Cotesia urabae is a small wasp, having a black body with yellow-brown legs, characterized by a solitary larval endoparasitoid stage. It is part of a large complex of 11 primary parasitoids of Uraba lugens Walker, many of which are polyphagous. The female inserts its ovipositor into the a U. lugens larva, depositing its eggs there, and it has been found that one female may carry up to 400 eggs. While C. urabae females are able to attack the same larva several times; only one single parasitoid completes its development in each larva.