Ephemeroptera: Caenidae of Gunnison County, ColoradoCaenis amica - Small Squaregill MayflyHagen 1861Updated 9 September 2025
Good LinksOther Websites: Photos, Map, Museum specimens, DNA - Barcodinglife.org North American distribution map - flyfishingentomology.com ReferencesClare,EL; Barber,BR; Sweeney,BW; Hebert,PDN and Fenton,MB 2011. Eating local: influences of habitat on the diet of little brown bats (Myotis lucifugus). Molecular Ecology, 20(8), pp.1772-1780. PDFAbstract: "We employ molecular methods to profile the diet of the little brown bat, Myotis lucifugus, and describe spatial and temporal changes in diet over their maternity season. We identified 61 prey species of insects and 5 species of arachnid. The largest proportion of prey (~32%) were identified as species of the mass-emerging Ephemeroptera (mayfly) genus Caenis. Bats roosting in agricultural settings had lower dietary richness than those occupying a roost located on a forest fragment in a conservation area. We detected temporal fluctuations in diet over the maternity season. Dipteran (fly) species dominated the diet early in the season, replaced later by species of mayfly. Because our methodology provides species-level identification of prey, we were able to isolate environmental indicator species in the diet and draw conclusions about the location and type of their foraging habitat and the health of these aquatic systems. The species detected suggested that the bats use variable habitats; members of one agricultural roost foraged on insects originating in rivers or streams while those in another agricultural roost and the forest roost fed on insects from pond or lake environments. All source water for prey was of fair to good quality, though no species detected are intolerant of pollution thus the habitat cannot be classified as pristine. Our study outlines a model system to investigate the abiotic and biotic interactions between habitat factors through this simple food chain to the top predator." Hagen,HA 1861 Synopsis of the Neuroptera of North America with a list of South American species. Smithsonian Miscellaneous Collections 4, 1-344. Hagen described Caenis amica for the first time in this publication. Hagen's Glossary (pdf) 
Malzacher,P 2022 Trait evolution of the male genitalia in the speciose genus Caenis, with emphasis on forcipes structure (Insecta: Ephemeroptera: Caenidae). Integrative Systematics: Stuttgart Contributions to Natural History, 5(1). PDF errata McCafferty,WP 1998 Ephemeroptera and the Great American Interchange. Journal of the North American Benthological Society 17(1)1-20 PDF Abstract: "The Panamerican Ephemeroptera fauna is evaluated with respect to the interchange of generic lineages and species between the Americas, and comparisons are drawn with classical studies of the American interchange based on other biota. Cladistic, distributional, and behavioral data are presented or reviewed that support the following hypotheses and conclusions: The Central American corridor has strongly favored northward dispersal, with 29 of 85 potential South American donor genera having infiltrated Central America, and 21 of those having further penetrated Nearctic North America. Only 10 of 63 potential North American donor genera have dispersed into Central America, and of those only Cercobrachys, Choroterpes, Epeorus, and Hexagenia have broached the Central American corridor. Only 8 species among the genera Campylocia, Cloeodes, Euthyplocia, Guajirolus, Hexagenia, Mayobaetis, and Tortopus co-occur in South and Central America. All belong to South American lineages, and 5 are large, relatively strong flying ephemeroid mayflies--the 3 belonging to Euthyplocia and Hexagenia having further penetrated North America. Species range extensions between North and Central American are less restricted, with 34 species of genera of South American origin and 9 species of genera of North American origin co-occurring in the continental Neotropics ("Central America") and Nearctic region ("North America") of the Northern Hemisphere. Late Neogene and Holocene dispersal can account for most infiltration of Central America as well as interchanges across the corridor. Bi-directional dispersal is evident in Caenis and Hexagenia. Vicariance has evidently affected the Panamerican distribution of Hexagenia and Homoeoneuria. Mid-Tertiary or earlier southward and more recent northward dispersal of Hexagenia is consistent with the distribution and phylogeny of the genus. A relatively early northward dispersal of Homoeoneuria is suggested by the presence of a distinct lineage in South America and the Holarctic sister relationship of Homoeoneuria and Oligoneurisca. Distributional pattern analysis predicts that the widespread Panamerican genus Callibaetis is of South American origin." McCafferty,WP; Durfee,RS and Kondratieff,BC 1993 Colorado mayflies (Ephemeroptera): an annotated inventory. Southwestern Naturalist 38 3, 252-274. PDF Quote from page 268 "Colorado is one of the few areas in North America from which this ubiquitous species had been previously unreported (Provonsha, 1990)." The authors also mention at the end of their discussion of Faunisitics that C. amica is one of "those mayfly species that are truly widespread in North America" McCafferty,WP and Provonsha, AV The Mayflies of North AmericaSpecies List (Version 8Feb2011) Here is the geographic range and synonyms: Caenis amica Hagen, 1861 [CAN:NE,NW;MEX:SW;USA:FN,NE,NW,SE,SW]
* Caenis simulans McDunnough, 1931 (syn.)
