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Ephemeroptera: Ephemerellidae of Gunnison County, Colorado

Attenella margarita
Little Western Blue-Winged Olive

(Needham 1927)
Updated 20 May 2025
TSN 101343

Locations Collected

Gunnison River, Tomichi Creek, Cebolla Creek

Good Links

Photos - from Troutnut.com

Photos, Map, Taxon Identifier Numbers - from the Global Biodiversity Information Facility Attenella margarita at Gbif

Photos, Map, Museum specimens, DNA - Barcodinglife.org

North American distribution map - flyfishingentomology.com

References

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.

Hawkins,CP 1985 Food habits of species of ephemerellid mayflies (Ephemeroptera: Insecta) in streams of Oregon. American Midland Naturalist 113(2) 343-352. PDF

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 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."

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.
     Abstract: "The Timpanoga complex is a holophyletic group of mayflies in the subfamily Ephemerellinae consisting of 21, mostly North American species, distinguished by the absence of lamellate gills on abdominal segment 3 in the larvae, and associated absence of the gill socket remnants in subimagos and adults. A phylogenetic reclassification is proposed, based on a cladistic analysis, and is an example of reclassification necessary in much of the Ephemeroptera. Of the options available for generic classification, the one proposed is both informative in terms of expressing diversity within the complex and practical in terms of allowing morphological differentiation in all life stages, including both sexes of alate stages. Three main sequential lineages are recognized as the genera Attenella, Eurylophella, and Timpanoga [=Dannella n. syn.]. The two main phylogenetic branches in Eurylophella are treated as subgenera Dentatella and Eurylophella s.s. The two main phylogenetic branches of Timpanoga are treated as subgenera Dannella and Timpanoga s.s. A key to known stages of genera and subgenera incorporates newly discovered characteristics of gill socket and posterolateral projection remnants in adults and subimagos, and polar cap characteristics of eggs. A cladogram of the four species of Attenella indicates that A. soquele and A. attenuata are sister species commonly derived with a sister branch represented by A. margarita, and that these three species represent a sister group of A. delantala."

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.


Serrana,JM; Li,B; Sumi,T; Takemon,Y and Watanabe,K 2022 Implications of taxonomic and numerical resolution on DNA metabarcoding-based inference of benthic macroinvertebrate responses to river restoration. Ecological Indicators, 135, p.108508. HTML
     Quote: "At the species level with the metabarcoding dataset, six species, i.e., Wormaldia gabriella, Attenella margarita, Haemaphysalis flava, Rhyacophila malkini, Ordobrevia nubifera, and Hydropsyche oslari were identified as indicators with significant associations with the non-dam impacted sites (DAM-GB + and DAM-GB-). "

Studemann,D and Landolt,P 1997 Eggs of Ephemerellidae (Ephemeroptera). Ephemeroptera & Plecoptera: Biology-Ecology-Systematics. Mauron Tinguely and Lachat SA, Fribourg, pp.362-371. PDF

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

Zuellig,RE; Heinold,BD; Kondratieff,BC and Ruiter,DE 2012 Diversity and Distribution of Mayflies (Ephemeroptera), Stoneflies (Plecoptera), and Caddisflies (Trichoptera) of the South Platte River Basin, Colorado, Nebraska, and Wyoming, 1873-2010. U.S. Geological Survey Data Series 606, 257 p. PDF - caution 46MB
     Quote from page 25: "Remarks: This species occurs in Western and Northeastern North America but is much more common in the western portion of its range (McCafferty and others, 1993). This species probably is more common in the SPRB than these records indicate." The elevation range is 5,250-7,600 feet.


Brown,WS 2004 Ephemeroptera of Gunnison County, Colorado, USA
www.gunnisoninsects.org