Sweltsa townesi (Ricker)

Nye, Kelly C. & Stark, Bill P., 2010, A Scanning Electron Microscopy Study Of The Epiprocts Of Western North American Sweltsa (Plecoptera: Chloroperlidae), Illiesia 6 (18), pp. 248-255 : 252-255

Sweltsa townesi (Ricker)

Alloperla (Sweltsa) townesi Ricker, 1952:184 .

Holotype ♂ (Illinois Natural History Survey), California, [Tuolumne Co.], Dardanelle

Sweltsa townesi: Lee & Baumann, 2010:35 . Redescription with SEM

Material examined. CALIFORNIA: Alpine Co.: West Carson River , 12 July 1995, R. Bottorff, 1♂ ( BPS) . El Dorado Co.: Truckee River, Hwy 50, 13 July 1995, R. Bottorff, 2♂ ( BPS) . Nevada Co.: Sagehen Creek, Sagehen Biological Station , 19 June 1985, B. Stark, 16♂, 9♀ ( BPS) . Placer Co.: Truckee River, Hwy 89, Goose Meadow Campground , 22 June 2009, B. Stark, K. Nye, A. Harrison, 1♂, 1♀ ( BPS) . Plumas Co.: Graeagle Creek, Graeagle , 5 July 1979, B. Stark, K.W. Stewart, 1♂, 3♀ ( BPS) . Sierra Co.: Big Spring, Hwy 49, near Bassetts , 21 June 2009, B. Stark, K. Nye, A. Harrison, 1♂, 3♀ ( BPS) . Dark Canyon Creek, Lemon Canyon Road , 21 June 2009, B. Stark, K. Nye, A. Harrison, 2♂, 3♀ ( BPS) . Cold Creek , 1 mile south Cold Creek Campground, 5 July 1979, B. Stark, K.W. Stewart, 2♂ ( BPS) . NEVADA: Washoe Co.: small stream from Marletta Lake, Hwy 28, 24 June 2009, B. Stark, C. R. Nelson, K. Nye, A. Harrison, 9♂, 7♀ ( BPS) . Galena Creek, Galena Creek Park, 24 June 2009, B. Stark, C. R. Nelson, K. Nye, A. Harrison, 3♂, 16♀ ( BPS) .

Male epiproct. Total length ca. 500-530 µm, basal width ca. 125-150 µm, greatest width ca. 245-250 µm. Epiproct saggitate in dorsal aspect with thick tip slightly upturned and bearing narrow groove which extends from base to ca. 90-110 µm from apex ( Figs. 19-22 ). Dorsal surface bearing short, multifilament setae ( Fig. 23 ); ventral surface glabrous.

Dorsal process. Located on tergum 9. