Prenesta rubralis is a moth in the family Crambidae described by George Hampson in 1898. It is found in Peru[1] and Ecuador.[2]
The wingspan is about 34 mm. Adults are dark red, the forewings with traces of an antemedial line preceded by a yellowish mark in the cell. There is a distinct black-edged orange quadrate spot in the end of the cell, as well as a discoidal black lunule. The postmedial line has an orange spot on the outer side. The hindwings have a discoidal annulate spot and a curved fuscous postmedial line. Both wings have a terminal series of black points.[3]