Casemaker caddisfly found at Black Branch.
Photo by Amy Ulland

It’s not every day that you find a parasitic worm and egg strand in a collection net for a stream survey. Our Stream Team discovered a six-inch-long horsehair worm during the first stream monitoring event of the spring season on March 5 at Black Branch, a small tributary of Goose Creek.

Horsehair worms spend the winter in a water source and in the spring they mate. The females then lay strands of eggs (up to two feet in length) in the water.  After about a month these eggs hatch and develop into larvae, which parasitize an appropriate insect host and develop into adults.

The Stream Team was also excited to find a casemaker caddisfly larva. Casemaker caddisflies construct portable protective coverings by combining materials like leaves or sand with adhesive silk produced from glands under their lower lips. They carry these camouflaged cases around with them, which isn’t difficult as the cases have natural buoyancy.

Other critters observed in the stream included water striders, crayfish, fantail darters, and a bullfrog tadpole.  Black Branch received a stream health score of 7, indicating unacceptable ecological conditions. You can see the history of the health of this stream on the Black Branch site page.

Parasitic horsehair worm found at Black Branch.
Photo by Amy Ulland

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