Insect Order Ephemeroptera (Mayflies)

This is a pretty clear photo of an Epeorus nymph clinging flat against a log. The big mound of debris on the bottom center of the picture, attached to the light rock, is a structure that's been puzzling me. I've found several in one section of the river. It's big, like 2 inches long and maybe 1/2-3/4 inch wide/tall, and hollow, like some sort of coccoon or something. It's clearly a structure built by some sort of little creature, but I'm not sure what.

In this picture: Mayfly Genus Epeorus (Little Maryatts).

The top of this stump is covered with mayfly and caddisfly life.

In this picture: Insect Order Ephemeroptera (Mayflies) and Insect Order Trichoptera (Caddisflies).

There are a couple Epeorus mayfly nymphs clinging to this rock. One interesting thing I've noticed is that even though the stream has a lot of clingers, they rarely show up in my photos, and I've started paying more attention to the river bottom while I'm fishing I've noticed that clinger nymphs generally see or feel me coming and scurry to the undersides of their rocks before I can get in picture range. I think I have the same problem with stoneflies.

In this picture: Mayfly Genus Epeorus (Little Maryatts).

Several well-camouflaged Ephemerella mayfly nymphs cling to this log, and a few cased caddisfly larvae cling to the plant in front of it.

In this picture: Insect Order Trichoptera (Caddisflies) and Mayfly Genus Ephemerella (Hendricksons, Sulphurs, PMDs).

This is a close-up underwater view of a stillborn (

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This stillborn Ephemerella subvaria dun is trapped in its shuck.

Stillborn: In fly fishing, a stillborn insect is one which got stuck in its nymphal or pupal shuck during emergence and floats helplessly on the surface instead of flying away. It is a specific class of cripple, although it is sometimes used interchangeably with that term.) Ephemerella subvaria (Henrickson) female dun.

In this picture: Mayfly Species Ephemerella subvaria (Hendrickson).

Here's the surface of the river viewed from below during a Tricorythodes spinner fall. Several dead spinners are visible.

In this picture: Mayfly Genus Tricorythodes (Tricos).

An Ephemerella subvaria nymph clings to a white rock in the foreground, and there are other nymphs in the background.

In this picture: Mayfly Species Ephemerella subvaria (Hendrickson) and Insect Order Trichoptera (Caddisflies).

Several fast-swimming Siphlonurus nymphs blend in very well with the silt in this slow backwater along a trout stream.

In this picture: Mayfly Genus Siphlonurus (Gray Drakes).