51. Megacyllene castroi (Prosen, 1947)

Cyllene Mellyi Castroi Prosen, 1947: 255

Lectotype male: Argentina, Santiago del Estero: Villa Unión, III–IV.1944, Mario A. Castro (MNRJ). The specimen is herein designated as the lectotype in order to stabilize the taxonomy and facilitate further identification of this species.