Idaea gemmaria

References :-
1. [187] Species 2000, http://www.sp2000.org
2. https://www.biodiversitylibrary.org/item/251778#page/361/mode/1up

Notes:
From Inaturalist :-
http://www.mothsofborneo.com/part-10/sterrhini/sterrhini_1_17.php :

Diagnosis. The broad purple grey and red bands on the wings, that of the hindwing broader, are diagnostic. See I. violacea above.

Taxonomic notes. The facies is very similar to that of I. gemmataria Hampson (Sri Lanka), but the genitalia of the latter, though sharing the acute saccus, have shorter valves and a shorter, broader, less rod-like cornutus in the aedeagus vesica. The second sternite is unmodified.

Geographical range. Borneo, Taiwan, Peninsular Malaysia (FRIM colln), Philippines, Sulawesi, Seram.

Habitat preference. The only specimen taken in recent surveys was from disturbed lowland forest near water tanks by the Sungei Burong, Lamunin, Brunei.

http://www.mothsofborneo.com/part10/sterrhini/sterrhini_1_17.php
highlighting similarity of I. egenaria with "Idea gemmataria" of Sri Lanka, but I believe that this item is the result of a transcription error of the species "Idaea gemmaria" described by the same author (Hampson) in Sri Lanka. Drawing of the same and description are present in "The Macrolepidoptera of the World" of A.Seitz- Stuttgart 1920:
https://www.biodiversitylibrary.org/item/251778#page/361/mode/1up
(Plate 12 f1) (in the same plate, last bottom right drawing by I. egenaria). On page 230 a brief diagnosis.