Thyrocopa decipiens is a moth of the Xyloryctidae family. It is endemic to the Hawaiian islands of Oahu, Molokai, Maui and Hawaii. The length of the forewings is 16–23 mm. Adults are on wing year-round. The larvae feed on Freycinetia arborea. The larvae feed in the tips of branches, eating the leaves of the unexpanded spindle. There may be a dozen or more feeding somewhat gregariously.