Halmus coelestris is a species of lady beetle in the family Coccinellidae and the genus Halmus. It is widely distributed Australia and New Guinea. Its main food source is a variety of small insects including but not limited to scale insects, psyllids, whitefly and free living gall mites (Eriophyoidea).
Halmus coelestris is approximately 2.5 to 3.9â¯mm in length. it has a metallic bluish or greenish smooth dorsal surface. the presence of a straight anterior border on the clypeus distinguishes H. coelestris from others in its genus.