currently, E. cyclota is only known from China (see Fauna Sinica Insecta volumes..., Fang, 2000). I would be inclined to refer to the Malay Eugoa as sp. cf. cyclota until such time as voucher material has been dissected. It is not beyond the realms of impossibility that the one in your photo is cyclota, or a new species.
cheers,
Roger.
Roger C. KENDRICK Ph.D.
C & R Wildlife, Lam Tsuen, Tai Po, N.T., Hong Kong S.A.R.
HK Moths website: http://www.hkmoths.com
HK Moths Recording Project on i-Naturalist: http://www.inaturalist.org/projects/hong-kong-moths
HK Moths Flickr site: http://www.flickr.com/groups/hongkongmoths/