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Order Ephemeroptera - Mayflies

Big-Eyed Mayfly Nymph - Stenacron interpunctatum Mayfly - Siphloplecton mayfly - Anthopotamus myops Mayfly Sp. - Hexagenia mayfly - Callibaetis fluctuans Siphlonuridae? - Ameletus Leucrocuta sp.? - Leucrocuta Callibaetis? - Callibaetis floridanus
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Ephemeroptera (Mayflies)
Other Common Names
in angling/flyfishing, an adult mayfly (imago) is called a spinner; the winged pre-adult (subimago) is called a dun; and many species have common names(1)
Synonyms and other taxonomic changes
The classification/nomenclature in the Guide generally follows Mayfly Central(2)
Explanation of Names
Greek ephemeros 'of/for a day; short-lived' + pteron 'wing' -- refers to the short-lived adults ["ephemeros" comes from epi 'upon' + hemera 'day']
MAYFLY: adults appear in large numbers in May
611 spp. in 59 genera of 21 families in our area(3); worldwide, ~3350 spp. in >440 genera of at least 42 families(4)(5); 300 spp. in se. US(6), 204 in the Carolinas(7)(8), 71 in FL(9)
Genera not yet in the Guide are listed in(10)
Overview of our fauna (* –taxa not yet in the guide)
Order Ephemeroptera


