Biston falcata (Warren, 1893)

Jiang, Nan, Xue, Dayong & Han, Hongxiang, 2011, A review of Biston Leach, 1815 (Lepidoptera, Geometridae, Ennominae) from China, with description of one new species, ZooKeys 139, pp. 45-96 : 68-69

Biston falcata (Warren, 1893) Figs 46 –5384–88111–113125– 127

Eubyjodonta falcata Warren, 1893, Proc. zool. Soc. Lond., 1893 (2): 416. Syntypes ♂, India: Sikkim. (BMNH)

Biston falcata : Hampson, 1895, Fauna Br. India (Moths), 3: 246.

Biston emarginaria Leech, 1897, Ann. Mag. nat. Hist., (6) 19: 322, pl. 7, fig. 8. Holotype ♀, China: Sichuan, Pu-tsu-fong. (BMNH), syn. n.

Amphidasis erilda Oberthür, 1910, Études Lépid. comp., 4: 677, pl. 51, fig. 435. Holotype ♂, China: Yunnan, Tse-Kou. (ZFMK), syn. n.

Amphidasis clorinda Oberthür, 1910, Études Lépid. comp., 4: 677, pl. 51, fig. 434. Syntype(s), China (west): Tse-Kou, syn. n.

Biston falcata clorinda : Parsons et al., 1999, Geometrid Moths of the World, a Catalogue, 1: 86.

Biston falcata satura Wehrli, comb. n.

Diagnosis.

The diagnostic characters of the external mophology and the male genitalia can be seen in the preceding species. In the female genitalia, the species can be distinguished from other congeners by the following characters: the apophyses posteriores are short, about twice the length of apophyses anteriores; the ductus bursae is sclerotized and striated longitudinally, about one-third the length of corpus bursae; the corpus bursae is weakly sclerotized and striated posteriorly; the signum usually consists of two small separate sclerotized patches.

Material examineds.

