Arthropod Class Insecta (Insects)

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).

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).

Cased caddis larvae blanket this section of stream bottom.

In this picture: Insect Order Trichoptera (Caddisflies).

Despite the late date in the season, several caddisfly larvae remain on the rocks in this river.

In this picture: Insect Order Trichoptera (Caddisflies).

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).

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

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