Biston melacron Wehrli, 1941

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 : 50-52

Biston melacron Wehrli, 1941 Figs 4-67097

Biston melacron Wehrli, 1941, in Seitz, Gross-Schmett. Erde, 4 (Suppl.): 430, pl. 35: h. Syntypes 3♂, China: West Tien-Mu-shan, 1600 m. (ZFMK)

Biston exotica Inoue, 1977, Bull. Fac. domestic Sci., Otsuma Woman‘s Univ., 13: 322, figs 65-67. Holotype ♂, Japan: Kochi Prefecture, Kubokawa. (BMNH) (Synonymized by Heppner and Inoue (1992))

Diagnosis.

The external characters of this species are close to those of Biston marginata as follows: the male antennae are partially bipectinate and filiform at tip; the for ewing postmedial line bilobedly protrudes between M1 and M3, and slightly protrudes outwards between CuA2 and 1A + 2A. But it can be distinguished from Biston marginata by the following characters: the hindwing outer margin is concave between M1 and M 3, whereas it is evenly round in Biston marginata ; the transverse lines are black but dark brown in Biston marginata ; the hindwing postmedial line is waved after M3, but straight in Biston marginata ; the transverse lines on the underside of the wings are more conspicuous. The most distinct differences are in the male genitalia: the apex of the uncus is broader and bifurcated, whereas it is narrower and round in Biston marginata ; the median process of the gnathos is broader and round terminally, while in Biston marginata , it is slenderer and acute apically; the setose area of the valva is much weaker; the juxta is narrower, and sharply pointed apically, while in Biston marginata , it is broader and round apically; the cornutus is shortly digitiform, but is thornlike in Biston marginata . In the female genitalia ( Inoue 1977), the signum is much longer than in Biston marginata .

Material examineds.

CHINA, Chekiang [Zhejiang] (ZFMK): West Tien-Mu-shan, 1600 m, 27-29.IV.1932, coll. H. Höne, 3♂ (Syntypes); same data, 25.IV.1932, 1♂; same data, 25.V.1932, 1♂; same locality, 400 m, IV.1936, 1♂. Fukien [Fujian] (ZFMK):Kuatun, 2300 m, 3-7.IV.1938, 11.IV.1946, coll. J. Klapperich, 1♂. Formosa [Taiwan] (ZFMK): Puli, IV.1958, coll. ZSM, 1♂. Sichuan (IZCAS): Mt. Emei, Qingyinge, 800-1000 m, 17. IV– 1.V.1957, coll. Zhu Fuxing & Huang Keren, 8♂.

Distribution.

China (Zhejiang, Jiangxi, Fujian, Taiwan, Sichuan), Japan, South Korea.