The nymph of Callibaetis dominguezi Gillies (Ephemeroptera: Baetidae)

Abstract

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.

Callibaetis dominguezi Gillies fue descripta a partir de machos y hembras del Noroeste de Argentina. Aquí la ninfa de esta especie se describe por primera vez. Se puede distinguir de las otras especies del género principalmente por (1) el margen distal del labro con una profunda emarginación media; (2) palpo maxilar casi dos veces el largo de la galea-lacinia; (3) abdomen con los segmentos I–X con una mancha castaña rojiza alargada en la línea media. Las diagnosis para los machos y las hembras adultas están mejoradas después de estudiar los especimenes criados a partir de las ninfas. En los machos el tercio distal de las alas anteriores está pigmentado mientras que en las hembras las áreas costal y subcostal son castañas, este carácter es único para esta especie.

Keywords:

• Argentina
• mayfly
• description
• taxonomy
• aquatic insects

Acknowledgments

We would like to thank Eduardo Domínguez and Carlos Molineri for the collection and rearing of the studied specimens; PVC is indebted to Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) –Protax processes number 52/2010 and Instituto Federal de Educação, Ciência e Tecnologia do Amazonas-IFAM, Campus Lábrea. This study was supported by project PIP 1484. Financial support from the Argentinean National Council of Scientific and Technological Research (CONICET) to which CN belongs, is acknowledged.