Metallarcha tetraplaca is a moth in the family Crambidae. It was described by Edward Meyrick in 1887. It is found in the Australian[1] state of Western Australia.[2]
The wingspan is about 22 mm. The forewings are clear yellow with light ashy-grey markings, margined with blackish. There is a streak along the costa from the base to four-fifths. The hindwings are fuscous grey, the costa suffusedly whitish ochreous, except on a bar before the middle and another almost apical. The apex and upper half of the hindmargin are narrowly and irregularly pale ochreous yellowish, sometimes continued further towards the anal angle.[3]