ISSN 1911-2173

The Taxonomy of the North American Species of Parameletus Bengtsson, 1908 (Ephemeroptera: Siphlonuridae), with Keys to Nymphs and Male Imagos

Steven K. Burian

Department of Biology, Southern Connecticut State University, 501 Crescent St., New Haven, CT USA 06515 (

The Taxonomy of the North American Species of Parameletus Bengtsson, 1908 (Ephemeroptera: Siphlonuridae), with Keys to Nymphs and Male Imagos

The Taxonomy of the North American Species of Parameletus Bengtsson, 1908 (Ephemeroptera: Siphlonuridae), with Keys to Nymphs and Male Imagos

Steven K. Burian

Department of Biology, Southern Connecticut State University, 501 Crescent St., New Haven, CT USA 06515 (


In North America, the Holarctic genus Parameletus Bengtsson is widely distributed across the northern tier of the continent and parts of the Rocky Mountains. Four species occur in North America (Parameletus cheliferP. columbiaeP. croesus, and P. midas) with P. chelifer having the greatest range and currently the only species of Parameletus detected broadly across the subarctic of Canada. In this paper, new detailed comparative descriptions are provided for nymphs and imagos. The nymph of P. croesus is described for the first time. A final instar nymph of P. croesus was positively associated with the male imago stage based on the observation of diagnostic characters of the male imago through the cuticle of the last instar nymph. New illustrated keys to male imagos and late instar nymphs are presented. New distribution records are presented and geographic variation in diagnostic characters of species is discussed. New information on the aquatic habitats of nymphs and the biology of species is presented.

Parameletus midas (McDunnough) (photo by Steven Burian)


Among the mayflies of higher latitudes (i.e., 50°–70°N ) of the Northern Hemisphere, species of the genus Parameletus Bengtsson are conspicuous, widespread, and ecologically important (McDunnough 1923, 1930, 1938, Edmunds 1952, 1957, Harper and Harper 1981, Söderstrom 1988, Söderstrom and Nilsson 1986, 1987, Giberson et al. 2007, and Tiunova 2008). The genus Parameletus was described from Sweden by Bengtsson (1908) and since then it has been the subject of many studies (Bengtsson 1909, Esben-Petersen 1916, McDunnough 1923, 1930, 1938, Traver 1935, Speith 1938, Daggy 1941, Edmunds 1952, 1957, Brinck 1957, Edmunds et al. 1976, Hubbard 1977, Söderstrom and Nilsson 1986, 1987, Studemann and Tomka 1991, Tiunova 2008, and Webb et al. 2012). Historically, the complex nomenclatural history of Parameletus produced much confusion as to the validity of the genus and its type species. Hubbard (1977) reviewed and clarified the nomenclature of Parameletus and P. chelifer (its type species) and thereby produced the current level of taxonomic stability for Parameletus. All previous synonyms for Parameletus were listed by Hubbard (1977) and there have been no new additions to his list. Despite stability in the genus name there have been continuing problems concerning the taxonomy of its species.
In North America species of the Parameletus are known mostly from the male imago, but this life stage is rarely collected. Currently 4 species of Parameletus are known from North America, 3 restricted to the Nearctic (P. columbiae McDunnough, P. croesus (McDunnough), and P. midas (McDunnough)) and 1 that is Holarctic (P. chelifer Bengtsson). Although the imagos of all 4 species and the nymphs of all but 1 species of North American Parameletus have been variously described and partially figured (McDunnough, 1923, 1938, Traver 1935, Spieth 1938, Daggy 1941, Edmunds 1952, Jensen 1966, Söderstrom and Nilsson 1986, and Tiunova 2008) the taxonomic treatments are incomplete and not comparable. There are no comprehensive keys to imagos or nymphs. Consequently, because the appropriate taxonomic tools were lacking, we know little about the life history, ecology, or distribution of Parameletus species.
The earliest account of Parameletus in North America was given by McDunnough (1923) where he described both P. croesus and P. midas in a single paper. Even though McDunnough (1923) did include basic outline drawings of the male genitalia of these species, the lack of detail greatly limited their usefulness. The species accounts of P. croesus and P. midas focused mostly on details of color and color patterns of male imagos with female imagos receiving similar, but briefer treatment. McDunnough (1930) later provided additional details of the nymph of P. midas and indicated that the reader should compare his figures of the gill and mouthparts of P. midas to those of P. chelifer presented by Ebsen-Petersen (1916). Unfortunately, McDunnough’s figures (as well as those by Ebsen-Petersen) were too rudimentary to be used for any detailed comparison. Traver (1935) redescribed the male imago of P. midas and P. croesus (despite admitting that she was only able to study specimens of P. midas) and provided a key that relied on the use of pigmentation of the forewing membrane to separate these species. Traver (1935) did provide figures of the wings and male genitalia of P. midas. Although figures of the wings seem quite accurate, her figure of the male genitalia of P. midas has some problems. Principally Traver’s figure of the genitalia P. midas has 3 problems (1) the transparent inner edges of the lobes of the penes lobes were omitted, (2) the figure is presented from the dorsal perspective and shows paired blunt lobes crossing under the sharp inward curving paired spines; this is incorrect because the blunt lobes are actually ventral structures and should only be indicated as dotted lines dorsally, and (3) dorsally there appears to be 2 slender sharply pointed spines with diverging tips that arise near the base of the penes; these spines do not exist and what appears as spines are actually the thick edges of the large sharp inward curving spines of the dorsal surface of the penes.
Eight years after he described P. croesus and P. midas, McDunnough (1938) described P. columbiae based on imagos that were collected from a swarm above a glacial stream in British Columbia, Canada. In that same paper he also noted the first North American record of P. chelifer based on imagos collected from Churchill, Manitoba, Canada. In support of his earlier work McDunnough (1938) also provided much improved figures of the male genitalia of P. chelifer and P. midas. Although McDunnough’s new figures for these species were much needed so was information on P. croesus,  no new figures or details were presented. Until now this has been a problem concerning P. croesus, because except for the unpublished (and virtually unknown) figure of the male genitalia of P. croesus in Daggy’s (1941) Ph.D. thesis on Minnesota mayflies, there were no detailed illustrations of its genitalia available for study.
The next major contribution to the study of North American Parameletus was made by Edmunds (1952, 1957) who reported on a population of P. columbiae that he discovered at altitude (~2100–2500 m ASL) in the Rocky Mountains of Utah. In his Ph.D. thesis, Edmunds (1952) redescribed the male and female imago and provided the first account of the nymph of P. columbiae, but none of these taxonomic accounts were ever published. Edmunds did however publish his observations of the life history of P. columbiae noting its remarkably short development time, 16–21 days at the Brighton, UT site (Edmunds 1957, Edmunds et al.1976). Despite not publishing some of his earlier taxonomic work, Edmunds’ studies facilitated the survey of Idaho mayflies by Jensen (1966), wherein he reported additional new records of P. columbiae. Subsequently P. columbiae became the best studied of any species of Parameletus in North America, but because of the lack of knowledge of the other Nearctic species of Parameletus this contributed to a rather narrow view of the life history and habitat of the genus at that time. Details of the of life history and habitat of P. columbiae were presented by Edmunds et al.(1976) in a way that has frequently led to a misunderstanding of the entire genus in North America. Studies on the biology of the Holarctic species P. chelifer (Söderstrom and Nilsson 1987, Söderstrom and Johansson 1988, and Söderstrom 1988) clearly indicate a wider range of environmental tolerances and a more variable developmental period than what is known for P. columbiae. New data on the habitat of nymphs and estimates of development times are presented here for P. midasP. croesus, and P. chelifer.
Jacobus and McCafferty (2002) briefly commented on the status of P. croesus based on their study of the types. They noted that even though P. croesus had not been collected for 75 years, it was premature to declare it extinct. This was a prudent decision, especially since Daggy (1941) collected a swarm of P. croesus in 1939, only 63 years earlier. Wing characters discussed by Jacobus and McCafferty (2002) for separating P. croesus from P. midas are now determined to be unreliable based on the study of additional specimens of these species. Webb et al. (2012) presented some data on Parameletus species as part of a larger project to quantify a portion of the regional species pool of the Canadian lower Arctic using DNA barcodes. The use of molecular marker sequences to assist in determining species has been a positive step toward addressing the problems of identifying species from life stages and material for which there are no useful traditional taxonomic keys. Webb et al. (2012) used the COI marker sequence to confirm the co-occurrence of P. midas and P. chelifer in samples from Churchill, Manitoba. Their consensus analysis of sequence divergence values also showed a strong association of samples of P. midas from Manitoba and New Brunswick with clear separation from samples of P. chelifer. The previous record of P. midas at the Churchill site (Harper and Harper 1981) had been somewhat suspect because it was far removed from what had been believed to the major part of the range of P. midas in eastern Canada, because there were no other sites known for the species between those two areas, and because the original adult material upon which the record was based could not be located for study. Kjærstad et al. (2012) briefly commented on the high degree of similarity in molecular marker sequences obtained for specimens of P. chelifer from Finmark region of Scandinavia and from Churchill, Manitoba, Canada. Their findings strongly support the true Holarctic status of P. chelifer and recognize the important genetic connection between Nearctic and Palearctic populations. The most recent treatment of Nearctic Parameletus was by Klubertanz (2016) who summarized the known distribution of the genus in Wisconsin, but did not include any new records for that region. Finally there are other publications that include either brief taxonomic overviews of the genus (e.g., Burks 1953) or enigmatic distribution records without specifics (e.g., Edmunds et al. 1976); in most instances these treatments simply summarized what was already known about the genus and do not contribute any new information.
Despite all of the work done on North American Parameletus during the past 89 years, nymphs (the most frequently collected life stage) cannot be reliably identified to species. Moreover, the use of incomplete keys to nymphs has led to widespread misidentifications adversely affecting estimates of regional species diversity and inhibited new studies on the biology and ecology of the Nearctic species of Parameletus. To a lesser extent, incomplete and poorly illustrated keys for male imagos have also contributed to this problem. The focus of this study was to update and complete the taxonomy of the species of Parameletus in North America and produce new keys for nymphs and imagos. The distributions of all species are plotted and discussed. New information on the aquatic habitats, emergence times, and conditions are also presented.

