Mestolobes pyropa is a moth of the Crambidae family. It is endemic to Oahu and Molokai.The larvae feed on Peperornia species, including Peperomia pachyphylla. It is thought they mine the leaves of their host plant. Although the Peperomia leaves are thick, one leaf does not provide enough food for the caterpillar. After consuming all of the mesophyll of one leaf, the larva breaks through the epidermis and eats its way into another leaf to finish its growth, and a third leaf may also be attacked.