Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
This one was surprisingly straightforward to identify. The lack of a sclerite at the base of the lateral hump narrows the field quite a bit, and the other options followed fairly obvious characteristics to Clostoeca, which only has one species, Clostoeca disjuncta.
Millcreek on May 9, 2015May 9th, 2015, 7:05 am EDT
These were determined to genus using Merritt, Cummins and Berg (2008) as well as Wiggin's "Larvae of the North American Caddisfly Genera" (1996). They were identified to species using Don Burdick's illustrations of Trichoptera. Mature male pupae were used to make the species determination.
The mature larvae were 3 - 3.5 long with the cases measuring about 4 mm in length. The pupal cases were about 4 - 4.5 mm long. The larvae were found on Cladophora algae in a fairly fast flow. The pupal cases were in aggregations on the rocks.
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