Methods & Materials

Although it would have been desirable to obtain new reared material for all Nearctic Parameletus species, unfortunately this was not possible because of the difficulty in obtaining live nymphs for rearing. Parameletus midas was the only species for which a new series was obtained. Live nymphs of P. croesus were collected by Brigid O’Donnell in 2007 from Wisconsin, but she was unable to fully rear these specimens. Although none of O’Donnell’s specimens fully emerged, one final instar male nymph was positively associated with the male imago of P. croesus. The association was made by the recognition of diagnostic characters of the male imago on the developing subimago visible through the cuticle of the last instar nymph, hence a complete association between the nymph and imago stage. Unequivocal diagnostic characters were the dark medial marks on the abdominal sterna of the male imago and the deep v-notched styliger plate. These characters were unmistakable through the nymphal cuticle and provide the same level of primary evidence of immature-adult association as if the specimen had fully emerged. Therefore it was not considered to be a tentative association. In addition, there were other secondary lines of evidence to support the association. First, nymphs of all other species of Nearctic Parameletus were known and morphological study of all nymphs from Wisconsin showed that they were different from those associated with all other known North American species. Second, no adults of any species except P. croesus have ever been collected in the region of Minnesota and Wisconsin. Third, all specimens of Parameletus nymphs studied from Wisconsin are morphologically congruent with the nymph associated by adult diagnostic characters to be that of P. croesus. Finally, with the intensity of entomological studies conducted in Wisconsin over the past 63 years by some of the most experienced aquatic entomologists in the United States (e.g., William Hilsenhoff), it is highly unlikely that if a different species of Parameletus was present that they would have failed to have found it (even if they didn’t know what it was). All of these lines of evidence taken together strongly support the conclusion that all nymphs deemed morphologically congruent with the one specimen which was positively associated with the adult stage of P. croesus (by observation of adult diagnostic characters) were the nymphs of P. croesus.
Live nymphs of P. midas were collected from the Dead River, Maine, USA using a standard D-frame kick net, transferred to 500 ml plastic jars containing stream water from the collections site. Jars were aerated and slightly chilled for transport to the laboratory. In the laboratory nymphs were placed in large circular glass culture dishes (dia. ~ 23 cm) with emergent vegetation from the field site. Emergent vegetation placed in rearing dishes provided a natural surface for the final instar nymphs to crawl up (as do other siphlonurids) at the time of emergence. Each rearing dish was aerated with a small airstone and covered with a self-supporting domed mesh enclosure that allowed space for subimagos to fly away from the water. Water temperature in rearing dishes was maintained as close to 17°C as possible (field water temperature where black wing pad nymphs were collected ranged from 16.9–17.4°C). Subimagos were removed upon emergence to subimago boxes to make the final molt and associated nymphal exuviae were preserved in 80% alcohol and kept with each subimago until it molted. Imagos were preserved in 80% alcohol with the associated nymphal exuviae.
All specimens were observed for morphological characters, coloration, and color patterns under stereoscopic and compound light microscopes (up to 1000x magnification). Mouth and body parts of the nymphs were dissected in 80% alcohol and slide mounted in Hoyer’s Mounting Media or Euparal®. Male genitalia were slide mounted for study and examined intact. Study of intact genitalia is important because subtle and membranous features are highly susceptible to distortion during and after slide mounting. Some of the type material was slide mounted by the original authors and studied in that form. Imago wings were also examined and measured intact. Standard terminology for adult anatomy and morphology was used (Kluge 1994). Standard terminology for nymphs given by Kluge et al. 1995 was used except for the names given to sclerotized supports for abdominal gills. All abdominal gills of Parameletus nymphs have a sclerotized ventral strip with setae and a sclerotized mid-rib. These structures are identified as the fore costa (FC–ventral strip) and hind costa (HC–mid rib) by Kluge et al. 1995, but because of the similarity between these terms and the well-established name of the primary wing vein “costa” I have elected not to use them to avoid any confusion. The abbreviation PLPs is used to refer to the posterolateral projections of abdominal terga of nymphs and where necessary of a specific tergite (e.g., PLPs-tergite IX). Tarsal segments of legs of imagos are abbreviated as an uppercase “T” and a subscript denoting a specific segment number or range of segments (e.g., T1 refers to tarsal segment 1). In the materials studied and appendix sections the abbreviation Nex refers to shed nymphal exuviae. Specimens were photographed using a Nikon D300s DSLR and the Nikon Camera Control Pro2® software. All measurements were made using a calibrated ocular micrometer (nearest 0.10 mm). Measurements were made from entire specimens and/or parts (not mounted on slides) that were held as flat as possible (without inducing distortion) using sections of broken glass microscope slides and coverslips. Conventions for standard measurements described by Hubbard (1995) were followed. Means and standard deviations (abbreviated as SD) were calculated for all continuous data. Lengths of the foreleg segments of the male imago were standardized to the length of the foretibia and expressed as ratios. These values represent percentages relative to the length of the foretibia. Description of colors and hues were kept as simple as possible with regard to common and standard color names. Eggs were dissected from a reared female imago in 80% alcohol. Eggs were carefully removed from the lower oviduct (to minimize differences possibly related to maturation) with a 2 µl adjustable micropipette, dehydrated in 100% propanol for 10 min. and mounted in Euparal®. Chorionic features of eggs were observed under phase contrast microscopy (400 and 1000x).
Although not comparable, basic descriptions of male imagos of P. cheliferP. columbiaeP. croesus, and P. midas are available (McDunnough 1923, 1938, Traver 1935, Söderstrom and Nilsson 1986, and Tiunova 2008). For the 3 strictly North American, species adult descriptions have focused mostly on aspects of color and color patterns of male and female imagos. In addition, most of these descriptions were composed using terminology and color descriptions that are antiquated and difficult to interpret. To facilitate a clear and unambiguous understanding of these taxa new comparable descriptions using standard terminology and updated species diagnoses (with new figures) and morphometric data are presented here. Where possible specimens believed to show the least effects of long-term preservation in alcohol were used for descriptions and diagnoses. New comparative descriptions (with new figures) are presented for near final instar nymphs.
Specimen abbreviations and symbols: ♂ = male imago; ♀ = female imago; S♂ = male subimago; S♀ = female subimago; N♂ = male nymph; N♀ = female nymph; Nex = nymphal exuviae; CNC = Canadian National Collection, Ottawa, Ontario, Canada;  CSU = Colorado State University, C.P. Gillette Museum of Arthropod Diversity, CO, USA;  FAMU = Florida A&M University, Tallahassee, FL, USA; FLBS = Flathead Lake Biological Station Collection, University of Montana, Polson, MT, USA; ILNHS = Illinois Natural History Survey Insect Collection, Champaign, IL, USA; MEIFW = Maine Inland Fish & Wildlife, Bangor, ME (specimens from this source deposited with author); NEL = Northeast Ephemeroptera Laboratory, Department of Biology, Southern Connecticut State University, New Haven, CT, USA; PERC = Purdue Entomological Research Collection, Purdue University, West Lafayette, IN, USA; SWRC = Stroud Water Research Center, Avondale, PA, USA; UAM = University of Alaska Museum of the North, University of Alaska, Fairbanks, AK, USA; UM = University of Minnesota Insect Collection, University of Minnesota, St. Paul, MN, USA; USGS-NAWQA = United States Geological Survey, National Water Quality Assessment Program, National Water Quality Laboratory, Denver, CO, USA; WDNR = Wisconsin Department of Natural Resources, Ecological Inventory and Monitoring, Superior, WI, USA. Deposition of all specimens is with the institutions listed for each record. Latitude and longitude coordinates are given, where possible, in positive and negative decimal degree format. In some instances because of vague or incomplete original locality information coordinate pairs for a site were estimated using all available descriptive location data combined with remote inspection of general vicinity of sampling area using satellite imagery and information on the circumstances under which a sample was obtained. These estimates are denoted by an (*). All georeferenced specimen data for material studied are presented in a separate excel spread sheet (Append. 1) to facilitate use of these data in mapping programs and future biodiversity analyses. A separate excel spread sheet page is also provided for all records of Nearctic Parameletus previously published so these data can also be used for geo-spatial study (Append. 1). The literature cited section of the paper includes references for previously published records that occur in Append. 1. Species distribution maps were prepared using Simplemappr® (Shorthouse 2010).

