Grass Demon (Udaspes folus)

An uncommon butterfly probably occurs all over the island where its larval host plants available, excluding higher hills  . Both Ormiston (Ormiston  W., 1924)  and Woodhouse (Woodhouse L.G.O. , 1950) treated it as a very rare insect in Sri Lanka. However now a days it seems to be not such a rarity, probably due to adopting of its larva to feeds on varies exotic plants such as Curcuma longa[කහ/Turmeric], Curcuma zedoaria [හරන් කහ], Hedychium coronarium [එළ මල්], Kaempferia galanga [හිඟුරු පියලි], Alpinia calcarata (කලා කීරිය/කටු කීරිය/Indian Ginger/Snap-Ginger) and Zingiber officinale [ඉඟුරු/Ginger] some of them are widely cultivated. Curcuma oligantha is the only known larval food plant of it which is not introduced but indigenous (ibid).

References:

Ormiston  W., 1924 The Butterflies of Ceylon, H.W.Cave & Co., Colombo 1924, AES Reprint New Delhi, 2003

Woodhouse L.G.O. , 1950 The Butterfly Fauna of Ceylon, Ceylon Government Press, Colombo, 2nd (Abriged) Edition.  1950.