A description of the adult of a new species of Eupithecia Curtis, apparently endemic to the Pampa del Tamarugal, Chile, is presented. Its larvae are anthophagous on Prosopis tamarugo Phil. (Fabaceae). Adult, male abdominal segment VIII and male and female genitalia are illustrated.
Larentiinae; taxonomy; Eupithecia tamarugalis; Eupithecia sibylla; Eupithecia taracapa; Prosopis tamarugo