Husky is probably right, though all the photos are of M. hyrtaca, just at different instars. These have been reared in Hong Kong (see the HKWildlife.net forum and search for Metanastria).
Don't think much of the "spray first ask questions later" approach - was there any sensible reasoning put forward to justify such action?
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/