Metallarcha zygosema is a moth in the family Crambidae. It was described by Oswald Bertram Lower in 1897. It is found in Australia,[1] where it has been recorded from Western Australia[2] and South Australia.
The wingspan is about 20 mm. The forewings are light brown, with pale yellow markings outlined with darker brown. There is a large irregular cuneiform (wedge-shaped) patch from the base below the costa, its lower edge emitting a long slender streak along the inner margin to the anal angle. There is also a large irregular lunate mark in the middle of the wing, connected with the basal patch anteriorly by a short bar. The hindmarginal line is narrow and yellowish. The hindwings are pale fuscous, with a pale yellow basal patch.[3]
