Diatraea evanescens is a moth in the Crambidae family. It was described by Dyar in 1917. It is found in North America, where it has been recorded from Alabama, Arkansas, Florida, Georgia, Louisiana, Maryland, Mississippi, North Carolina, Ohio, Oklahoma, South Carolina, Tennessee and Texas. The wingspan is about 18-20 mm. Adults have been recorded on wing from March to September. The larvae feed on Paspalum larranagae.