Alloperla nanina Banks, 1911

Swannanoa Sallfly

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org:TaxonName:3622

(Figs. 13–22 & 39)

Alloperla nanina Banks, 1911:336 . Lectotype male (MCZ), North Fork Swannanoa River, Black Mountain, [Buncombe Co.], North Carolina (Syntype male examined, MCZ 681817)

Alloperla nanina: Needham & Claassen, 1925:126

Alloperla lodgei Frison 1935:340 . Holotype male (INHS), Fighting Creek, Gatlinburg, [Sevier Co.], Tennessee. Synonym Frison, 1942:34

Alloperla nanina: Frison 1935:341

Alloperla nanina: Frison 1942:344

Sweltsa nanina: Illies 1996:454

Alloperla nanina: Hitchcock 1974:182

Alloperla nanina: Nelson & Kondratieff 1980:803

Alloperla nanina: Stark et al. 1998:76

Alloperla nanina: Surdick 2004:18

Alloperla nanina: Willett & Stark 2009:123

Distribution. USA: GA, NC, TN, VA (DeWalt et al. 2018), SC (Kondratieff et al. 1995, Surdick 2004)

Material examined. USA, Georgia, Gilmer Co., Conasauga Creek, 16 km NW Elijay, Chattahoochee National Forest, 34.79495, -84.60325, 11 June 2016, S.A. Grubbs, 1 female (WKUC) ; Murray Co., tributary to Holly Creek, Chattahoochee National Forest, 34.81990, -84.59228, 11 June 2016, S.A. Grubbs, 2 females (WKUC) . North Carolina, Graham Co., seep into Panther Creek, Panther Creek Rd. off Rt. 28, 26 May 1993, 1 male, C.H. Nelson, B.C. Kondratieff & R.F. Kirchner (CHNC) ; Haywood Co., Flat Laurel Creek, ALS-63-14, 35.32434, -82.89611, 23 May 2014, A.L. Sheldon, 1 male (WKUC) ; Haywood Gap Stream, Trail 142, ALS-67-14, 35.32797, -82.94373, 24 May 2014, A.L. Sheldon, 1 male (WKUC) ; tributary to Flat Laurel Creek, TR 617, Pisgah National Forest, ALS-35-15, 35.32303, -82.89282, 22 July 2015, A.L. Sheldon, 1 female (WKUC) ; Macon Co., tributary to Cullasaja River, U.S. 64/ Rte. 28, 13 km SE Franklin, Nantahala National Forest, 35.08001, -83.25452, 12 May 2000, S.A. Grubbs, 1 male (WKUC) ; Wallace Branch, Cartoogechaye Creek, 4 km W Franklin, Nantahala National Forest, 35.18075, -83.43392, 13 May 2000, S.A. Grubbs, 2 males, 3 females (WKUC) ; Wine Spring Creek, nr. FS 711F, ALS-80-14, 35.17912, -83.59789, 28 May 2014, A.L. Sheldon, 1 male, 1 female (WKUC) ; Macon Co., Robin Branch, Wayah Bald, 13 June 1996, B.P. Stark, 1 male (BPSC) ; Robin Branch, Wayah Bald, 9 June 1998, J. Wise, J. Carter, J. Beaty & D. Beaty, 1 male (BPSC) ; Watauga /Caldwell Co. line, Hwy 221, 25 May 1994, B.P. Stark, S.W. Szczytko & J. Sandberg, 1 male (BPSC) ; Swain Co., small sinking stream, US 441 at parking lot, near Newfound Gap, Great Smoky Mountains National Park, 35.60775, -83.43703, 1 June 2015, S.A. Grubbs, 1 male (WKUC) ; Yancey Co., Hemphill Creek, FS 472, ALS-50-14, 35.71024, -82.25057, 20 May 2014, A.L. Sheldon, 1 male (WKUC) . South Carolina, Pickens Co., Wildcat Creek, 5.5 mi NW of Clemson, 24 April 1968, P.H. Carlson, 1 male, 1 female (BPSC); Wildcat Creek, 9 km NW Clemson, 6 May 1976, P.H. Carlson, 1 female (BPSC) ; Wildcat Creek, 14 May 1976, P.H. Carlson, 1 female (BPSC) ; Wildcat Creek, 9 km NW Clemson, 5-6 May 1979, T.R. White, 1 male, 2 females (BPSC) . Tennessee, Polk Co., Rock Creek, Parksville Lake Campground, Rt 30, 0.5 mi N Jct 30/64, Cherokee National Forest, 13 May 1985, C.H. Nelson, 5 males, 3 females (CHNC) . Virginia, Smyth Co., Saint Claire Bottom, Route 600, 19 May 1990, B.C. Kondratieff & R.F. Kirchner, 3 males (CSUC) ; Grindstone Campground, Mt. Rogers National Recreational Area, 24 May 1994, B.P. Stark, S.W. Szczytko & J. Sandberg, 1 male (BPSC) .

Amended description – Male. Tergum 10 divided mesally by epiproct and reduced cowl into two hemitergal lobes; lobes bearing dense matting of long setae (Figs. 13–15). Epiproct length (L) 125 µm, maximum width (MW) 40 µm, L:MW ratio = 3.2. In dorsal view the epiproct is widest in basal ⅓, tapering anteriorly and distally. The entire dorsal surface is bare (Figs. 14–17). The apical notch is narrowly triangular and extends anteriorly and ventrally as a groove between paired, serrated apical margins (Figs. 15–18); 10 distinct teeth are present (Figs. 17, 21–22); the serrated apex is arcuate ventrally (Figs. 19–22). The epiproct stem is secondarily reduced and nearly absent; the serrated portion comprises the entire lateral profile (Figs. 19–22). Dense hair matting is also absent laterally; a sparse group of long hairs are present in medial ⅓ (Figs. 20–22).

The adults of A. nanina are unusual amongst eastern Nearctic Alloperla species in that the pronotum has a charcoal gray pigmentation within the medial 75% of the segment (the entire margin is pale yellow in color), the mesonotal and metanotal scutellar margins are darkly pigmented, and the abdomen has darkened medial and lateral stripes (Surdick 2004, Grubbs & Singai 2018, their fig. 15).

Comments. The taxonomic histories of A. banksi Frison, 1942 and A. nanina are intertwined. As was customary at the time, the original Banks (1911) description lacked illustrations. He indicated that individuals were small, the pronotum was darkly pigmented, plus this species was then only known from the type locality in western North Carolina. Although Needham & Claassen (1925) attempted to provide the first illustrations of the male of A. nanina (their plate 20, fig. 3), this unintentionally represented an undescribed species. They noted variability at the tip of the epiproct, namely as “…sharply-pointed and smooth…” or “…bilobed…” and added that this did not justify differentiation into separate species. Several additional locality records were also added from New York and Nova Scotia. Soon thereafter, Frison (1935) mistakenly described A. lodgei as new from Gatlinburg, Tennessee, providing several illustrations, especially his plates XIII (his fig. 25) and XIV (his fig. 36) that now are easily recognized as A. nanina . Frison (1942) recognized the Needham & Claassen (1925) mistake, described A. banksi from New York, and synonymized A. lodgei under A. nanina . Surdick (2004) has likewise provided a brief taxonomic history. The New York listing in DeWalt et al. (2018) now pertains to A. banksi . Alloperla nanina appears to be a species endemic mainly to the southern Appalachian Highlands region (Fig. 39).