Animal Phylum Arthropoda (Arthropods)

This Epeorus pleuralis nymph tried to hatch into a dun while attached to this rock and apparently got stuck. This species is supposed to emerge from its nymphal shuck (

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Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.

Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.) on the bottom of the stream and swim to the surface as a bedraggled dun. It seems more like this one was trying to crawl out onto a rock to emerge. The rock itself is covered with a thin layer of fast water in a riffle, and apparently it prevented the dun from making any headway. You can see the dun's eyes and a bit of the mesonotum (Mesonotum: The top of the insect mesothorax.) if you look closely.

In this picture: Mayfly Species Epeorus pleuralis (Quill Gordon).

A thick mating swarm of Tricorythodes mayfly spinners hovers over a cool Catskill tailwater one early fall morning. View the picture full-size and you'll be able to make out the wings and tails on most of those little white dots.

This was one of many such clouds visible all up and down the river. The mayflies were impressive, but the trout did not hold up their end of the bargain -- there was not a rise in sight.

In this picture: Mayfly Genus Tricorythodes (Tricos).

Often mayflies can be found on houses near the river. This one molted from a dun into a spinner on the outside of our kitchen window.

Any lit dwelling near the river can attract a lot of mayflies at night. A good way to determine what's hatching is to visit a gas station (or anything else with bright lights) close to the river early in the morning.

In this picture: Mayfly Family Baetidae (Blue-Winged Olives).

This is my favorite underwater picture so far. It shows a bunch of Simuliidae (black fly) larvae clinging to a rock and swinging in the fast current. There are also at least four visible mayfly nymphs, probably in the family Baetidae.

In this picture: Mayfly Family Baetidae (Blue-Winged Olives) and True Fly Family Simuliidae (Black Flies).

Hundreds of cased caddisfly larvae live on this log in a small brook trout stream.

In this picture: Insect Order Trichoptera (Caddisflies).

This Ephemerella subvaria (Hendrickson) nymph picture is one of my favorites.

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