CHINA, Yunnan (ZFMK): Tse-kou, coll. R. P. Dubernard, 1895, 1♀ (Holotype of Biston falcata clorinda ); Tse-kou, coll. R. P. Dubernard, 1900, 1♂(Holotype of Amphidasis erilda ); Shaanxi (ZFMK): Tapai-shan im Tsinling, Sued-Shensi, 25.VI.1935, coll. H. Höne, 1♂ (Holotype of Biston erilda satura ); Zhejiang (ZFMK):West-tien-mu-shan, 1♂; Sichuan (ZFMK): Chasseurs Indigènes de Ta-tsien-lou, Récolte de 1910,1♀; Sichuan (BMNH): Pu-tsu-fong,2993 m, VI–VII.1890, coll. Native, 1♀. (Holotype of Biston emarginaria ). Ningxia(IZCAS): Jingyuan, 2052-2084 m, 29.VI.-2.VII.2008, coll. Sun Wenhui, 3♂; Longde, Sutai Linchang, 2165 m, 6.VII.2008, coll. Song Wenhui, 2♂. Gansu(IZCAS): Zhouqu, Shatan Linchang, 4-7.VII.1998, coll. Yao Jian et al., 17♂;Zhouqu, Shatan Linchang, 2400 m, 4-16.VII.1999, coll. Yao Jian et al., 17♂4♀;Wenxian, Baishuijiang, IX.1986, coll. Wang Hongjian, 1♂; Wenxian, Qiujiaba, 2350 m, 21-29.VII.1999, coll. Chen Jun et al., 9♂; Shalin, 2357 m, 25. VI– 28.VII.2002, coll. Cao Xiuwen, 2♂; Wushan, Tanyu, 26.VII.1990, coll. Deng Lianhai, 1♂; Kangxian, Qinghe Linchang, 1400 m, 8.VII.1999, coll. Zhu Chaodong, 1♀; Renmingchi, 2450 m, 30.VII.2002, 1♀; Baishuijiang, VII.1986, coll. Wang Hongjian, 1♀. Sichuan(IZCAS):Wenchuan, Wolong, 1920 m, 24-29.VII.1983, coll. Wang Shuyong et al., 4♂; Wenchuan, Wolong, 1900 m, 27.VIII.1982, coll. Chen Yuanqing, 1♀; Mt. Emei, Jiulaodong, 1800-1900 m, coll. Huang Keren, 2♂; Gonggashan, Yanzigou, 2350 m, 3.VI.1983, coll. Zhang Xuezhong, 1♂; Luding, Moxi, Hailuogou, 2821-3155 m, 15-17.V.2009, coll. Li Jing, 2♂. Yunnan(IZCAS): Lijiang, Yulongshan, 2700-2800 m, 27.VII.1984, coll. Chen Yixin and Liu Dayun, 3♂; Lijiang, Yulongshan, 2680-3296 m, 15-23.VI.2009, coll. Han Hongxiang et al., 18♂; Jizushan, 2500 m, 30.VI.1980, 1♂; Yiliang, 200 m, 13.VII.1979, 1♂; Yiliang, 20.VII.1982, coll. Wang Linyao, 1♂; Diqing, Xiaozhongdian, Linyechang, 3700 m, 28.VII.1979, coll. Yan Baiqun, 1♀; Xiaozhongdian, 3100 m, 30.VII.1984, coll. Liu Dayun, 1♂; Tengchong, 2500 m, 2-4.VI.1992, coll. Xue Dayong, 3♂. Tibet (IZCAS): Nyingchi, Pêlung, Mamba, 2115 m, 1-2.IX.2005, coll. Wang Xuejian, 1♂; Nyingchi, Bayi, 2999 m, 1-3.VIII.2006, coll. Lang Songyun, 2♂; Mainling, Pai, 2883 m, 4-6.VIII.2006, coll. Lang Songyun, 7♂; Bomi, Yi’ong, 2300-2750 m, 28-31.VIII.1983, coll. Han Yinheng and Lin Zai, 2♂; Bomi, Yi’ong, Tangmai, 2079 m, 29-30.VIII.2006, coll. Lang Songyun, 1♂; Mêdog, 1060-3213 m, 7-13.VIII.2006, coll. Lang Songyun, 3♂; Cona, Mama, 2900 m, 6.VIII.1974, coll. Huang Fusheng, 1♀; Nyalam, Zham, 2250 m, 9-20.V.1974, coll. Zhang Xuezhong, 3♂; Zham, Qu, 3300 m, 6-7.VII.1975, coll. Huang Fusheng and Wang Ziqing, 2♂; Gyirong, 2800-3300 m, 26. VII– 8.VIII.1975, coll. Wang Ziqing and Huang Fusheng, 3♂3♀; Gyirong, Gongshe, 28.VIII.1984, coll. Yan Zhaoxing, 1♂; Yadong, 2800 m, 23.VII.1960, coll. Wang Chunguang, 1♂; Yadong, 10.VIII.1982, coll. Wangjia Tsering, 2♂; Yadong, Linchang, 29.VIII.1984, Li Aihua, 1♀. Large series of material from Yunnan (ssp. falcata) and Shaanxi (ssp. satura Wehrli) in coll. ZFMK.

Distribution.

China (Shaanxi, Ningxia, Gansu, Zhejiang, Sichuan, Yunnan, Tibet), India, Nepal.

Remarks.

After examinating the types of Amphidasis erilda Oberthür, 1910, Amphidasis clorinda Oberthür, 1910, Biston emarginaria Leech, 1897, Biston erilda satura Wehrli, 1941 and a large series of material from China and the neighbouring regions it became obvious that Biston emarginaria (only females known) and Amphidasis clorinda (female holotype known only) are all females of Amphidasis erilda . The external and genital features of Amphidasis erilda , on the other hand, turned out to be almost identical or fall within the range of variation of Biston falcata . Thus we treat Biston emarginaria , Amphidasis erilda , Amphidasis clorinda as junior synonyms of Biston falcata . Biston erilda satura , as described by Wehrli (1941), is treated as a valid subspecies, but has be combined newly with Biston falcata , as explained above. Thus, two Chinese subspecies of Biston falcata are Biston falcata falcata (Warren, 1893) and Biston falcata satura (Wehrli, 1941). In China, the former is distributed in Sichuan, Yunnan and Tibet (Figs 46, 48-51, 84-86, 112, 125,126), the latter is distributed in Shaanxi, Ningxia and Gansu (Figs 47, 52, 53, 87, 88, 113, 127). There are some intraspecific variations between individuals of Biston falcata , for example, in the the male genitalia, the apical part of the valva varies from broad to narrow in the same region, such as Gansu (Figs 87, 88) and Tibet (Figs 85, 86); in the female genitalia, the signum usually consists of two small separate sclerotized patches, sometimes there is only one signum or the signum is very tiny, and the position of the signum is variable individually.