Abrota is a monotypic butterfly genus in the family Nymphalidae. Its only species is Abrota ganga, the sergeant-major.
It is found in Sikkim, Bhutan, Abor Hills, Naga Hills, Burma, western China (Sichuan, Yunnan), Taiwan, Guangdong and Shanxi.
In 1932 William Harry Evans described the species as not rare.
The sergeant-major is 70 to 90 mm in wingspan.
The male sergeant-major is tawny with dark bands. The upper hindwing has four bands, of which the central two are well-separated in the wet-season form and nearly united in the dry-season form.
The female is dark brown with dusky tawny bands. The upper forewing has a streak in the cell with a spot beyond while the upper hindwing has two tawny bands.
Abrota ganga ganga (Bhutan, Sikkim, Assam, Burma, Metok)
Abrota ganga formosana Fruhstorfer, 1909 (Taiwan)
Abrota ganga flavina Mell, 1923 (China: Guangdong)
Abrota ganga pratti Leech, 1891 (western China: Sichuan, Yunnan)
Abrota ganga riubaensis Yoshino, 1997 (China: Shaanxi)