Bactra straminea is a moth of the Tortricidae family. It is only known from the Hawaiian islands of Kauai, Oahu, Molokai, Maui, Lanai and Hawaii, but might be an introduced species, although it has not been recorded from any other location. Adults are extraordinarily variable in color, pattern, size and even in genitalia. In some varieties there is constant and conspicuous sexual dimorphism. The larvae feed on Carex, Cladium angustifolium and Scirpus miritimus. They bore the stem of their host plant.