Tropideucoila blepharoneurae, a new species of Zaeucoilini, is described from Peru. Specimens were reared from numerous species of the tephritid genus Blepharoneura feeding on species of Gurania (Cucurbitaceae). Prior to the discovery of this species, it was hypothesized that species of Tropideucoila were restricted to Agromyzidae hosts; this new species is remarkable for its host association with Tephritidae. To support the inclusion of this new species in Tropideucoila, we performed a total evidence phylogenetic reconstruction of the Zaeucoilini; this new species was recovered (with strong branch support) within Tropideucoila.