Great Basin Naturalist


An inventory and analysis of the mayfly (Insecta, Ephemeroptera) fauna of New Mexico, based on the published literature and study of extensive materials from diverse collections, indicated the presence of 12 families, 37 genera, and 81 species. Of these, 25 represent new state records: Acentrella turbida, Ameletus falsus, A. sparsatus, Baelis adonis, B. bicaudatus, B. flavistriga, Baetodes deficiens, Caenis latipennis, Callibaetis fluctuans, Cinygmula par, Ephemera simulans, Hexagenia bilineata, Isonychia sicca, Labiobaetis propinquus, Lachlania saskatchewanensis, Leptophlebia bradleyi, Leucrocuta petersi, Neochoroterpes nanita, Paraleptophlebia debilis, P. heteronea, Procloeon conturbatum, Rhithrogena plana, R. robusta, R. vita, and Thraulodes gonzalesi. Baetodes deficiens represents a new USA record. For 37 of the 56 previously reported and confirmed species, 124 new county records are provided. With respect to continental affinities, 34 species are western, 27 southwestern, 13 widespread, 1 is a southern USA species, and 1 eastern. Of the major drainage systems of the state, the Gila system is the most species rich with 48 species, followed by the Rio Grande (46), Pecos (39), Candadian (28), and San Juan (25). Relationships between drainage systems and between New Mexico and broadly adjoining states are discussed. Lachlania dencyannae, the only endemic species in New Mexico, occurs in the Gila system and is rare and endangered. Certain other species from the Gila system are also noted as being at risk. From other drainages, B. Adonis, Ephemerella mollitia, and L. petersi also are of some concern at the national level. Additional species that are rare in New Mexico and are of concern at least at the state level include Ametropus albrighti, C. fluctuans, Il. bilineata, L. bradleyi, N. nanita, P. conturbatum, and R. hageni.