Saturday, June 1, 2013
Rapidan River, Pt. I.: everything "but" the Isoperla orata
I have no doubt that I found Isoperla orata -- Perlodid stonefly -- this morning at the Rapidan River. Actually, I saw 4-5 of the nymphs. But in this entry let me post photos of everything else that I found: I want to make the full case for the I. orata ID in a separate entry using Beaty and Frison (the entomologist who first described this as a new species).
1. Limnephilidae (Northern case-makers), Pycnopsyche scabripennisis (TV, 2.5). I was expecting to see them, and I found three. I was hoping for more elaborate cases, but we take what we can get. The two in the photos below both constructed the "hot dog" case -- two long twigs on the sides, filled in with bits of wood and bark. (The I. orata nymph on the back of the case is 8 mm which will give you some sense of the size of the case.)
2. A very nice, very large Epeorus vitreus flatheaded mayfly. Here as elsewhere they were all over the bottoms of rocks. Like the orange color.
3. Spiny crawler mayfly, E. dorothea. Still a lot of them at the Rapidan river in clumps of twigs, roots and leaves.
4. Perlodid stoneflies - Isoperla holochlora. The bug of the day without any doubt. They were simply all over the place.
5. And a common netspinner caddisfly larva, Ceratopsyche slossonae, tolerance value, 0.0. This is the one that has the single pale dot in the middle of its head -- well, face.
Now, full attention tomorrow (Part II.) on our new addition to the EPT list, Isoperla orata.