Zealeuctra arnoldi Ricker & Ross

Grubbs, Scott A., Kondratieff, Boris C., Stark, Bill P. & DeWalt, R. Edward, 2013, A review of the Nearctic genus Zealeuctra Ricker (Plecoptera, Leuctridae), with the description of a new species from the Cumberland Plateau region of eastern North America, ZooKeys 344, pp. 17-47 : 20-21

Zealeuctra arnoldi Ricker & Ross Figs 1, 12

Zealeuctra arnoldi Ricker & Ross, 1969: 1114. Holotype ♂ (INHS), Sorrell Creek, 1 mi S of Hancock, Comal Co., Texas

Description.

Male - epiproct. Base short and robust, narrowing slightly to a short, recurved, subtriangular spine (Figs 1 B–C). A short, slightly concave projection extends anteriorly from the base to approximately the same plane as the spine. Base with bulbous posterior swelling, spine with small accessory posterior cusp that is low and nub-like.

Female - 7th sternum. Seventh sternum with a large, subquadrate lobe nested in a distinct, central notch. The notch is bordered laterally by large, convex “shoulders” (Fig. 1D).

Male - abdominal tergal cleft. Simple in outline. Anterior portion wide and broadly U-shaped, with a nearly straight terminal margin (Fig. 1A). Posterior portion narrowing slightly with no medial projections and only scarcely visible crenulations along inner margins.

Material examined.

USA, Texas: Bandera Co., Myrtle Creek, FR 2828 S of Camp Verde, 29.8242, -99.1347, 3.IV.2004, B.C. Kondratieff and R.E. Zuellig, 4♂, 13♀ (CSUC); Little Creek, Farm Rd. 470 E of Utopia, 29.6514, -99.4767, 3.IV.2004, B.C. Kondratieff and R.E. Zuellig, ♂ (CSUC); Hays Co., Barton Creek, Hwy 12, N of Dripping Springs, 30.2380, -98.0665, 14.III.1993, B.C. Kondratieff and R.W. Baumann, 5♂, 21♀ (BYUC, CSUC); Paradise Hills, 25 January 1988, B.P. Stark, 2♂, 2♀ (BPSC); Travis Co., tributary of Barton Creek, near bowery of Hill Country Preserve in Bee Caves, downstream of Hwy 71, 20.III.1997, C.R. Nelson, 18♂, 13♀ (BYUC); Uvalde Co., Cherry Creek, Farm Rd. 1050 W of Utopia, 29.6061, -99.6925, 3.IV.2004, B.C. Kondratieff and R.E. Zuellig, 54♂, 38♀ (CSUC); Bear Creek, Farm Rd, 1050 W of Utopia, 29.5989, -99.5664, 3.IV.2004, B.C. Kondratieff and R.E. Zuellig, 72♂, 68♀ (CSUC).

Distribution.

USA: TX ( DeWalt et al. 2012)

Remarks.

This species is somewhat superficially similar to Zealeuctra fraxina . Males are easily identified by the combination of the simple, U-shaped cleft and the presence of the anterior, concave cusp present at the base of the short, compact epiproct spine. The depiction of the posterior cusp as pointed and acute in Ricker and Ross (1969, their fig. 2) is not accurate and typically not visible. The cusp tends to be low and nub-like. This species is known mainly from the Edwards Plateau of west-central Texas (Fig. 12).