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Insect Order Ephemeroptera (Mayflies)

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Ephemeroptera (Mayflies)

Family in Ephemeroptera
AmeletidaeBrown Duns	0	0
BaetidaeBlue-Winged Olives	0	10
BaetiscidaeArmored Mayflies	0	1
CaenidaeAngler's Curses	0	0
EphemerellidaeHendricksons, Sulphurs, PMDs, BWOs	0	37
EphemeridaeHexes and Big Drakes	0	3
HeptageniidaeMarch Browns, Cahills, Quill Gordons	0	11
IsonychiidaeSlate Drakes	0	0
LeptohyphidaeTricos	0	1
LeptophlebiidaeBlue Quills and Mahogany Duns	0	0
MetretopodidaePseudo-Gray Drakes	0	0
Neoephemeridae	0	0
PolymitarcyidaeWhite Flies	0	0
PotamanthidaeGolden Drakes	0	0
SiphlonuridaeGray Drakes	0	3

8 families aren't included.

Common Name

Match	Common Name
	Mayflies

Pictures Below ↓

This is page 78 of specimens of Ephemeroptera. Visit the main Ephemeroptera page for:

The behavior and habitat of Ephemeroptera.
67 underwater pictures of Ephemeroptera.

Pictures of 828 Mayfly Specimens:

Specimen Page:1...777879...84

Stenacron (Light Cahills) Mayfly Nymph

View 2 Pictures

Collected August 8, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 18, 2006

Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs) Mayfly Nymph

View 3 PicturesThis is a really really really really tiny mayfly nymph. It has gills on abdominal segments 3-7 in the characteristic orientation for the Ephemerellidae family, and it has no fain tail as best I can tell, just uniform tail coverage with small black hairs of equal length. I think this one's too young to identify.

Collected March 10, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 19, 2006

Female Acerpenna pygmaea (Tiny Blue-Winged Olive) Mayfly Spinner

View 3 Pictures

Collected August 1, 2020 from the Henry's Fork of the Snake River in Idaho
Added to Troutnut.com by Troutnut on August 18, 2020

Male Epeorus albertae (Pink Lady) Mayfly Spinner

View 2 Pictures

Collected June 29, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on June 29, 2011

Epeorus deceptivus Mayfly Nymph

View 4 PicturesIdentification notes from the microscope: Gills on segment 1 extend anteriorly below the body, but not all the way to touching; posterolateral spines minor; femora (

The femur of this Isonychia bicolor mayfly spinner is highlighted in red.

Femur: The main segment of an insect's leg close to the body, in between the tibia and the trochanter.) without fuscous macula.

Collected August 4, 2020 from Green Lake Outlet in Idaho
Added to Troutnut.com by Troutnut on August 20, 2020

Male Rhithrogena robusta Mayfly Spinner

View 3 PicturesThese specimens were collected from a mating swarm from the east branch of the North Fork of the Touchet River, upstream from the Bluewood Ski Area turn.It was a sunny warm day, mating swarm as 4-8 ft. above this small stream. Four male spinners were collected.Stream photos were taken.

Collected July 15, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on July 15, 2011

Maccaffertium terminatum Mayfly Nymph

View 1 PicturesThis is a subspecies (Subspecies: Entomologists sometimes further divide a species into distinct groups called subspecies, which have two lower-case words on the end of their scientific name instead of one. The latter is the sub-species name. For example, Maccaffertium mexicanum mexicanum and Maccaffertium mexicanum integrum are two different subspecies of Maccaffertium mexicanum.) M. terminatum terminatum, formerly called Stenonema. Found mostly in larger rivers in western Montana. This is an immature nymph.

Collected November 23, 2005 from the Flathead River-lower in Montana
Added to Troutnut.com by Bnewell on June 26, 2011

Female Baetis tricaudatus (Blue-Winged Olive) Mayfly Spinner

View 5 PicturesThis female spinner was deceased when photographed, so the posture is unnatural, but it was a substantial hatch and clearly worth imitating (with wet flies to imitate the sunken ovipositing females) so I went ahead with the photos.

It was collected in association with a male spinner.

Collected September 4, 2020 from Silver Creek in Idaho
Added to Troutnut.com by Troutnut on September 18, 2020

Male Tricorythodes (Tricos) Mayfly Spinner

View 3 PicturesI collected these males about 9:30 AM, air temp. about 68 degrees F. The males were flying about 3 ft above the stream flying up and down the stream rather than the typical vertical swarm you see with most mayfly males. The males are black and the females are a green color due to the eggs they are carrying. They do not live very long which is typical for small bodied mayflies. They do not fly during windy conditions. I suspect these are Tricorythodes minutus.

Collected August 12, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on August 12, 2011

Attenella margarita (Little Western Blue-Winged Olive) Mayfly Nymph

View 7 PicturesNotes from the microscope on the ID: Maxillary palp (

The palp on the maxilla of an Ephemerella nymph (detached and photographed under a microscope) is highlighted in red here.

Palp: A long, thin, often segmented appendage which can protrude from certain insect mouth parts such as the maxillae. Also known as the < />palpus.) is present, distinctly 2-segmented, but very small. Gills on segment 4-7. This specimen has some unfortunate damage to the abdomen, but it's the only one I found in my sample.

Collected August 3, 2020 from the East Fork Big Lost River in Idaho
Added to Troutnut.com by Troutnut on August 19, 2020

Specimen Page:1...777879...84

Jargon Defined:

Abdomen: The rear and usually the longest (ten-segmented in mayflies) portion of an insect's body, to which the tails are attached.

The femur of this Isonychia bicolor mayfly spinner is highlighted in red.

Femora: The main segment of an insect's leg close to the body, in between the tibia and the trochanter.

Nymph: The juvenile, underwater stages of mayflies, stoneflies, dragonflies, and damselflies and other aquatic insects whose juvenile stages are covered by hard exoskeletons. The word can also refer to the fishing flies which imitate these creatures, in which case it is used as a blanket term for flies imitating any underwater stage of an invertebrate (except for crayfish and leeches).

Ovipositing: To lay eggs.

The palp on the maxilla of an Ephemerella nymph (detached and photographed under a microscope) is highlighted in red here.

Palp: A long, thin, often segmented appendage which can protrude from certain insect mouth parts such as the maxillae. Also known as the < />palpus.

Spinner: There are two winged stages of adult mayflies. They emerge from the water as duns, molt on land (usually) into their fully mature stage, spinners. As spinners, they mate, lay eggs, and die.

Subspecies: Entomologists sometimes further divide a species into distinct groups called subspecies, which have two lower-case words on the end of their scientific name instead of one. The latter is the sub-species name. For example, Maccaffertium mexicanum mexicanum and Maccaffertium mexicanum integrum are two different subspecies of Maccaffertium mexicanum.