Syllepte acridentalis is a moth in the Crambidae family. It was described by Hampson in 1912. It is found in New Guinea.
The wingspan is about 32 mm. Adults are yellow, the forewings with a curved, somewhat waved and diffused antemedial line from the subcostal nervure to the inner margin. There is a dark point in the middle of the cell and a discoidal lunule. the postmedial line is strongly and rather irregularly dentate, oblique, bent outwards between veins 5 and 2 and with a diffused dentate band across its sinus. The hindwings have an oblique diffused somewhat dentate band from the costa beyond the middle to the tornus, towards which it narrows and with a dentate line beyond it between veins 5 and 2. The apical part of the costal area is suffused with brown.