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Mayfly nymph, Heptageniidae

Mayfly nymph, Heptageniidae
North Bear Creek, Winneshiek County, Iowa, USA
September 28, 2014
Size: 5mm
The specimen was found under a rock in North Bear Creek. Several of this type were found but this was one of the largest. It has three tails.

Maccaffertium and likely vicarium based on the shovel shaped head the orange unbanded tails and the black transverse band crossing over the 10th tergite.

Moved from Mayflies.

Hi Robert-

Katie has correctly identified this mayfly nymph as being a of family Heptageniidae, and I further suspect it to be of genus Maccaffertium.

Moved from ID Request.

Family Heptageniidae
Looks to be in the mayfly family Heptageniidae: