Orthobrachia tenebrosa Yazaki, 1992

Huang, Guo-Hua, Su, Zi-You & Stuening, Dieter, 2016, Taxonomic notes on the genus Orthobrachia Warren, with description of a new species from China and Thailand (Lepidoptera, Geometridae), ZooKeys 609, pp. 121-137 : 128-129

Taxon classification Animalia Lepidoptera Geometridae

Orthobrachia tenebrosa Yazaki, 1992 Figures 3A, 4C, 5C

Orthobrachia tenebrosa Yazaki, 1992, Tinea, 13 (Suppl. 2): 23. Type locality: Gandaki Parbat District, Nepal.

Diagnosis.

This species is similar to Orthobrachia latifasciata , Orthobrachia flavidior and Orthobrachia owadai , especially similar to latifasciata , which has very similar transverse lines and also a large, dark brown apical patch in the hindwing, but can be distinguished easily from all three species by the dark brown medial area of the hindwing which are white or greyish-white in the other three. Moreover, the postmedian line is situated more distally. In the forewing, the broader median area is more strongly suffused with greyish-brown (see also key to species). In the male genitalia, length and width of the uncus are intermediate between latifasciata and flavidior . The valva bears a small triangular, apically rounded costal process arising from beyond the middle, and the saccular lobe is longer, extending more dorsally beyond dorsal margin of the valva, compared to flavidior . The aedeagus is more slenderly built and shorter, two cornuti are present on vesica, but smaller in size. There is no external bunch of spines like in owadai . The female genitalia are very similar to those of latifasciata , but the antrum is smaller, with the lateral pair of spines of equal length of the central one. In latifasciata , the lateral spines are longer.

Material examined.

NEPAL: 1♂, Holotype, Gandaki Parbat District, Ghorapani, Deolari, 2800 m, 15.X.1981, M. Owada leg., NSMT; Paratypes, 5♂♂, Same data as holotype. INDIA: 1♀, Western Bengal, Tiger Hill, 2573 m, 30.IX-5.X.1986, F. Aulombard & J. Plante leg., BMNH.

Biology.

The adults are flying in September and October in high elevations between 2500 and 2800 m.

Distribution.

Nepal, NE. India

Remarks.

The female from Sikkim, designated as paratype by Yazaki (1992), is the only female known so far. We figure its genitalia here, provided by Mr. K. Yazaki.