Trout Streams

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Wisconsin

> The Namekagon River

Some large Ephemerella mayfly nymphs cling to a log. In the background, hundreds of Simuliidae black fly larvae swing in large clusters in the current.

In this picture: Mayfly Species Ephemerella subvaria (Hendrickson), True Fly Family Simuliidae (Black Flies), and Mayfly Species Ephemerella invaria (Sulphur Dun).

Three big Ephemerella subvaria mayfly nymphs share a rock with some cased caddis larvae.

In this picture: Mayfly Species Ephemerella subvaria (Hendrickson) and Saddle-case Maker Genus Glossosoma (Little Brown Short-horned Sedges).

The white blotches on this rock are Leucotrichia caddisfly cases, and the wispy tubes are cases made by a type of midge.

In this picture: Mayfly Species Ephemerella invaria (Sulphur Dun), Caddisfly Species Leucotrichia pictipes (Ring Horn Microcaddis), and True Fly Family Chironomidae (Midges).

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

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

There's a stonefly nymph in the bottom right corner of this picture, but what's really interesting is those white blotches. They're pretty common in my Wisconsin home river river, stuck flat onto the rocks--lots of rocks have a speckled look as a result. They are microcaddis cases, made by larvae of the caddisfly family Hydroptilidae. These are made by larvae of the subfamily Leucotrichiinae, most likely the genus Leucotrichia. They spin little flat oval cases of silk tight and immobile against the rocks.

In this picture: Caddisfly Species Leucotrichia pictipes (Ring Horn Microcaddis).

I took this picture of the underside of a large slab of ice in a northern Wisconsin river in early February. I got cold.

The mayfly and stonefly nymphs in this picture blend in extremely well.

In this picture: Mayfly Species Ephemerella invaria (Sulphur Dun) and Insect Order Plecoptera (Stoneflies).