"Giant Black Stonefly"
Pteronarcys dorsata
giant stonefly nymph

Largest stonefly nymph indigenous to US.
2".  Found in well-oxygenated streams.  Hide
in bottom rubble, bedrock.  3 year growth cycle.
Hatch May to mid-summer.  Peak hatch in June
usually very early or late in day.  Color varies
from chalky grey to dark brown/black.

Other giant stoneflies: Giant Salmon Fly;
Great Brown Stonefly; Great Stonefly;
Golden Stonefly

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