Archernis leucocosma is a moth in the family Crambidae.

The forewings are greyish-brown with a fine fuscous transverse line and a snow-white median discal spot, edged anteriorly with fuscous.

There is a fine fuscous wavy line from the costa to the dorsum, edged posteriorly with white in the costal portion.

The hindwings are greyish-brown with a snow-white discal spot edged anteriorly with fuscous.

There is also a fuscous postmedian line, edged posteriorly with white throughout.