri bitaensis 1999 Neo Lepidoptera vol. 4/ 1996.8.2, Zhongdian County, Wengshui, Yunnan province [in Chinese]/ B1-624301 (MNHAH).

Specimens: 12 ♂♂, CHINA: Yunnan, Deqen, Dongzhulin, 12.VII.2012, leg. S-y. Lang (LSY); 2 ♂♂, CHINA: Yunnan, Shangri-la (formerly Zhongdian), Tuguancun, 21.VI.2014, leg. Hao Huang (LSY).

Notes. Both Lethe helle gregoryi and L. moelleri bitaensis were described from Jinshajiang valley, N. Yunnan, and no differences could be found between them. After checking the photographs of the type materials and examining a series of specimens from Jinshajiang valley, it is no doubt that Lethe gregoryi is a bona species and Lethe moelleri bitaensis is sunk as a junior synonym of L. gregoryi. It is worth noting that the holotype of bitaensis is collected in June 1995 according to the original description of Yoshino (1999), which is not consistent with the data on the label (August 2nd 1996). The mistake may have been made when the author donated the type to MNHAH. The nominotypical Lethe gregoryi is now known from Jinshajiang valley and Lancang valley (Bozano, 2015) in N. Yunnan.

Diagnosis. Lethe gregoryi can easily be distinguished from L. helle (Fig. 16) by the combination of the following characters: 1. Ground color of the dorsal side is dull brown, whereas it is reddish brown in L. helle; 2. Dorsal forewing, subapical white spots in spaces 3, 4 and 5 are distinct, whereas they are absent in L. helle; 3. Ventral hindwing, purple basal line is always obscure and less wavy, whereas it is a clear wavy line in L. helle.

Lethe gregoryi can be distinguished from the closely related species L. moelleri (Figs. 15, 31B) by the combination of the following characters: 1. Dorsal forewing, pale postdiscal spots are more distinguishable than those of L. moelleri; 2. Ventral hindwing, pale markings are more or less tinged with purple, whereas they are pure white in L. moelleri; 3. Ventral hindwing, pale discal band is bent inwards, whereas it is almost straight in L. moelleri; 4. Ventral hindwing, subbasal line is usually narrower and purple or whitish purple in color, whereas it is a coarse whitish line in L. moelleri.

Male genitalia (figs. 17–28): No obvious differences can be found among Lethe gregoryi, L. moelleri and L. helle, which reveals the close relationship of the three species. The caudal half of the aedeagus is laterally narrower in width in L. gregoryi and L. moelleri, whereas it is as wide as the cephalic half of the aedeagus in L. helle; The tegumen of L. gregoryi is more strongly humped than those of L. moelleri and L. helle.

Distribution. China (N. Yunnan).