Leuctra variabilis Hanson 1941

Grubbs, Scott A., 2015, Leuctra Schusteri, A New Stonefly Species (Plecoptera: Leuctridae) Of The L. Tenuis (Pictet) Group From The Southeastern Usa, Illiesia 11 (12), pp. 147-166 : 165

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.

Figures

Figs. 48–52. Leuctra variabilis, Tennessee, Twin Springs. 48, 7th abdominal process, dorsal view, 350X; 49, paraprocts, caudal view, 350X; 50, paraprocts, caudal view, 1500X; 51, paraprocts, lateral view, 350X; 52, L. variabilis, paraprocts, lateral view, 1500X. sp = specillum, sa = subanal lobe.

Figs. 43–47. Leuctra usdi, Tennessee, spring into Pinewood Branch. 43, 7th abdominal process, dorsal view, 350X; 44, paraprocts, caudal view, 500X; 45, paraprocts, caudal view, 2000X; 46, paraprocts, lateral view, 350X; 47, L. usdi, paraprocts, lateral view, 1500X. sp = specillum, sa = subanal lobe, ll = lateral lobe, ml = medial lobe.