The nymph of Callibaetis dominguezi Gillies (Ephemeroptera: Baetidae)

Callibaetis dominguezi Gillies was described based on male and female imagines from the northwest of Argentina. Herein the nymph of this species is described for the first time. It can be distinguished from other species in the genus mainly by (1) distal margin of labrum with deep median emargination; (2) maxillary palp almost two times the length of galea-lacinia; (3) abdomen with segments I-X with a reddish brown spot along midline. Diagnoses for male and female imagines are emended after studying specimens reared from nymphs. In males the distal 1/3 of the forewings is pigmented while in females the costal and subcostal areas are brown; this character is unique for this species. © 2014 Taylor & Francis