Material Studied

Parameletus chelifer Bengtsson, 1908
Material Examined. CANADA: Northwest  Territories: Horton River, Site 14 [68.47541N/ -128.634278W], D. Giberson, 23 Jul 2000, 1♂, 1♀ [NEL]; Horton River, Site 14 [68.47541N/ -128.634278W], D. Giberson, 24 Jul 2000,  5♂ [NEL]; Horton River, Site 29 [69.049639N/ -126.184833W], D. Giberson, 31 Jul 2000, 1♂,1♀ [NEL]; same, (PERC No. 0064691], same, 2♂, [PERC]; Thelon River, trib., Site 19 [64.179472N/ -102.616139W], D. Giberson & L. Purcell, 6 Jul 2002, 17N [NEL]; Thelon River, trib., Site 22 [64.184833N/ -102.318583W], D. Giberson & L. Purcell, 7 Jul 2002, 15N [NEL]; Tundra pond above Thelon River Site 27 [64.320333N/ -101.836417W], D. Giberson & L. Purcell, 8 Jul 2002, 26N [NEL]; Nunavut: Maguse River north of Arviat, swift flowing large river [61.298883N/ -94.080183W], D. Giberson, 10 Jul 2003,  1S♂, 1♀ [NEL]; Baker Lake, airport road, small pond at campground [64.315617N/ -96.053967W], D. Giberson, 14 Jul 2003, 14N [NEL]; USAAlaska: Yukon-Koyukuk Co., Fort Yukon, above Arctic Circle [66.565367N/ -145.278597W*], C.W. Pagel,  17 Jul 1965, 1♂ [NEL]; Fairbanks North Star Co., Chatanika River, puddle near Elliot Hwy bridge, (UAM No. 50463) [65.084459N/ -147.725698W*], Sch. & Berg.(?), 6 Jun 1977, 2N [UAM]; Chatanika River, old channel (UAM No. 50467)  [65.086376N/ -147.738764W*], Sch. & Berg. (?), 12 Jun 1973, 1N [UAM]; Chatanika River, old channel (UAM No. 50466) [65.086376N/ -147.738764W], Sch. & Berg.(?), 12 Jun 1973, 1N [UAM]; Chatanika River, old channel (UAM No. 50464) [65.095946N/ -147.680510W*], Sch. & Berg. (?), 23 Jun 1976, 15♀ [UAM]; Chena River, 2nd bridge (UAM No. 50484) [64.848259N/ -147.383583W*], Jink & Berg., 14 Jun 1972, 2♂ [UAM]; Salcha River, pipeline x-ing (UAM No. 50453) [64.485201N/ -146.663052W*], Sch. & Berg. (?), 22 Jun 1972, 1♂ [UAM]; Bethel Co., Holitna River (UAM No. 50458) [61.635231N/ -157.115829W*], Gar. & Berg. (?), 11 Jun 1976, 1♂ [UAM]; Holitna River (UAM No. 50461b) [61.635231N/ -157.115829W*], Gar. & Berg. (?), 26 Jun 1977, 1♂ [UAM]; Holitna River (UAM No. 50455) [61.635231N/ -157.115829W*], Gar. & Berg. (?), 30 Jun 1977, 1♂ [UAM]; Holitna River (UAM No. 50457), [61.635231N/ -157.115829*], Gar. & Berg. (?), 17 Jul 1977, 1♂ [UAM]; North Slope Co., Umiat, small rock bottomed stream, elev. 352’ (PERC No. 0064686), [69.367277N/ -152.1416W*], C.M. White, 17 Jun 1964, 15N, [PERC]; SWEDEN: Abisko (estimated site edge of lake at Abisko–PERC No. 0064687) [68.354888N/ 18.840431E], Thienemann ? Jun 1936, 3N, 1Nex, [PERC].

