Borbo detecta, the rusty swift, is a butterfly of the family Hesperiidae. It is found from South Africa to eastern Africa and Zaire. In South Africa it is found in Eswatini and lowland riverine forests and savannah in KwaZulu-Natal to south-eastern Mpumalanga. The habitat consists of moist woodland.
The wingspan is 34âÂÂ36 mm for males and 36âÂÂ38 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.