Megarcys watertoni
Creators: name: Stewart, Kenneth W.
name: Kondratieff, Boris C.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Plecoptera
Perlodidae
Megarcys
Megarcys watertoni

description: <i>Megarcys watertoni</i> (Ricker 1952) (Figs. 17, 23, 29, 35, 41, 47, 53, 65-68, 73, 75-77, 82, 87, Table 1) <b>Distribution.</b> Northern Rocky Mountains; Idaho, Montana, Alberta, British Columbia. <b>Material examined.</b> British Columbia: Kooteny National Park, 8-VII-1985, 2&amp;male;, 2&amp;female;, many exuviae. Montana: Carbon Co., Baring Falls, 28-VII-1989, B. Stark et al., 1&amp;female; larva; Rock Creek, 0.8 km below Glacier Lake Trailhead, 22-VII-1989, B. Stark, 1 brachypterous &amp;male; (to Ab9), 1 brachypterous &amp;male; (to Ab 5), 4&amp;female;, 1&amp;female; larva; Glacier Co., Baring Creek, Sunrift Gorge, Glacier National Park, 22-VII-1979, K. Stewart, R. Baumann, B. Stark, 4&amp;male; larvae, 5&amp;female; larvae; Iceberg Creek at Iceberg Lake, Glacier National Park, 29-VII-1969, R. Haick, 2 brachypterous &amp;male;, 1&amp;female;; 3-VII- 1972, J. Stanford, 3&amp;male; larvae, 1&amp;female; larva; 21-VII-1979, K. Stewart, R. Baumann, B. Stark, 1&amp;male; larva, 1&amp;female; larva; Roes Creek, Rising Sun Campground, Glacier National Park, 6-VII-1963, coll.?, 3&amp;male;, 3&amp;female;; Flathead Co., Bear Creek / jct. Middle Fork Flathead River, Hwy. 2, 7-VI-1996, R. Hansen, B. Ward (C. Nelson # 6347), 1&amp;male; larva, 1&amp;female; larva; Juliet Creek, Bob Marshall Wilderness, 19-VII-1981, J. Stanford, 1&amp;female;; Lion Creek, 14-VII-1985, K. Stewart, 4&amp;male; larvae, 4&amp;female; larvae; Logan Creek at Logan Pass, Glacier National Park, 11-VII- 1987, K. Stewart, 1&amp;male; larva; 2100 m, 10-X-1991, J. Giersch, 5 small larvae; Logan Creek /confluence McDonald Creek, Glacier National Park, 29-VI-1995, J. Giersch, 2&amp;male;, 1&amp;female;; Spotted Bear River at Pentagon, Bob Marshall Wilderness, 21-VII-1981, J. Stanford, 1&amp;male; larva. <b>Characters. Bear Creek,</b> <b>Montana, macropterous population:</b> Head capsule width &amp;male; 3.72mm, &amp;female; 4.32- 4.38mm; pronotal width &amp;male; 3.00mm, &amp;female; 3.90mm; body length &amp;male; 20.4, &amp;female; 24.3mm (Table 1). Color and pigmentation, lacinia, and dorsomesal band of erect white hairs similar to Iceberg Creek, Montana, population (described below) (Figs. 17, 23, 29, 35, 41, 47, 53). Wingpads of &amp;male; (Fig. 76) and &amp;female; macropterous. Gill number and arrangement typical of genus. Submental gill (Fig. 66) length &amp;male; 0.54-0.57mm, &amp;female; 0.66-0.72mm; anterior supracoxal gill (Fig. 67) length &amp;male; 0.36mm, &amp;female; (Fig. 68) 0.60-0.66mm (Table 1). Legs with typical setation of genus as described by Stewart &amp; Stark (2002). Y-arms of mesosternum typical of genus. Cercal segments &amp;male; 26 (Table 1), with setation typical of genus. Developing membranous windsock-like process of male epiproct evident in late instar individuals, and pointed posteroventrally in lateral view like the Iceberg Creek, Montana, population below (Figs. 73, 82). Developing female subgenital plate of 8 th sternum shallowly notched mesally like Glacier Creek population below (Fig. 87). <b>Iceberg Creek, Montana, male brachypterous</b> <b>(female macropterous) population:</b> Head capsule width &amp;male; 2.76-3.00mm, &amp;female; 3.48-3.84mm; pronotal width &amp;male; 2.58-2.64mm, &amp;female; 3.36mm; body length &amp;male; 16.08-17.28mm, &amp;female; 20.9-22.2mm (Table 1). Color and pigmentation (Figs, 17, 29, 35, 41, 47, 53), lacinia, (Fig. 23), and dorsomesal band of erect silky white hairs typical of genus. Wingpads &amp;male; (Fig. 75) brachypterous, &amp;female; (Fig. 29) macropterous. Gill number and arrangement (Fig. 65) typical of genus. Submental gill length &amp;male; 0.24-0.27mm, &amp;female; 0.36- 0.39mm; anterior supracoxal gill length &amp;male; 0.24- 0.27mm, &amp;female; 0.33-0.42mm (Table 1. Legs (Fig. 35) with typical setation of genus. Y-arms of mesosternum (Fig. 41) typical of genus. Cercal segments &amp;male; 26 (Table 1), with setation typical of genus. Developing membranous windsock-like process of male epiproct (Fig. 73) evident in late instar individuals, and pointed posteroventrally in lateral view (Fig. 82). Developing female subgenital plate of 8 th sternum (Fig. 87) shallowly notched mesally. <b>Comments.</b> The high elevation Iceberg Creek population was similar in color and pigmentation, and other generic characters, to the lower elevation Bear Creek population, except for male brachyptery and smaller body and gill sizes. Head capsule widths of males and females were on average 21.4% and 17.8%, respectively, smaller; pronotal widths of males and females were on average 13.0% and 13.8% smaller, and body lengths were on average 10.0% and 11.4% smaller (Table 1). Gill lengths were substantially smaller; submental gills of males and females were on average 54.1% and 45.7% shorter; anterior supracoxal gills of males and females were on average 29.2% and 40.5% shorter, respectively (Table 1).
description: Published as part of <i>Stewart, Kenneth W. &amp; Kondratieff, Boris C., 2012, Larvae Of The Nearctic Species Of The Stonefly Genus Megarcys Klapálek (Plecoptera: Perlodidae), pp. 16-36 in Illiesia 8 (3)</i> on pages 28-33, DOI: 10.5281/zenodo.4760667
description: {"references": ["Ricker, W. E. 1952. Systematic Studies in Plecoptera. Indiana University Publications Science Series, 18: 1 - 200.", "Stewart, K. W. &amp; B. P. Stark. 2002. Nymphs of North American stonefly genera (Plecoptera), 2 nd Ed. The Caddis Press, Columbus, Ohio. 510 pp."]}