Mayfly Genus Heptagenia
6 species aren't included.
This is page 2 of specimens of Heptagenia. Visit the main Heptagenia page for:
- The behavior and habitat of Heptagenia.
Pictures of 11 Mayfly Specimens in the Genus Heptagenia:
Male Heptagenia culacantha Mayfly Spinner
View 1 PicturesThis photo was provided by guide Eric Naguski along with the following comments, "I took this photo just upstream of Three Mile Island on the east shore of the Susquehanna River just below where the Swatara Creek enters. The Susquehanna is not an easy river to sample for bugs in my opinion. It is very large and pushes a lot of water. Especially in the spring when you would collect mature culacantha nymphs. And I don't believe that there are a ton of these Heptageniids around. Also the people who are doing most of the sampling like myself are doing so for water quality monitoring work so they only take the specimens down to genus-level taxonomy". Heptagenia 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.