Upper Delaware river insects, Drunella cornuta, Blue Winged Olive, insect identification fly fishing.
Aquatic insect, Drunella cornuta, Blue Winged Olive, insect identification, Delaware, river, fly fishing, identification, mayflies, caddisflies, stoneflies.
Drunella cornuta

Pronounced - dru nell uh - cor new tuh

Common Name - Blue Winged Olive

Hook - 14, 16
Millimeter - 8 to 10

Body Color - Brown Olive
Tails - 3

Body Color - Yellowish Olive
Wing Color - Medium Dark Dun
Tails - 3

Body Color - Dark Brown Olive
Wing Color - Clear
Tails - 3

   Cornuta nymphs prefer medium to fast moving riffles where the substrate consists of gravel and rocks. Drunella cornuta is a very tricky hatch, due to the color of this insect during emergence. As cornuta nymphs split their husk the freshly hatched duns appear very pale green in color, and continue to grow darker as they drift along the waters surface. Looking closely at floating duns will reveal colors from very pale olive, yellowish olive, tanish olive, to dark olive. This adds complexity to consistently hooking rising trout, as the fish not only lock into one color to feed on, but seem to change color preference as the hatch progresses. The angler fishing this hatch should be well prepared with all of these color variations. Hatches occur in the morning between 8:30 AM and noon, but on cooler rainy days may be found on the water into the afternoon along with Drunella cornutella.

Jerry Hadden's Guide Service

Fly fishing float trips for wild trout on the Upper Delaware River.


Delaware River fly fishing with Jerry Hadden.