Parameletus columbiae McDunnough, 1938
Material Examined. Holotype, CANADA: British Columbia: Thompson-Nicola Co., Dunn Peak, North Thompson River, swarm over small glacial stream at 7000 ft. elev., (CNC No. 4289) [51.441757N/ -119.954675W*], J.K. Jacob, 10 Aug 1937, 1♂ [CNC].
Other Material StudiedUSA: Alaska: Fairbanks North Star Co., Chatanika River, 0.8 miles below x-ing (13:00–14:00 hr.) sample C-B (UAM No. 50485) [65.081917N/ -147.734134W*], 12 Apr 1978, 3N [UAM]; Chena River, C-750, Qual. (UAM No. 50456) [64.848259N/ -147.383583W*], Sch. & Jin. (?), 8 May 1972, 20N [UAM]; Chena River, C-800, Qual. (UAM No. 50454) [64.848259N/ -147.383583W*], Sch. & Jin. (?), 8 May 1972, 1N [UAM]; Chena River, C-725, Qual. (UAM No. 50452) [64.848259N/ -147.383583W], Sch. & Jin.(?), 8 May 1972, 20N [UAM]; Bethel Co., Holitna River (UAM No. 50461a)  [61.635231N/ -157.115829W*], Gar. & Berg. (?), 26 Jun 1977, 1♂ [UAM];  Holitna River (UAM No. 50460) [61.635231N/ -157.115829W*], Gar. & Berg. (?), 29 Jun 1977, 1♂ [UAM]; Holitna River (UAM No. 50459) [61.635231N/ -157.115829W*], Gar. & Berg. (?), 19–20 Jun 1976, 1♀ [UAM]; Idaho: Latah Co., 6 mi. north of Harvard (PERC No. 0064689) [46.982101N/ -116.670398W], G.B. White, 12 Jun 1964, 31♀ [PERC]; same, (PERC No. 0064688), same, 11♀ [PERC]; Montana: Flathead Co., Temporary pond at Nyack [48.439617N/ -113.804938W*], S. Chilcote, 13 Jun 2002, 5N [FLBS]; Small stream N. of 2-Lakes Creek, Gunsight Lake Trail, Glacier National Park       [48.655035N/ -113.662708W*], N.P. Colager (?), 19 Jul 1997, 7♂, 4♀ [FLBS]; Utah: Salt Lake Co., Brighton, Silver Lake [40.603466N/ -111.588268W*], G.F. Edmunds Jr., 2 Jun 1947, 3N [FAMU]; same  (ILNHS No. 12373), 23 Jun 1947, 1♂ [ILNHS]; same (ILNHS No. 12373), 2 Jun 1947, 17N [ILNHS].

Parameletus croesus (McDunnough, 1923)
Material Examined. HolotypeCANADA: Ontario: Ottawa Division, Ottawa (CNC No. 522) [45.389755N -75.711848W*], J.H. McDunnough, 22 May 1922, 1♂ [CNC].
Other Material StudiedUSA: Minnesota: Pine Co., St. Croix River, at ferry between Pine City, MN and Grantsburg, WI [45.823431N/ -92.764246W], R.H. Daggy, 26 May 1939, 8♂ [UMN]; Wisconsin: Marinette Co., Menominee River, right bank, about 85ft dnstr. from Hwy JJ bridge and ~2.9 miles dnstr. of Grand Rapids Dam [45.325784N/ -87.663235W*], S. Rheaume, 23 May 1995, 2N [USGS-NAWQA]; same, B. O’Donnell, 13 May 2007, 8N [NEL]; Burnette Co., St. Croix River, Seven Islands, 0–3ft. depth, swift, sand, & gravel [45.83979N/ -92.750617W*], R.A. Lillie, 6 May 1992, 1N [WDNR]; same, St. Croix River, Seven Islands, drop-off, sand, rock, debris, 12492018 (PERC No. 0064690), same, 1N [PERC]; Outagamie Co., Wolf River, Shiocton, below Hwy  54 [44.44283N/ -88.588162W*], R.A. Lillie, 6 May 1993, 1N [WDNR]; same, 011994047-89 (PERC No. 0064685) same, 7N [PERC].

