EPHEMEROPTERA
Two theories of flight
Hexapoda Insecta Pterygota Neoptera Holometabola Apterygotes Entognatha Archaeognatha Hexapoda Zygentoma = Thysanura Ephemeroptera Insecta Odonata Plecoptera Embiodea Pterygota Zoraptera Dermaptera Grylloblattodea ? Mantophasmatodea Orthoptera Phasmatodea Blattaria Isoptera Mantodea Neoptera Psocoptera Phthiraptera Thysanoptera Hemiptera Coleoptera Rhaphidioptera Megaloptera Neuroptera Hymenoptera Holometabola Mecoptera Siphonaptera Diptera Apterygotes Strepsiptera Trichoptera Paleoptera Lepidoptera Hemimetabolous Holometabolous
Phylogeny of the Paleoptera Entognatha Sister group to pterygote insects Hexapoda Archaeognatha Thysanura Insecta Ephemeroptera Odonata Pterygota Paleoptera Neoptera
Phylogeny of the Paleoptera Thysanura Insecta Ephemeroptera Odonata Pterygota 1) Subimago stage Paleoptera 2) Costal brace Neoptera 1) Axillary sclerite doesn’t permit wing folding 1) No abdominal appendages in adult 2) No wings
Hexapod Orders Ephemeroptera Ephemero - short-lived, ptera - wings Number of Species ca. 2000 Common names mayflies, shadflies Typical habitats Nymphs - aquatic, Adult - aerial Distinguishing characteristics -three tails (cerci) -non-foldable wings Other features -short lived -don’t feed as adults – no mouthparts
Paleontology of Mayflies Modern mayflies Stem families 1) ≈ wings 2) Mouthparts in adults
Ephemeroptera - Wings
Costal brace
Ephemeroptera Superficially look like Plecoptera (stoneflies) but… Ephemeroptera Plecoptera -abodminal gills -thoracic gills
-originally terrestrial - then invaded water Ephemeroptera -originally terrestrial - then invaded water -first invade lotic streams -then radiate to lentic streams
Ephemeroptera - Life History subimago nymph Egg laying imago (adult) Mating swarm
Timing of life stages December Nymph September Adult March June
Ephemeroptera - Life History Nymph Ecological Specialization Climbers Free-ranging Clinging Silt Clinging Burrowers
Ephemeroptera - Life History Nymph Scraper Shredder Predator Feeding Mode Gatherer Filter feeder
Ephemeroptera - Life History Subimago
Ephemeroptera - Life History Subimago to Adult add genitalia wings clear
Ephemeroptera - Mating
Male Female in vegetation Giant Mayfly Mating
Ephemeroptera - Egg laying Females lay eggs by: 1) Dropping on surface while flying 2) Place on stones underwater 3) Spread underwater 4) Rupture female’s body
Ephemeroptera - Egg laying
• • • • • • • • Ephemeroptera - Egg laying Hatching is temperature sensitive 100 75 50 25 • • • • • % eggs hatched • • • 5 10 15 20 Temperature (ºC)
Ephemeroptera as Indicator Species
Ephemeroptera as Indicator Species General habitat Feeding pH Oxygen % Trophic level Baetis vagans gravel, streams scraper ≥7 100 Oligo Epeorus vitreus shredder >7 Ephemera simulans sand, gravel, lakes, streams predator, gatherer, shredder 50-100 Meso-Oligo Ephemerella subvaria approx. 7 Ephemerella cornuta Heptagenia flavescens wood, rock, streams shredder, gatherer ? Meso-Eutro Hexagenia limbata mud, lakes predator ≅100 Hexagenia recurvata mud, cold streams Isonychia bicolor swimmer, streams filter feeder Paraleptophlebia debilis gravel, rocks, streams gatherer, shredder Dyst-Oligo Rhithrogena undulata gatherer Stenacron interpunctatum rocks, lakes, streams, ponds gatherer, scraper <7 - >7 25-100 all levels Stenonema tripunctatum rocks, streams ≥7 - >7 Stenonema femoratum Tricorythodes minutus indifferent, streams only Meso, Dyst