Mylothris rubricosta, the eastern swamp dotted border or streaked dotted border, is a butterfly in the family Pieridae.

It is found in Sudan, Ethiopia, Uganda, Rwanda, Burundi, the Democratic Republic of the Congo, Kenya, Tanzania, Malawi, Zambia, Mozambique, Botswana and Zimbabwe.

Adults have a weak flight and stay close to the ground.

Adults feed on the flower nectar of Persicaria barbata.

The larvae feed on Persicaria barbata species.