McDunnough,J 1931 New species of North American Ephemeroptera. Canadian Entomologist 63, 82-93.
Discussed as Caenis simulans Nienhaus,H; Fitzpatrick,SW; Bloom,DD and Schriever,TA 2023 Dispersal ability and biogeographic gradients influence gene flow of three aquatic insects in Laurentian Great Lakes interdunal wetlands. Freshwater Science 42(1) 88-103. Abstract: "Population genetic connectivity is influenced by multiple abiotic and biotic attributes, including geography, dispersal ability, and life history, which may lead to different patterns of population structure of organisms occupying similar habitats. We investigated how differences in dispersal ability and biogeographic gradients correspond with population structuring of 3 aquatic insect species found within naturally fragmented interdunal wetlands along the eastern shoreline of Lake Michigan in midwestern USA. Interdunal wetlands are small, highly fragmented, and patchily distributed along the eastern coast of Lake Michigan, USA. Our focal species, Anax junius (Drury, 1773), Notonecta undulata Say, 1832, and Caenis amica Hagen, 1861 were chosen as high, intermediate, and low dispersers, respectively. We hypothesized that all insect populations experience isolation by distance with relatively low gene flow among sites, but that the strength of isolation by distance varies with dispersal ability. We used cytochrome c oxidase subunit I sequence data to confirm species identification and restriction enzyme-association DNA sequencing for population genomic analyses. Our cytochrome c oxidase subunit I data revealed that Caenis populations consisted of multiple species split along a latitudinal gradient. Restriction site-association DNA sequencing data showed that A. junius displayed strong isolation by distance, where N. undulata did not. Additionally, both A. junius and N. undulata populations displayed 2 genetic clusters along the coastline, and genetic diversity increased along with latitude. These results indicate that biogeographical variables, such as latitude and covarying abiotic factors, may be stronger predictors of population structure than dispersal ability and that inference of population structure within aquatic macroinvertebrates should be on a species-specific basis." Provonsha,AV 1990 A revision of the genus Caenis in North America (Ephemeroptera: Caenidae). Transactions of American Entomological Society 116, 801-884. Abstract: "The North American species of the genus Caenis are revised, and illustrated keys to larvae and adults presented. Eleven nominal species, including one new species, are recognized. Based on shared morphological and behavioral characters in the larvae, adults, and eggs, these species are grouped as follows: diminuta group - C. amica Hagen, C. candida Harper and Harper, C. diminuta Walker, C. latipennis Banks, C. punctata McDunnough, and C. youngi Roemhild; hilaris group - C. anceps Traver, C. hilaris Say, C. macafferti n. sp., and C. tardata McDunnough. Caenis bajaensis Allen and Murvosh appears to have been independently derived and is not placed in either group. For each nominal species, synonymies, larval and adult descriptions, figures, and a discussion of taxonomy, distribution, and biology and ecology, are included. Newly discovered synonyms are: C. amica Hagen = C. simulans McDunnough n. syn.; C. latipennis Banks = C. forcipata McDunnough n. syn., C. jocosa McDunnough n. syn., C. delicata Traver n. syn., C. gigas Burks n. syn." Rodgers,EB 1982 Production of Caenis (Ephemeroptera: Caenidae) in elevated water temperatures. Freshwater Invertebrate Biology, 1(2)2-16. Abstract: " Annual production rates of a mayfly (tentatively Caenis sp. nr. amica: Ephemeroptera) inhabiting large outdoor channels at four diurnally and seasonally fluctuating temperature levels were calculated. Temperature levels were ambient Tennessee River temperature, and about 3°, 6°, and 9C above ambient. Caenis were sampled from December 1977 through September 1978. Emergence was accelerated 4 to 31 days by elevated temperatures. Long emergence periods (80 to 100 days) and size-frequency data indicated bivoltinism. Production in ambient temperatures 676.04± 237.56mg D W / m2/ yr) was significantly greater than in any other temperature level. Production rates in the three elevated temperatures were 205.66± 67.30mg DW/m2 in + 3 channels, 272.86± 78.23mg DW/m2 in + 6 channels, and 271.10± 93.47mg DW/m2 in + 9 channels. These data imply that this population of Caenis is existing at or above its optimal temperatures." Sun,L and McCafferty,WP 2008 Cladistics, classification and identification of the brachycercine mayflies (Insecta: Ephemeroptera: Caenidae). Zootaxa 1801: 1-239. Abstract: " The mayfly subfamily Brachycercinae (Pannota: Caenidae) is redefined and shown