Parameletus midas (McDunnough, 1923)
Material Examined. Holotype, CANADA: Ontario: Ottawa Division, Ottawa (CNC No. 523), [45.389755N -75.711848W*], J.H. McDunnough, 29 May 1922, 1♂ [CNC]; Paratype, Ontario, Ottawa Division, Ottawa (CNC No. 523) [45.389755N/ -75.711848W*], J.H. McDunnough, 29 May 1922, 1♂ [CNC].
Other Material StudiedCANADA: New Brunswick: Gloucester Co., Nepisquit River, Hwy 360 (Middle Landing)  [47.440943N/ -65.705252W*], B. Kondratieff & R. Bauman, 17 Jun 1993, 1♂ [CSU]; Newfoundland (Labrador): Minipi Drainage, L4 [52.604899N/ -61.162381W*], D. Larson & D. Butt, 26 Jun 1983, 3N [NEL]; same, 28 Jun 1983, 2N [NEL]; Quebec: Minganic, Côte-Nord Region, Thunder River (Rivière-au-Tonnerre)[50.28091N/ -64.74834W*], W.J. Brown, 16 May 1930, 3♂ [CNC]; same, 19 Jun 1930, 4♂(reared), 4♀ [CNC]; same, 19 Jun 1930, 5♂ [CNC]; same, 19 Jun 1930, 8Nex [CNC]; same, 21 Jun 1930, 1♂ [CNC]; same, 23 Jun 1930, 5♂ [CNC]; Saquenay, Rivière Pigou, above Tr. 138, elev. 075 ft AMSL [50.2825N/ -65.641944W], D.H. Funk, 6 Jul 1984, 1S♂, 1Nex [SWRC]; USA: Maine: Aroostook Co., Machias River, Site 26 [46.5348N/ -68.6128W],  M. Duron & M. Neal, 29 May 2004, 1N [MEIFW]; Machias River, sedge meadow within 1 mile below Grassy Landing (T10 R7 Wels/ T11 R7 Wels) [46.557908N/ -68.592197W], B. Swartz,  8 Jun 2005, 1N [MEIFW]; Franklin Co., South Branch Dead River, Eustis (UTM 19T 0384938 5001167)  [45.154645N/ -70.463786W], M. Seibenmann, 3 Jun 2009, 11N [NEL]; South Branch Dead River, Eustis, cove on north shore nr. Cove Brk., north of Stratton, elev. 351 m [45.154583N/ -70.463767W], S.K. Burian, 30 May 2008, 1S♂,3 S♀, 2Nex [NEL]; same, 30 May 2008, 20♂,28♀, 7S♂, 11 S♀ 13N, 61Nex [NEL]; Washington Co., Narraguagus River, Rt. 9 [44.842212N/ -68.069674W*], B. Kondratieff & R. Bauman, 2 Jun 1998, 1♂ [CSU].

Identification Key

Systematic Accounts

Parameletus chelifer Bengtsson, 1908

Parameletus columbiae McDunnough, 1938

Parameletus croesus (McDunnough, 1923)

Parameletus midas (McDunnough, 1923)


I am grateful to the following people that generously contributed specimens for this study: Donna Giberson (UPEI, retired), Boris Kondratieff (CSU), Brigid O’Donnell (PSU), Jan Peters (FAMU), Edward DeWalt (INHS), Marcia Seibenmann (Aquatic Biologist-ME), Owen Lonsdale (CNC), Derek Sikes (Univ. Alaska–Museum of the North), Philip Clausen (UMN), Richard Lillie (WI-DNR, retired), Robert Dubois (WI-DNR), Beth Swartz (ME Inland Fisheries & Wildlife), David Funk (SWRC), Robert Hood (USGS–NAWQA Voucher Collection), Tom Bansak (FLBS), Heather Proctor (University of Alberta, Strickland Museum), Gino Nearns (PERC), and David Larson (MU- Newfoundland, retired).


Bauerfeind, E. and T. Soldan. 2012. The Mayflies of Europe (Ephemeroptera). Apollo Books, Ollerup, Denmark. 781 pp.

Bengtsson, S. 1908. Berättelse öfver en resa i entomologiskt syfte till mellersta Sverige Sommaren 1907. K. Svenska Vetenskapsakademiens Årsbok [K. Svenska Vetensk. Akad. Årsb.] 6: 237–246.

Brinck, P. 1957. Reproductive system and mating in Ephemeroptera. Opuscula Entomol. 22: 1 –37.

