N. tigrina has been confused with (e.g. Jia & Yu, 2018) (and placed as a junior synonym of, e.g. Beccaloni et al. (2003)) Orthospila orissusalis (Walker, 1859). The two are treated as separate species by Nuss et al. (2003-2017).
The placement of tigrina in Notarcha follows Nuss et al. (2003-2017), though it is noted the allied species definita Butler, 1889 is currently placed in Dichocrocis (as per Nuss et al.).

Jia, C.J. & Yu, T.T. (eds.), 2018. Moths of the Mt. Wutongshan. Hong Kong Lepidopterists’ Society, Tuen Mun, Hong Kong. iii + 303 pp.
Beccaloni, G.; Scoble, M.; Kitching, I.; Simonsen, T.; Robinson, G.; Pitkin, B.; Hine, A. & Lyal, C. (eds.), 2003. The Global Lepidoptera Names Index (LepIndex). http://www.nhm.ac.uk/our-science/data/lepindex/

1. Nuss, M.; Landry, B.; Mally, R.; Vegliante, F.; Tränkner, A.; Bauer, F.; Hayden, J.; Segerer, A.; Schouten, R.; Li, H.; Trofimova, T.; Solis, M. A.; De Prins, J. & Speidel, W., 2003–2017: Global Information System on Pyraloidea. www.pyraloidea.org