Borbo detecta, the rusty swift, is a butterfly of the Hesperiidae family. It is found from South Africa to eastern Africa and Zaire. In South Africa it is found in Swaziland and lowland riverine forests and savannah in KwaZulu-Natal to south-eastern Mpumalanga. The habitat consists of moist woodland. The wingspan is 34–36 mm for males and 36–38 mm for females. Adults are on wing year round, but are scarcer in winter in southern Africa. The larvae feed on various Poaceae species, including Ehrharta erecta.