Ostrocerca albidipennis ( Walker, 1852 )

Grubbs, Scott A. & Baumann, Richard W., 2023, The Nemourinae (Insecta, Nemouridae) of the eastern Nearctic, Zootaxa 5306 (1), pp. 1-53 : 10

2. Ostrocerca albidipennis ( Walker, 1852)

Whitetailed Forestfly

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org:TaxonName:6147

( Figs. 2 , 19–24 )

Nemoura albidipennis Walker, 1852:191 . Holotype male ( British Museum of Natural History ), Nova Scotia, Canada

Nemoura serrata: Claassen, 1923:289 . Syn. Ricker, 1952:39

Nemoura serrata: Needham & Claassen, 1925:218

Nemoura albidipennis: Claassen, 1940:50

Nemoura serrata: Claassen, 1940:63

Nemoura (Ostrocerca) albidipennis: Ricker, 1952:39

Nemoura (Ostrocerca) albidipennis: Ricker, 1965:489

Ostrocerca albidipennis: Illies, 1966:217

Nemoura (Ostrocerca) albidipennis: Harper & Hynes, 1971:1136

Ostrocerca albidipennis: Zwick, 1973:343

Nemoura (Ostrocerca) albidipennis: Hitchcock, 1974:96

Ostrocerca albidipennis: Young et al., 1989:259

Ostrocerca albidipennis: Stark, 2017:212

Distribution. Canada: NS, ON, PQ. USA: CT, MA, MD, ME, MI, NH, NY, OH, PA, VA, WV ( DeWalt et al. 2022)

Male. Macropterous. Body length 4.1–5.4 mm, forewing length 5.0– 5.6 mm (n = 11). Gills absent. Cerci enlarged and elongated, sclerotized, medially arcuate, and terminating to an apical point ( Figs. 19–20 ). Paraprocts divided into a membranous outer lobe and a sclerotized inner lobe; inner lobe is long, bearing a laterally-directed medial hook and a hook-like projection apically ( Fig. 22 ; Young et al. 1989, their figs. 3‒4). Epiproct elongate and complex; dorsal sclerite recurved dorsally, with membranous lateral arms that extended posteriorly ( Figs. 20–22 ); the ventral sclerite is butterfly-shaped ventrally and broadly T-shaped sclerite dorsally ( Figs. 20–21 ), the latter overlapped by the dorsal sclerites lateral arms.

Female. Macropterous. Body length 4.1–6.7 mm, forewing length 5.9–7.0 mm (n = 26). Gills absent. Cerci enlarged but unmodified ( Fig. 23 ). The 8 th sternum is moderately enlarged as a subgenital plate, extending only partially over the 9 th sternum and distally concave; medial region is unsclerotized ( Figs. 23–24 ). The 7 th sternum is modified slightly as a small nipple-shaped process that extends barely to the anterior margin of the 8 th sternum ( Figs. 23–24 ).

Larva. Described by Harper & Hynes (1971). An additional partial illustration of the male abdominal tergum was provided in Stark (2017).

Comments. Ostrocerca albidipennis is distributed from Nova Scotia south through the Appalachians to Virginia and West Virginia ( DeWalt et al. 2022). In addition, this is the only species of Ostrocerca known westward across the northern Great Lakes region ( Grubbs et al. 2012).

Figures

FIGURES 1‒8. Forewing images. 1, Nemoura arctica, USA, Michigan, Silver Creek; 2, Ostrocerca albidipennis, USA, West Virginia, Middle Fork Indian Run; 3, Paranemoura perfecta, USA, West Virginia, headwaters Sugar Creek; 4, Podmosta macdunnoughi, USA, New York, Grampus Brook, dark line at tips of arrows represent the termini of veins A1 and A2; 5, Prostoia completa, USA, Kentucky, Middle Fork Drakes Creek; 6, Shipsa rotunda, USA, Michigan, Montreal River; 7, Soyedina calcarea, USA, Kentucky, tributary Green River; 8, Zapada katahdin, Canada, Labrador, tributary Leg Lake.

FIGURES 19‒24. Ostrocerca albidipennis. 19, male abdominal terminalia, dorsal view; 20, USA, New York, Oquaga Creek, male abdominal terminalia, dorsal view; 21, USA, New York, Oquaga Creek, epiproct, dorsal view; 22, USA, New York, Oquaga Creek, epiproct, ventral view; 23, female abdominal terminalia, ventral view; 24,USA,Ohio, tributary Pike Run, female abdominal terminalia, ventral view. c = cercus, ds = dorsal sclerite, ipl = outer paraproct lobe, la = lateral arm, sgp = subgenital plate, vs = ventral sclerite.