The New World microgastrine braconid wasp genus Venanus is reviewed, and a new illustrated key to species is provided. Three new species are described and illustrated: Venanus kusikuyllurae Rasmussen & Whitfield, n. sp., reared from the gelechiid pests of quinoa (Chenopodium quinoa Willdenow), Eurysacca quinoae Povolný, and Eurysacca melanocampta (Meyrick) in Peru; Venanus greeneyi Whitfield & Arias-Penna n. sp., reared from pyralid caterpillars feeding on Phenax rugosus (Poir.) and Boehmeria spp. (both Urticaceae) in Ecuador; and Venanus yanayacuensis Arias-Penna & Whitfield, n. sp., reared from pyralid caterpillars feeding on several species of Asteraceae in Ecuador. In addition, the female of Venanus helavai Mason, previously known only from males, is diagnosed and illustrated, and we provide the first known host record for this species: pyralid caterpillars on Myrsine coriacea (Sw.) (Myrsinaceae).