Isoperla powhatan Szczytko and Kondratieff, 2015

Beaty, Steven R., Holland, Victor B. & Lenat, David R., 2017, Isoperla Arcana And Isoperla Borisi (Plecoptera: Perlodidae), Two New Stonefly Species From North Carolina, U. S. A. With Notes On The Distribution Of Isoperla Powhatan, Illiesia 13 (14), pp. 140-166 : 164

Isoperla powhatan Szczytko and Kondratieff, 2015

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org: TaxonName:468708

Material. USA – North Carolina, Montgomery

Co., Barnes Creek, Ophir Rd, 35.43861, -79.99888, 7/ V /2014, D. R. Lenat, 4 larvae, 3♂ (reared) and exuvia; 2/ V /2015, S. R. Beaty, D. R. Lenat, 3♂ (reared) and exuvia.

Remarks. Males of I. powhatan , recently described by Szczytko & Kondratieff, (2015a), were successfully reared from larvae collected from Barnes Creek, a 4 th order tributary of the Uwharrie River. Previous to this reporting, I. powhatan was recorded only from Pennsylvania and Virginia. Szczytko & Kondratieff (2015a) considered the distribution of this species to be wider than they initially reported but material from adjacent states was unavailable for study.

This first North Carolina record of I. powhatan resulted from attempts to rear and associate the larvae of I. zuelligi Szczytko & Kondratieff, 2015 , another recently described North Carolina species. Whereas I. zuelligi was not reared from collected larvae, adult I. zuelligi males and females with eggs were collected concurrently from nearby low riparian vegetation.

Isoperla powhatan males exhibit a unique and somewhat box-shaped aedeagus with a long, wide median band of sharp, stout golden-brown spinulae located between a pair of posteromesal lobes (see 42.7 and 42.8 in Szczytko and Kondratieff 2015a). In conjunction with the broadly rounded paraprocts and the unique head pattern, the identity of this species is unmistakable. Associated larvae and exuvia from reared specimens closely resemble a dark-form habitus of I. holochlora larvae. However, stable morphological characters for separating larvae of I. powhatan and I. holochlora remain elusive.

Barnes Creek is the type locality for I. zuelligi . The stream lies in the Carolina Slate Belt Level IV ecoregion in the midst of the Uwharrie Mountains, a relict mountain chain located in the North Carolina piedmont. Much of the Uwharries are managed as National Forest and thus the greatest impacts to local waterbodies are from timber harvest. Similar to most slate belt streams, Barnes Creek experiences reduced summer flows and a heavy silt load.