Similiar species:

Sixty two known species of Idaea Treitschke, 1825 from India (Kirti et al. 2019).
Idaea egenaria is a similar extralimital species. See at
https://www.mothsofborneo.com/part-10/sterrhini/sterrhini_1_17.php
Idaea gemmataria Hampson from Sri Lanka has a similar facies.

List of Idaea Treitschke, 1825 known from India based on Kirti et al. (2019).
Idaea actiosaria (Walker, 1861). Sri Lanka; India: Sikkim, Nilgiris.
Idaea acuminata (Moore, 1888). India: Darjeeling, West Bengal.
Idaea aequisinuata (Warren, 1898). India: Khasi Hills, Meghalaya.
Idaea amplipennis (Butler, 1889).
Idaea ajmerensis Wiltshire, 1983. India: Ajmere, Rajasthan.
Idaea andamanica Prout, 1938. India: South Andaman, Mt Harriet, Andamans Islands.
Idaea bilinea (Swinhoe, 1886). India: Pune, Maharashtra.
Idaea burspinosa Walia, 2004. India: Chandigarh.
Idaea carpheraria (Hampson, 1903). India: Chamba, Kashmir.
Idaea castelli pertensa (Prout, 1938). India: Sikkim.
Idaea charidotes (Prout, 1922). India: Assam, Khasi Hills, Meghalaya.
Idaea chotaria (Swinhoe, 1886).
Idaea chrysocilia (Hampson, 1891). India: Nilgiri district, the plateau, 6700ft.
Idaea conioptera (Hampson, 1903). India: Kuijar, Kashmir.
Idaea contiguaria contiguaria (Hubner, [1799]). India: Indian Himalayas.
Idaea costiguttata Warren, 1896).
Idaea craspedota (Prout, 1934).
Idaea decidua (Warren, 1900). India (North–West): Sabathu
Idaea delibata (Prout, 1926). India: Srinagar, 5200ft., Kashmir.
Idaea delicatula (Warren, 1901). India (North–West): Dalhousie, Himachal Pradesh.
Idaea dilutaria dilutaria (Hübner, [1799]). India: NW Himalayas, Sikkim.
Idaea falcipennis Warren, 1893. India: Sikkim.
Idaea flavisinuata (Warren, 1896). India: Khasi Hills, Meghalaya.
Idaea fuscifasciata Walia, 1995. India: Chandigarh.
Idaea fuscolineata Walia, 1995, India: Solan, Himachal Pradesh.
Idaea gemmaria (Hampson, 1896).
Idaea grisescens (Warren, 1896). India: Khasi Hills, Meghalaya.
Idaea humeraria (Walker, 1863). India.
Idaea improvisa (Prout, 1938). India: Khasi Hills, Meghalaya.
Idaea inaudax (Prout, 1926). India: Kumaon, Mukteshwar, 7000ft.Uttarakhand.
Idaea indecorata (Warren, 1900). India (North-West): Shimla, Himachal Pradesh.
Idaea indeprensa (Prout, 1925). India: Darjeeling, West Bengal.
Idaea indeterminata (Warren, 1901). India: Shimla, Himachal Pradesh.
Idaea informis Warren, 1897).
Idaea infortunata (Prout, 1938). India: Gurais Valley, Kashmir.
Idaea insuavis Butler, 1889. India: Kangra district, Dharamsala, Himachal Pradesh.
Idaea lacteipennis (Butler, 1889). India: Kangra district, Dharamsala, Himachal Pradesh.
Idaea leucozona (Hampson, 1893).
Idaea leucozona luteata (Warren, 1896). India: Khasi Hills, Meghalaya.
Idaea lineata (Hampson, 1893).
Idaea macrospila (Prout, 1926).
Idaea maculata (Warren, 1896). India: Khasi Hills, Meghalaya.
Idaea marcidaria (Walker, 1861).
Idaea marmorata (Hampson, 1903). India: Kadapa, Jammalamaduga, Andhra Pradesh,
Idaea mesodela (Prout, 1926). India: Srinagar, 5200ft. Gandarbal, Kashmir.
Idaea methaemaria (Hampson, 1903). India: Sikkim, 2800ft.
Idaea muricata muricata (Hufnagel, [1767]). India: Indian Himalaya.
Idaea micra (Hampson, 1893).
Idaea obliquilinea (Warren, 1896). India: Khasi Hills, Meghalaya.
Idaea onchnophora (Prout, 1939). India: Pusa, Bihar.
Idaea opsitelea monodia (Prout, 1938).
Idaea palniensis (Prout, 1920). India: Palni Hills.
Idaea perpulverea (Hampson, 1903). India: Gurais Valley, Kashmir.
Idaea persimilis (Warren, 1896). India: Khasi Hills, Meghalaya.
Idaea phoenicoptera (Hampson, 1896).
Idaea profanaria (Walker, 1866). India: South India.
Idaea protensa (Butler, 1889). India: Kangara district, Dharamsala, Himachal Pradesh.
Idaea ptyonopoda (Hampson, 1895). Bhutan; India: NE Himalaya.
Idaea pulchrifascia (Hampson, 1903). India: Sikkim, 1800ft.
Idaea purpurea (Hampson, 1891).
Idaea rubellata (Warren, 1896). India: Khasi Hills, Meghalaya.
Idaea rubridentata (Warren, 1896). India: Khasi Hills, Meghalaya.
Idaea ruptifascia (Warren, 1896). India: Khasi Hills, Meghalaya.
Idaea sabulosa (Prout, 1913). India: Dras, Kashmir.
Idaea scelisca (Prout, 1926). India: Kumaon, Mukteshwar, 7000ft., Uttarakhand.
Idaea semilinea (Warren, 1896). India: Khasi Hills, Meghalaya.
Idaea semisericea (Warren, 1897). India: Khasi Hills, Meghalaya.
Idaea sillemi (Wehrli, 1933). Kashmir: India: Karakoram, Nubra Valley, Panamik, 3350ft.Kashmir.
Idaea testacea Swinhoe, 1886. India: Pune, Maharashtra.
Idaea thricophora (Hampson, 1895).
Idaea triangularis (Hampson, 1895).
Idaea vacillata (Walker, 1862).
Idaea violacea (Hampson, 1891).