EPHEMEROPTERA Ephemeroptera websites Mayfly Central https www entm

EPHEMEROPTERA

Ephemeroptera websites �Mayfly Central = https: //www. entm. purdue. edu/mayfly/ �Mc. Cafferty, W. P. 1996. The mayflies (Ephemeroptera) of North America online. Entomological News 107(1): 61 -63 �Maintained by Purdue University �Includes continuously updated list of North American mayfly taxa �Ephemeroptera Galactica = http: //www. ephemeroptera-galactica. com/ Maintained by Florida A & M University �Includes information for mayfly scientists

The Mayfly Newsletter �Free �Issued two times each year �Dr. Peter M. Grant, Editor Department of Biological Sciences Southwestern Oklahoma State Univ. Weatherford, OK 73096 -3098

Mayfly Species Diversity � 3, 436 spp. known worldwide � 631 spp. known in North America

Modified Hemimetabolous Development �Egg �Larva �Subimago (“dun”) �Imago (adult, “spinner”)

Eggs �Up to 4, 000/female �Oviposition in freshwater �Except Callibaetis, Cloeon - ovoviviparous �Laid �On water surface (touching or resting) �Below water surface (few Baetis spp. ) �From air (few spp. ) �Development time variable �Usually few weeks �Diapause possible for 3 -11 months �Egg hatch triggered by particular warming temperature, generally after required cooling experience

Larvae � 12– 45 molts �Chewing mouthparts always functional �Gills absent in instars 1 and 2, maybe absent in instars 3 and 4 �Variable median caudal filament (i. e. , 2– 3 “tails”)

Larval Body Forms �Burrowers (e. g. , Ephemeridae) �Flattened (e. g. , Heptageniidae) �Fusiform (e. g. , Baetidae)

Burrowers �Ephemeridae, Polymitarcyidae, Palingeniidae, Potamanthidae �Frontal process and mandibular tusks (rami) loosen sediment �Digging legs � Forelegs push sediment aside � Hind legs push sediment backward �Gills feathery �Collectors-gatherers while digging �Collectors-filterers while pumping water through burrow �Some Ephemera predatory

Flattened Body �Usually beneath/between rocks, on top if gills form disc �Shape allows � Movement among rocks, resistance to predation (Heptageniidae, some Ephemerellidae, some Leptophlebiidae) � Camouflage on wood (Neoephemeridae) � Living on fine sediments (Caenidae, Baetiscidae, Tricorythidae)

Fusiform Body �Baetidae, Siphlonuridae, Ameletidae, Metretopodidae, Isonychiidae, some Ephemerellidae, some Leptophlebiidae �Offers least resistant to fluids �Permits more efficient swimming �Typically collectorsgatherers, some collectorsfilterers

Habits �Swimmers (e. g. , Baetidae) �Clingers (e. g. , Leptohyphidae) �Climbers (e. g. , Siphlonuridae) �Burrowers (e. g. , Ephemeridae) �Sprawlers (e. g. , Caenidae)

Habitats �Wide variety: lotic-erosional, lotic-depositional, lentic, some estuarine �Greatest species diversity in rocky-bottomed, 2 nd– 3 rd order streams �Lentic inhabitants in SE N Amer only few species of Siphlonurus (Siphlonuridae), Baetis and Callibaetis (Baetidae) on vascular hydrophytes, and burrowing Ephemera and Hexagenia (Ephemeridae)

Feeding Strategies �Collectors-gatherers (most common) �Collectors-filterers (e. g. , Isonychia) �Scrapers (e. g. , Heptageniidae) �Predators

Structure and Habitat �Thin, attenuated claws and elongate legs associated with lentic and lotic-depositional habitats �Short, thick claws, often with ventral teeth, and short, thicker legs associated with lotic-erosional habitats �Subapical setae possible mechanoreceptors to detect subtle changes in current velocity �Reduced median caudal filament associated with lotic-erosional habitats �Sprawlers with femora close to body, thinner anteriorly

Larval Gills �Primitively on abdominal segments I–VII �Absent on anterior segments of some derived taxa �Used for respiration by creating current over abdomen �Covered with chloride epithelial cells

Caudal Filaments �Hairs distributed laterally to aid in swimming by flicking up and down �Median caudal filament often reduced in lotic-erosional taxa to reduce drag

Maturation �Completed in few weeks to many months (2 years reported) �Most life-cycles annular, univoltine �Few multivoltine (2– 3 generations/year) �Few semivoltine (1 gen/2 yrs, 3 gens/2 yrs, 2 gens/3 yrs) �Maturation faster in warmer climates, with some species completing entire development in as little as 7 days in AZ (Gray, 1981)