Burian, S.K. 1995. Taxonomy of the eastern Nearctic species of Choroterpes Eaton (Ephemeroptera: Leptophlebiidae). p.433–453. In Corkum, L.D. and J.H. Ciborowski (eds.). Current Directions in Research on Ephemeroptera. Canadian Scholars’ Press Inc. Toronto.

Burian, S.K. 2001. Revision of the genus Leptophlebia Westwood in North America (Ephemeroptera: Leptophlebiidae: Leptophlebiinae). Ohio Biological Survey N.S. Vol. 13(3): vi+80p.

Daggy, R.H. 1941. Taxonomic and biologic investigations on Minnesota mayflies Ephemeroptera). Ph.D. dissertation, University of Minnesota, p. 331, plates 1–22.

Edmunds, G.F., Jr. 1952. Studies on the Ephemeroptera: I. The Phylogeny and classification of the Ephemeroptera, with a study of flight mechanics and evolution of their wings; II The taxonomy and biology of the mayflies of Utah. Ph.D. Dissertation, University of Massachusetts, Amherst, 399 p. + 22 plates.

Edmunds, G.F., Jr. 1957. On the life history of Parameletus columbiae McDunnough (Ephemeroptera). Uath Academy Proceedings 34: 25–26.

Edmunds, G.F., Jr., S.L. Jensen, and L. Berner 1976. The Mayflies of North and Central America. University Minnesota Press, Minneapolis. 330 pp.

Esben-Petersen, P. 1916. Ephemerida, Scientific results of the expedition of the Kuznetsov brothers to the Polar Urals in 1909, under command of H. Backlund. Memoirs of the Imperial Academy of Sciences, Series 8, Section of Physics and Mathematics, St. Petersburg, Vol 28, No. 12: 1–12.

Giberson, D.J., S.K. Burian, and M. Shouldice. 2007. Life history of the northern mayfly Baetis bundyae in Rankin Inlet, Nunavut, Canada, with updates to the list ofmayflies of Nunavut. Can. Entomol. 139: 628–642.

Gilpin, B.R. and M.A. Brusven. 1970. Food habits and ecology of mayflies of the St. Maries River, Idaho. Melanderia (Washington State Entomological Society) 4: 19–40.

Harper, F. and P.P. Harper 1981. Northern Canadian mayflies (Insecta; Ephemeroptera), records and descriptions. Can. J. Zool. 59: 1784–1789.

Harper, P.P. and F. Harper. 1997. Mayflies (Ephemeroptera) of the Yukon. In Danks, H.V. and J.A. Downs (eds.). Insects of the Yukon. Biological Survey of Canada (Terrestrial Arthropods), Canadian Museum of Nature, Ottawa.

Hubbard, M.D., 1977. The validity of the generic name Parameletus Bengtsson (Ephemeroptera: Siphlonuridae). Proc. Entomol. Soc. Wash. 79: 409–410.

Hubbard, M.D. 1995. Toward a standard methodology for the description of mayflies (Ephemeroptera), p. 361–369. In Corkum, L.D. and J.J.H Ciborowski (eds.), Current Directions in Research on Ephemeroptera, Canadian Scholars Press, Toronto.

Jensen, S.L. 1966. The mayflies of Idaho (Ephemeroptera). M.S. Thesis, University of Utah, Salt Lake City, p. 365.

Jacobus, L.M. and W.P. McCafferty. 2002. Analysis of some unfamiliar Canadian mayflies (Ephemeroptera). Can. Entomol. 134: 141–155.

Jacobus, L.M., N.A. Wiersema, and J.M. Webb. 2014. Identification of far northern and western North American mayfly larvae (Insecta: Ephemeroptera), north of Mexico, Joint Aquatic Sciences meeting, Portland, OR, USA, p 176+ suppl., unpublished workshop manual [pdf available from L.M. Jacobus (]

Kjærstad, G., J.M. Webb, and T. Ekrem. 2012. A review of the Ephemeroptera of Finnmark –DNA barcodes identify Holarctic relations. Norwegian J. Entomol. 59: 182–195.

Klubertanz, T.H. 2016. Mayfly Larvae of Wisconsin (G4074). University of Wisconsin-Extension, Cooperative Extension, Cooperative Extension Publishing, Madison, WI.

Kluge, N.Ju., 1994. Pterothorax structure of mayflies (Ephemeroptera) and its use in systematics. Bulletin de la Société Entomologique de France 99: 41–61.

Kluge, N.Ju., D. Studemann, P. Landolt, and T. Gonser. 1995. A reclassification of the Siphlonuroidea (Ephemeroptera). Bull. Soc. entomol. Suisse 68: 103–132.

Koss, R.W. 1970. A list of the mayflies (Ephemeroptera) in the Michigan State University Entomology Museum. Michigan Entomol. 3: 98–101.

Lillie, R.A. 1995. A Survey of Rare and Endangered Mayflies of Selected Rivers of Wisconsin. Wisconsin Dept. of Natural Resources Research Report No. 170.

McCafferty, W.P. and R.L. Newell. 2007. Insecta, Ephemeroptera: Range extensions and new state records for far western Montana, USA. Check List 3:260–266.

McCafferty, W.P. and R.P. Randolph. 1998. Canada Mayflies: a faunistic compendium. Proc. Entomol. Soc. Ontario 129: 47–97.

