Sweltsa mediana (Banks)

(Figs. 11-15)

Alloperla mediana Banks, 1911:336 .

Holotype ♀ (Museum of Comparative Zoology), North Carolina, Black Mountain, North Fork of Swannanoa River

Material examined. NORTH CAROLINA: Haywood Co.: Great Smoky Mountains National Park, Cataloochee River, 4 May 1985, K.W. Stewart, B.C. Kondratieff, R . F. Kirchner, 7♂, 4♀, 7 larvae (KWS) . TENNESSEE: Sevier Co.: Great Smoky Mountains National Park, 2 mi below Newfound Gap Summit, 18 May 1993, B. Stark, B.C. Kondratieff, R . F. Kirchner, 1 pharate larva. Great Smoky Mountains National Park, Greenbriar Cove, 3 mi above Ranger Station, 17 May 1983, B. Stark, B.C. Kondratieff, R . F. Kirchner, 3♂, 3♀, 1 larva (BPS) .

Mature larva. Body length 7.0-8.0 mm. General color pale brown without distinctive pigment pattern except underlying adult pattern in pharate individuals. Pronotum bearing ca. 14 anterolateral setae and ca. 16 posterolateral setae near margin; posterolateral setal row extends to median suture (Fig. 11).Mesonotum bearing prominent setae scattered along outer margin from base to apex (Fig. 12), and a few inner marginal setae near notch. Metanotum with several outer marginal setae and a large grouping of intercalary setae on wingpad surface; apex of wingpads with interspersed long and short setae. Fore femora with a few fringe setae, tibiae sparsely fringed on outer surface (Fig. 13). Thick setae present on dorsal and ventral margins and a few scattered on femoral surface; tibiae bearing long thin setae and a row of short thick setae along outer margin. Posterior abdominal fringe on tergum 8 with a mixture of thin and thick setae between innermost long setae (Fig. 14); intercalary setae clustered in lateral group of ca. 7. Cerci with ca.15 segments; long dorsal setae in segmental whorls about as long as 1.5 segments (Fig. 15).

Comments. This southern Appalachian species is found in the upper Tennessee River drainage southward in the mountainous regions of North Carolina, South Carolina, Tennessee and Virginia (Surdick 2004) and earlier records from Alabama were recently assigned to S. hoffmani by Grubbs (2010). Generally S. mediana occurs in larger streams than S. lateralis, but they are known to be sympatric at numerous sites. Mature larvae of S. mediana are the only southern Appalachian Sweltsa species with a long tibial fine setal fringe (Fig. 14). See additional comments above for S. hoffmani .