Hatch (Emergence of Subimagoes) �Often coordinated, mass emergence, species-specific time of year, day/night �Gas fills space around pharate subimago c. 1 hr before emergence, other activity normal �Insect floats/swims/climbs to surface, ecdysis at surface in few seconds (5– 15 secs) �Subimago flies to protected substrate, becomes quiet �Completes development in few minutes to 2 days �Sheds subimaginal exuviae, flies away

Subimagoes (“duns”) �Wings dull, grayish, with ciliated hind margins �Body dull �Forelegs relatively short �Caudal filaments somewhat hairy, short, soft, bent �Compound eyes less prominent, dull �Mandibles larger

Imagoes (“spinners”) �Wings glistening, iridescent, with hind margins usually bare �Body glossy �Forelegs much elongated, esp. males �Caudal filaments usually not hairy, typically longer, brittle, straight �Compound eyes prominent, glossy �Mandibles stunted, nonfunctional

Imagoes �Live 90 minutes to several weeks, usually less than 3 days �Only functions – mate, oviposit �Mating in male swarms through which females fly �Size of swarm species specific (small companies to large clouds) �Swarm landmarks (e. g. , margin objects, light/dark backgrounds, white water, slicks, highways) �Mating almost always in flight

Leptophlebiidae Prong-gilled Mayflies �“Fusiform” (but somewhat flattened head) �Gills forked, in tufts, or fringed �Lotic-erosional �Swimmers, clingers �Collectors-gatherers, scrapers

Ephemeridae Common Borrower Mayflies �“Burrowers” �Foretibiae fossorial �Tusks curved upward �Lotic-depositional, lenticdepositional �Burrowers �Collectors-gatherers, collectors-filterers, predators

Baetiscidae Armored Mayflies �Gills beneath prothoracic notum, extending to abdominal segment VI �Lotic-depositional (sand, with detritus) �Sprawlers, clingers �Collectors-gatherers, scrapers

Neoephemeridae Large Square-gill Mayflies �“Fusiform” �Gills of abdominal segment II operculate, fused medially �Mesonotum with lobes �Lotic-depositional �Sprawlers, clingers �Collectors-gatherers

Ephemerellidae Spiny Crawler Mayflies �“Fusiform” �Gills absent from abdominal segment II �Lotic-erosional, loticdepositional, lentic-littoral �Clingers, sprawlers, swimmers �Collectors-gatherers (detritus, algae), some scrapers, shredders-herbivores, shredders-detritivores, predators (rare)

Isonychiidae Brushlegged Mayflies �“Fusiform” �Forelegs with rows of long setae on inner surface �Lotic-erosional �Swimmers, clingers �Collectors-filterers, predators

Heptageniidae Flatheaded Mayflies �“Flattened” �Tibiae and tarsi straight �Claws shorter than tarsi �Lotic-erosional, lenticerosional �Clingers �Scrapers, collectors-gatherers

Ameletidae Comb-mouthed Minnow Mayflies �“Fusiform” �Antennae less than 2 X width of head �Maxillae with pectinate spines �Lotic-erosional, loticdepositional �Swimmers, clingers �Scrapers, collectorsgatherers (detritus, diatoms)

Baetidae Small Minnow Mayflies �“Fusiform” �Antennae 2– 3 X width of head or body pale with some dark abdominal segments �Lotic-erosional, loticdepositional �Swimmers, clingers �Collectors-gatherers, scrapers

Ohio Biological Survey

Siphlonuridae Primitive Minnow Mayflies �“Fusiform” �Antennae less than 2 X width of head �Maxillae without pectinate spines �Lentic �Swimmers, climbers �Collectors-gatherers

Adult Mayfly Structure

Bases of MP 2 + Cu. A strongly divergent Hind wing costal angle acute Forewing A 1 unforked Hind wing costal angle rounded Forewing A 1 forked near margin

Some forewing cubital intercalary veins forked 2 -3 tails Isonychiidae Remnants of purple gills inside bases of front legs Front legs mostly dark, middle and hind legs pale Amelitidae Claws dissimilar Hind wing costa acute Siphlonuridae Claws similar Hind wing costa obtuse

Two tails Forewing A 1 reaching outer margin Hind wings with many marginal intercalaries Forewing with detached marginal intercalaries, often double Hind wings tiny or absent Forewing with 2 pairs of cubital intercalaries

Three tails Large hind wings Fore wing marginal intercalaries detached Fore wing marginal intercalaries attached