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Insect Order Ephemeroptera (Mayflies)



Pictures Below

This is page 54 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...535455...84
Penelomax septentrionalis Mayfly NymphPenelomax septentrionalis  Mayfly Nymph View 3 Pictures
Collected May 13, 2007 from the Delaware River in New York
Added to Troutnut.com by Troutnut on May 18, 2007
Female Baetis (Blue-Winged Olives) Mayfly DunFemale Baetis (Blue-Winged Olives) Mayfly Dun View 4 PicturesI'm guessing this specimen is in the genus Acerpenna because of the very sharp costal process (
The costal process of a Baetidae dun.
The costal process of a Baetidae dun.
Costal process: A bump or point sticking up from the front margin of an insect's wing, usually the rear wing of certain mayflies. It is sometimes called a costal projection.
)
on her hind wing. I'm guessing pygmaea because it is the most common species.

Editor note: Not Acerpenna. This is most likely Baetis. See comments on this male specimen for rationale. Also compare with the female specimen associated with it.
Collected July 1, 2005 from the Bois Brule River in Wisconsin
Added to Troutnut.com by Troutnut on April 22, 2006
Ephemerella aurivillii Mayfly NymphEphemerella aurivillii  Mayfly Nymph View 9 PicturesI'm pretty sure this is Ephemerella aurivillii. The body is 11mm long, which rules out most other species, and the hind legs seem to be more than 1.5 times longer than the fore legs -- a key characteristic for this species.

This specimen isn't in the best of shape, as it's missing all three tails, but it's the only one of its species I captured in this sample.
Collected May 6, 2007 from Mongaup Creek in New York
Added to Troutnut.com by Troutnut on May 18, 2007
Male Maccaffertium terminatum Mayfly SpinnerMale Maccaffertium terminatum  Mayfly Spinner View 11 PicturesI positively identified this specimen under a microscope with a good key. It was one of the more common species in a generally light mixed bag of mayflies over a big Catskill tailwater last night.

I swooped this one out of the air while it was mating with a female, so I can be certain about her ID as well.
Collected June 7, 2007 from the West Branch of the Delaware River in New York
Added to Troutnut.com by Troutnut on June 8, 2007
Heptagenia pulla (Golden Dun) Mayfly NymphHeptagenia pulla (Golden Dun) Mayfly Nymph View 11 PicturesThis specimen is interesting because Heptagenia pulla has not been reported from Washington or neighboring states (Saskatchewan is the closest), yet the distinctive key characteristics are clear.

It keys to the genus Heptagenia because the tarsal claw (Tarsal claw: The claws at the tip of the tarsus, on an insect's "foot.") has a single basal (Basal: close to the base; root or beginning) tooth, and the gills on segment 7 have fibrils.

For the species key:
1. The left mandible (Mandible: The paired jaws of an insect which are used for grabbing food, located immediately behind the labrum.) is planate (fairly straight-edged) whereas the right mandible (Mandible: The paired jaws of an insect which are used for grabbing food, located immediately behind the labrum.) is angulate (has one sharp turn on the edge).
2. The labrum (Labrum: The platelike structure forming the roof of the mouth of insects; the upper lip.) is much wider than long.
3. There's a thin light-colored streak lateral (Lateral: To the side.) to the eye on the head.
Collected April 9, 2021 from the Yakima River in Washington
Added to Troutnut.com by Troutnut on April 12, 2021
Specimen Page:1...535455...84
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