Diasemiopsis ramburialis is a moth of the family Crambidae.

It occurs in most of Europe and the tropics, including the Azores, Fiji, New Zealand and Australia.

It is scarce migrant in Britain.

[2][3] This species was first described by Philogène Auguste Joseph Duponchel in 1834 and originally named Hydrocampa ramburialis.

[4] The larvae have been shown to feed on the water fern species Azolla filiculoides.