Metathrinca tsugensis is a moth of the Xyloryctidae family. It is native to Japan, but is an introduced species in western Europe and Hawaii. The wingspan is 16–24 mm. The forewings are shining white, marked with fuscous as follows: over the upper vein of the cell, from just beyond the base to the end of the cell and continuing over vein 6 with branches 7 and 8, with a faint scattering of dark scales over 10 and 11. The lower vein of the cell, from the middle, is heavily overlaid with the dark colour, spreading over veins 2 to 5, the interspaces being more or less white, vein 1b from beyond the base to tornus. The extreme base of the wing is pure white, except the costa, narrowly edged with fuscous to the inner one-third. A dark subterminal line begins at the outer sixth of the costa, and