Leuctra variabilis Hanson 1941

Variable Needlefly

http://lsid.speciesfile.org/urn:lsid: Plecoptera .specie sfile.org:TaxonName:460700

(Figs. 48‒52)

Leuctra variabilis Hanson 1941:62 . Holotype ♂ (USNM), Paradise Trail, Sunderland, Massachusetts Leuctra variabilis: Illies 1966:111

Male. The 7th abdominal dorsal process shown herein from eastern Tennessee is symmetricallytrapezoidal with no appearance of lateral lobes (Fig. 48). The specimens examined from eastern Kentucky have small, laterally-directed spurs, yet still lack the appearance of lateral lobes. The specilla are broad basally, tapering slightly and not recurved; specilla mostly smooth in appearance, bearing shallow pits along the distal outer margin and very few raised tubercles (Figs. 49‒52). The subanal lobes are narrow throughout length, gently recurved anteriorly, and ca. 90% the length of the inner lobes (Figs. 49, 51‒52).

Material examined. USA, Kentucky, Harlan Co., Watts Creek, Blanton Forest State Nature Preserve, 36.8619, -83.3753, 9 September‒4 November 2009, M.A. Floyd, 4♂ (DCTC) . North Carolina, Mitchell Co., tributary to Holder Creek, FS 130, 36.1018, - 82.1266, 23 October 2014, A.L. Sheldon, 1♂, 1♀ (WKU) . Tennessee, Carter Co., Twin Springs, 26 km N Spruce Pine (NC) , Cherokee National Forest, 36.1213, -82.0865, 29 November 2002, S.A. Grubbs, 3♂ (WKU) .

Distribution. USA: MA, MD, ME, NH, NJ, NY, PA, VA, VT (DeWalt et al. 2015), NC, TN (new state records).

Remarks. The abdominal dorsal process of L. variabilis is similar only to L. usdi . Hanson (1941, fig. 7) depicted three forms of the dorsal process, namely with the absence or presence of small lateral lobes that appear superficially-similar to L. usdi (Fig. 43). These two species can more readily be separated by characteristics of the specilla. The distal outer margin of the specilla of L. usdi bears numerous raised tubercles (Figs. 45, 47) whereas on L. variabilis the tubercles are lacking along the distal outer margin and at the tips (Figs. 49‒52). The shallow pits present along the outer margin on L. variabilis are lacking on L. usdi . Additionally, L. usdi is a spring-emergent species whereas L. variabilis emerges during late summer and autumn.