1. EPHEMEROPTERA

2. Two theories of flight

3. 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

4. Phylogeny of the Paleoptera
Entognatha
Sister group to pterygote insects
Hexapoda
Archaeognatha
Thysanura
Insecta
Ephemeroptera
Odonata
Pterygota
Paleoptera
Neoptera

5. 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

6. 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

7. Paleontology of Mayflies
Modern mayflies
Stem families
1) ≈ wings
2) Mouthparts in adults

8. Ephemeroptera - Wings

9. Costal brace

10. Ephemeroptera
Superficially look like Plecoptera (stoneflies) but…
Ephemeroptera
Plecoptera
-abodminal gills thoracic gills

11. -originally terrestrial - then invaded water
Ephemeroptera
-originally terrestrial - then invaded water
-first invade lotic streams
-then radiate to lentic streams

12. Ephemeroptera - Life History
subimago
nymph
Egg laying
imago (adult)
Mating swarm

13. Timing of life stages
December
Nymph
September
Adult
March
June

14. Ephemeroptera - Life History
Nymph
Ecological Specialization
Climbers
Free-ranging
Clinging
Silt
Clinging
Burrowers

15. Ephemeroptera - Life History
Nymph
Scraper
Shredder
Predator
Feeding Mode
Gatherer
Filter feeder

16. Ephemeroptera - Life History
Subimago

17. Ephemeroptera - Life History
Subimago to Adult
add genitalia
wings clear

18. Ephemeroptera - Mating

19. Male
Female in vegetation
Giant Mayfly Mating

21. 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

22. Ephemeroptera - Egg laying

23. • • • • • • • • Ephemeroptera - Egg laying
Hatching is temperature sensitive
100 75 50 25 • • • • •
% eggs hatched • • •
Temperature (ºC)

24. Ephemeroptera as Indicator Species

25. 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