to be an apotypic, monophyletic group based on numerous synapomorphies, including, for example in the larvae, the presence of ocellar tubercles, an anterior row of long setae on the larval head capsule, a patch of long setae posterior to the base of the glossae, a broad prosternum, and the absence of toothlike claw denticles. Over 100 morphological characters of larvae, adults, and eggs discovered to be useful for phylogenetic analysis and diagnoses are detailed and illustrated. Thirty-eight species are recognized among the genera Brachycercus Curtis, Caenoculis Soldán, Cercobrachys Soldán, Insulibrachys Soldán, Sparbarus, n. gen., Oriobrachys, n. gen., Latineosus, n. gen., Susperatus, n. gen., and Alloretochus, n. gen., by adopting a strictly phylogenetic classification, including a first tribal classification within the subfamily. Brachycercus ojibwe, n. sp., Cercobrachys fox, n. sp., C. lilliei, n. sp., C. pomeiok, n. sp., C. winnebago, n. sp., Latineosus cayo, n. sp., L. cibola, n. sp., Oriobrachys mahakam, n. sp., Sparbarus choctaw, n. sp., S. coushatta, n. sp., S. miccosukee, n. sp., and Susperatus tonkawa, n. sp. are newly described. The Nearctic Brachycercus articus Soldán, n. syn., and B. edmundsi Soldán, n. syn., are shown to be equivalent to B. harrisella Curtis, proving the latter to be a widespread Holarctic species. Sparbarus capnicus (Zhou, Sun and McCafferty), n. comb., S. corniger (Kluge), n. comb., S. europaeus (Kluge), n. comb., S. gilliesi (Soldán and Landa), n. comb., S. japonicus (Gose), n. comb., S. kabyliensis (Soldán), n. comb., S. lacustris (Needham), n. comb., S. maculatus (Berner), n. comb., S. nasutus (Soldán), n. comb., S. tubulatus (Tshernova), n. comb., Susperatus prudens (McDunnough), n. comb., and S. tuberculatus (Soldán), n. comb., are transferred from Brachycercus. Alloretochus peruanicus (Soldán), n. comb., and Latineosus colombianus (Soldán), n. comb., are transferred from Cercobrachys. Caenis dangi (Soldán), n. comb., is transferred from Caenoculis and Brachycercinae to Caeninae, and provisionally placed in Caenis Stephens. Sparbarus flavus (Traver), n. comb., is transferred from Brachycercus and considered to be a nomen dubium. Nomenclatural history, new or revised descriptions as appropriate, diagnoses, illustrations, and keys are provided for known stage of species. Origins and evolutionary relationships of the Brachycercinae are hypothesized based on cladistic results. Brachycercinae is considered to have originated from a Caenis-like ancestor. The genera Caenoculis and Insulibrachys represent more ancestral lineages, whereas the genera Sparbarus, n. gen., Brachycercus, Oriobrachys, n. gen., Latineosus, n. gen., Susperatus, n. gen., Alloretochus, n. gen., and Cercobrachys appear more derived. Cercobrachys pomeiok and other closely related species are most apotypic in terms of numbers of accumulated apomorphies." Wang,T-Q; McCafferty,WP and Bae,YJ 1997 Sister relationship of the Neoephemeridae and Caenidae (Ephemeroptera: Pannota). Entomological News 108:52-56. Webb,JM; Jacobus,LM; Funk,DH; Zhou,X; Kondratieff,BC; Geraci,CJ; DeWalt,RE Baird,DJ Richard,B Philips,I and Hebert,PDN 2012 A DNA barcode library for North American Ephemeroptera: Progress and prospects. PloS One 7(5): e38063 HTML Under the section titles "Barcode Distances between Species", the authors state: "Among Caenis amica Hagen, C. punctata McDunnough, and C. youngi Roemhild, the interspecific distances were as low as 0.3% (maximum intraspecific distances ranged from 3.7-21.9% and none of the species were monophyletic), possibly an artifact of incomplete taxonomic knowledge or historical introgression. For nearly all other species, the minimum interspecific distances were much greater (mean: 12.5%)." In other words these three species may actually be one, but further collecting and DNA analysis is nessecary to answer this question. Wujek,DE 2013 Epizooic diatoms on the cerci of Ephemeroptera (Caenidae) naiads. The Great Lakes Entomologist, 46(1 & 2), p.8. PDF Abstract: "Using scanning electron microscopy, epizooic diatoms were observed growing on the cerci of Caenis amica Hagen naiads (Ephemeroptera, Caenidae). Meridion circulare (Greville) C. Agardh was the most abundant, followed by Synedra rumpens Kützing, then Cocconeis pediculus Ehrenberg. Other diatom species observed from substrates in Cedar Creek, Isabella County, Michigan were not observed on the cerci. No diatoms were observed on Ephemerellidae naiads." 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 widespread and common species can be found in many types of lentic and lotic habitats across the U.S. (Provonsha, 1990) and may be more common in the SPRB than records indicate." The elevation range is 2,850-5,050 feet and the adults emerge from May-July. |