Infraorder PANNOTA
Superfamily Caenoidea
Superfamily Ephemerelloidea

Superfamily Ephemeroidea
Superfamily *Euthyplocioidea
Superfamily Potamanthoidea
Superfamily Heptagenioidea
1-30 mm(3)
Adult (imago): body delicate or "flimsy", varying from almost transparent to white, yellow, orange, green, brown, or black; thorax and abdomen bare, often shiny; legs slender, solid color; front legs often held forward and sometimes upward in front of head when at rest; forewings large, triangular, with many cross veins; hindwings much smaller than forewings (hindwings absent in some species); both wings usually transparent but sometimes patterned, held vertically and together above thorax when at rest
Pre-adult (subimago): wings cloudy in appearance, body dull and pubescent, with appendages somewhat shorter -- but otherwise similar to imago; pre-adults molt a final time to become adults
Nymph (usually called larva in mayflies): body elongate, flattened or cylindrical, usually greenish or brownish but color varies according to the type of food eaten; legs long; antennae short; abdomen with lateral plate-like gills and usually three long thin tail projections (cerci); some species have only two cerci
Very detailed general info in(9)
keys: NA, genera, larvae & adults(11); ne. NA, genera, nymphs(12); Upper Midwest, families, nymphs(13); Florida, nymphs(14); California(15)
local guides/keys(16)(17)(18)(19)(20)(21)
worldwide and throughout NA; for ranges of nearctic spp., see(22)(2)(23)
most nymphs develop in streams and rivers that are well-oxygenated and relatively free of pollution; some species develop in lakes or ponds, usually in shallow water where the oxygen content is highest
adults may be found on vegetation near water, and are attracted to lights
some emerge in late April (earlier in the south) but the greatest numbers first appear in May, and adults may be seen until September in the north; later, and perhaps around the year, in the far south
nymphs feed on pieces of organic matter such as plant material or algae and debris that accumulates on rocks or other substrates in flowing water (predation recorded in some)
adults have no functional mouthparts and do not feed
Life Cycle
Mating and oviposition. Adult males gather in mid-air swarms, usually 5-15 metres above the ground; females fly into the swarm, and mating occurs in flight. Females deposit eggs while flying low over the water, or by dipping the abdomen into the water; some species submerge themselves and lay eggs underwater.
Development. Mayflies are hemimetabolous, that is, they undergo incomplete metamorphosis, a form of simple metamorphosis, and represent the only insect group whose members molt in winged condition. Nymphs (or naiads) develop through several (perhaps dozens) stages (instars) by molting. The number of molts varies depending on species, temperature, and water conditions. Mature nymphs swim to water surface or crawl onto rocks or plants, then molt into winged subadults (subimagos) which fly to nearby plants and molt again into adults (called imagoes). Adult lifespan ranges from 1.5 hours to two weeks; most adults live 48-72 hrs.
Adults and nymphs are an important source of food for fish and other aquatic wildlife. Anglers often use mayflies as bait.
See Also
stonefly and caddisfly adults hold their wings together horizontally over the abdomen, and hugged closed to the body
stonefly nymphs have filamentous gills (not plate-like), and usually have two cerci (not three)
Print References
Internet References
Works Cited
1.Neuswanger J. (2004-2014) Aquatic insects of American trout streams
2.Mayfly Central
3.American Insects: A Handbook of the Insects of America North of Mexico
Ross H. Arnett. 2000. CRC Press.
4.Barber-James H., Sartori M., Gattolliat J-L., Webb J. (2013) World checklist of freshwater Ephemeroptera species
5.Global diversity of mayflies (Ephemeroptera, Insecta) in freshwater
Barber-James, H.M., Gattolliat, J.L., Sartori, M. & Hubbard, M.D. 2008. Hydrobiologia, 595: 339–350.
6.The mayflies (Ephemeroptera) of the southeastern United States
Mccafferty W.P., Lenat D.R., Jacobus L.M., Meyer M.D. 2010. Trans. Am. Ent. Soc. 136: 221-233.
7.Mayflies (Ephemeroptera) of North Carolina and South Carolina: An update
M.L. Pescador, D.R. Lenat, M.D. Hubbard. 1999. Florida Entomologist 82(2): 316-332.
8.The Ephemeroptera of North Carolina: A biologist’s handbook with standard taxonomic effort levels. Version 3.3
S.R. Beaty. 2011. North Carolina Department of Environment and Natural Resources. 48 + 9 pp.
9.The Mayflies of Florida: Revised edition
Berner L., Pescador M.L. 1988. University Presses of Florida. 431 pp.
10.Aquatic Orders Wish List
11.Aquatic Insects of North America
R. W. Merritt, K. W. Cummins, M.B. Berg. 2008. Kendall/Hunt.
12.Freshwater macroinvertebrates of Northeastern North America
Peckarsky, B. L., P. Fraissinet, M. A. Penton, and D. J. Conklin, Jr. 1990. Cornell University Press, Ithaca, NY.
13.Guide to aquatic macroinvertebrates of the Upper Midwest
Bouchard R.W., Jr. 2004. Water Resources Center, U. of Minnesota, St. Paul, MN. 208 pp.
14.Guide to the mayfly (Ephemeroptera) nymphs of Florida
Pescador M.L., Richard B.A. 2004. Dept Envir. Prot., Div. Water Resource Management, Tallahassee. 168 pp.
15.Aquatic Insects of California
Robert L. Usinger, Editor. 1956. University of California Press.
16.Bright E. (2002-2011) Aquatic Insects of Michigan
17.Clifford H.F. (1991) Aquatic invertebrates of Alberta
18.Ziser S.W. (2008-2012) The aquatic invertebrates of Texas
19.Digital key to aquatic insects of North Dakota
20.Hadden J. (2010) Upper Delaware River insect identification - Photos and Biology of Aquatic Insects - Mayfly Section
22.Rohrbeck R. (2004-2014) Flyfishing entomology
23.Kondratieff B.C., ed. (2000-) Mayflies of the United States
24.Ephemeroptera of South America (Aquatic Biodiversity of Latin America Series, Vol. 2.)
Dominguez E., Molineri C., Pescador M.L., Hubbard M.D., Nieto C. 2006. Pensoft Publishers. 646 pp.
25.The mayflies of Europe (Ephemeroptera)
Bauernfeind E., Soldán T. 2012. Brill Academic Publishers. 781 pp.
26.Ephemeroptera Galactica, the ephemeropterists' home page