Delfinoia, a new South American aphid genus (Hemiptera, Aphididae, Macrosiphini) on Cayaponia (Cucurbitaceae).

The genus Delfinoia Nieto Nafría & Mier Durante gen. n. is established, and Utamphorophora peruviana (Essig), originally Amphorophora peruviana and currently Delfinoia peruvianacomb. n., is designated species type of the genus. The synonymy between this species and Wahlgreniella australis Delfino syn. n. is established. Apterous and alate viviparous females of D. peruviana are redescribed; the male is also described. The species is currently known from Peru and Argentina; a plant of the genus Cayaponia (Cucurbitaceae) is the only identified host.