Blepharomastix dadalis is a species of moth in the family Crambidae. It was described by Herbert Druce in 1895. It is found in Costa Rica and Panama.[1]
The forewings and hindwings are silky white. The forewings with the costal margin, apex, and outer margin are shaded with dusky brown. There is a small spot in the cell and another at the end of it, as well as a submarginal pale brown waved line. The hindwings are crossed by a waved brown line below the middle and the apex is bordered with dusky brown.[2]