Ephemeroptera: Ephemerellidae of Gunnison County, Colorado
Attenella margarita (Needham 1927)
Little Western Blue-Winged Olive
Updated 19 Apr 2017
Gunnison River, Tomichi Creek, Cebolla Creek
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Argyle,DW and Edmunds,GF 1962 Mayflies (Ephemeroptera) of the Curecanti Reservoir Basins Gunnison River, Colorado. University of Utah Anthropological Papers 59 8, 178-189.
Discussed as Ephemerella margarita. Quote from page 188: " The nymphs of this species were very young and many of them were probably not detected in hand screen collections. " They collected their nymphs on July 7th and 8th, 1961.
Gilpin,BR and Brusven,MA 1970 Food habits and ecology of mayflies of the St. Maries River in Idaho. Melanderia 4:19-40. PDF
Discussed as Ephemerella (Attenuatella) margarita.
McCafferty,WP 1977 Biosystematics of Dannella and related subgenera of Ephemerella (Ephemeroptera: Ephemerellidae). Annals of the Entomological Society of America, 70(6) 881-889. PDF
Abstract: " The subgenera Attenella, Eurylophella, Dannella, and Timpanoga of the genus Ephemerella form a monophyletic group of subgenera whose interrelationships are retraced phylogenetically. Dannella and the more highly derived Timpanoga form sister groups divergent from the highly derived Eurylophella, while Attenella is more ancestral in origin. Ephemerella (Dannella) provonshai sp. n. shares an immediate common ancestor with E. simplex. The adult stage of E. lita is described for the first time, and keys and comparisons are given for the species of Dannella. Phylogenetic data substantiate the subgeneric classification of the last 18 years and permit certain biogeographic inferences."
Jacobus LM and Fleek ED. 2010 Insecta, Ephemeroptera, Ephemerellidae, Attenella margarita (Needham, 1927): Southeastern range extension to North Carolina, USA. Check List 6(2):311-313. PDF
Jensen,SL 1966 The Mayflies of Idaho (Ephemeroptera). M.S. Thesis, University of Utah, Utah. 364 p.
Discussed as Ephemerella margarita. Quote from Page:240 " Needham(1927b) described this species from several localities in Utah, and McDunnough (1931c) correctly associated the imagos from Alberta. Allen and Edmunds (1961b) provide descriptions of the adults and mature nymphs.
Taxonomy and Biology: This species is the only representative of the subgenus known to occur in Idaho and is easily distinguished by characters given in the keys. In addition, the nymphs are easily identified by the short caudal filaments (2-3 mm) that are distinctly curved ventrad. The nymphs also display distinct sexual size dimorphism; the females ranging in body length from 7.5-9.0 mm, and the males from 5.5-7.0 mm. The male nymphs are usually much darker in color than are the females and display a more sttriking color pattern.
Nymphs of this species usually occur uncommomly in moderately flowing rivers and streams along the margins among silt and moss covered rocks and gravel. They have been collected at elevations ranging from 3,000 to 7,000 feet and in summer daytime water temperatures of 55° to 77°F. Large series of nymphs are uncommon in collections. Adults have been reported by Allen and Edmunds (1961b) as occuring from July to late August.
Distribution: Ephemerella margarita is a noreal monotypic species with separate populations in easaterna nd western orth America. "
McCafferty,WP and Durfee,RS; Kondratieff,BC 1993 Colorado mayflies (Ephemeroptera): an annotated inventory. Southwestern Naturalist 38 3, 252-274. PDF
Quote from page 264: "This species has a somewhat unusual distribution pattern in North America. It is known from populations in the extreme northeastern United States and eastern Canada as well as western populations from British Columbia to New Mexico. It is most common in the western slope/plateaus region of Colorado."
McCafferty,WP and Provonsha, AV The Mayflies of North AmericaSpecies List (Version 8Feb2011)
Here is the geographic range and synonyms:
Attenella margarita (Needham), 1927 [CAN:NE,NW;USA:NE,NW,SE,SW]
* Ephemerella margarita Needham, 1927 (orig.)
McCafferty,WP and Wang,T-Q 1994 Phylogenetics and the classification of the Timpanoga complex (Ephemeroptera: Ephemerellidae). Journal of the North American Benthological Society 13 4, 569-579.
McCafferty,WP; Wang,T-Q 2000 Phylogenetic systematics of the major lineages of Pannote mayflies (Ephemeroptera: Pannota). Transactions of American Entomological Society 126 1, 9-101.
Needham JG. 1927. The Rocky Mountain species of the mayfly genus Ephemerella. Annals of the Entomological Society of America 20:107-117.
Described the nymph as Ephemerella margarita.
Ward,JV and Stanford,JA 1990 Ephemeroptera of the Gunnison River, Colorado, USA. In: Mayflies and Stoneflies. Ed: Campbell,IC Kluwer Academic Publishers, 215-220.
The United States Geological Survey (USGS) National Water Quality Assessment Data Warehouse (NAWQA) shows this species is present in Gunnison County. Data as of 1Sep2005