McCafferty, W.P., R.P. Randolph, and L.M. Jacobus. 2012. The Mayflies of the Intermountain West. Memoirs of the American Entomological Institute (Gainesville, Florida) 85: 1–317.

McDunnough, J. 1923. New Canadian Ephemeridae with notes. Can. Entomol. 55: 39–50.

McDunnough, J. 1930. The Ephemeroptera of the north shore of the Gulf of St. Lawrence. Can. Entomol. 62: 54–62.

McDunnough, J. 1938. New species of North American Ephemeroptera with critical notes. Can. Entomol. 70: 23–34.

Newbold, J.D., B.W. Sweeney, and R.L. Vannote. 1994. A model for seasonal synchrony in stream mayflies. J. N. Amer. Benthol. Soc. 13: 3–18.

Newell, R.L. and B.R. Hossack. 2009. Large wetland-associated mayflies (Ephemeroptera) of Glacier National Park, Montana. Western North Amer. Naturalist 69: 335–342.

Olsson, T. and O. Söderstrom. 1978. Springtime migration and growth of Parameletus chelifer (Ephemeroptera) in a temporary stream in northern Sweden. Oikos 31: 284–289.

Peters, J.G. and W.L. Peters. 1995. Evidence for a dispersal morph in females of Dolania americana (Ephemeroptera: Behningiidae). p.253–262 In Corkum, L.D. and J.H. Ciborowski (eds.). Current Directions in Research on Ephemeroptera. Canadian Scholars’ Press Inc. Toronto.

Ruffieux, L. 1997. Réserves énergétiques et strategies de reproduction chez les Ephéméroptères (Insecta, Ephemeroptera). Thèse Doctorat, University of Lausanne, 168 pp.

Scudder, G.G.E. 1975. An annotated checklist of the Ephemeroptera (Insecta) of British Columbia. Syesis 8: 311–315.

Shorthouse, David P. 2010. SimpleMappr, an online tool to produce publication-quality point maps. [Retrieved from Accessed August 26, 2016].

Söderstrom, O. 1988. Effects of temperature and food quality on life-history parameters in Parameletus chelifer and P. minor (Ephemeroptera): a laboratory study. Freshwater Biology 20: 295–303.

Söderstrom, O. and A. Johansson. 1988. Effects of habitat on development, fecundity, and susceptibility to parasites in Parameletus chelifer and Parameletus minor (Ephemeroptera). Can. J. Zool. 66: 2715–2725.

Söderstrom,O. and J. Nilsson. 1986. Redescription of Parameletus chelifer Bengtsson and P. minor (Bengtsson), with keys to nymphal and adult stages of the Fennoscandian species of Siphlonuridae (Ephemeroptera). Entomlogica scandinavica 17: 107–117.

Söderstrom,O. and J. Nilsson. 1987. Do nymphs of Parameletus chelifer and P. minor (Ephemeroptera) reduce mortality from predation by occupying temporary habitats? Oecologia (Berlin) 74: 39–46.

Studemann, D. and I. Tomka. 1991. European Siphlonuridae (Ephemeroptera): a phylogenetic system for the four genera, p. 103–104. In Alba-Tercedor, J. and A. Sanchez-Ortega (eds.), Overview and Strategies of Ephemeroptera and Plecoptera. Sandhill Crane Press, Gainesville, Florida.

Sujeevan, R. and P.N. Hebert. 2007. BOLD: The barcode of life data system ( ).Molecular Ecol. Notes 7: 355-364 [doi:10.111/j.1471–8286.2006.01678x].

Spieth, H.T. 1938. Taxonomic studies on Ephemerida. I: description of new North American species. Am. Mus. Novitates 1002: 1–11.

Traver, J.R. 1935. Part II. North American Mayflies: A systematic account of North American species in both adult and nymphal stages. In Needham, J.G., J.R. Traver, and Y. Hsu. The Biology of Mayflies. Comstock Publishing Co., Ithaca, New York.

Tiunova, T.M. 2008. Two species of Parameletus Bengtsson 1908 (Ephemeroptera: Siphlonuridae) and notes on other species from far east of Russia. Zootaxa 1725: 17–26.

Webb, J.M., L.M. Jacobus, D.H. Funk, X. Zhou, B. Kondratieff, C.J. Geraci, R.E. DeWalt, D.J. Baird, B. Richard, I. Philips, and P.D.N. Hebert. 2012. A DNA barcode library for North American Ephemeroptera: Progress and prospects. PLoS One 7(5): e38063. doi: 10.1371/journal.pone.0038063.

Webb, J.M., D.W. Parker, D.M. Lehmkuhl, and W.P. McCafferty. 2004. Additions and emendations to the mayflies (Ephemeroptera) fauna of Saskatchewan. Entomol. News 115: 213–218.

*Literature cited also includes citations for records listed in Appendix 1 spreadsheet for all previous published records of Nearctic species of Parameletus.


Burian, K. 2017. The Taxonomy of the North American Species of Parameletus Bengtsson, 1908 (Ephemeroptera: Siphlonuridae), with Keys to Nymphs and Male Imagos. Canadian Journal of Arthropod Identification 33: 76pp. doi:10.3752/cjai.2017.33


Appendix 1: Specimen data for Parameletus of North America (.xlsx)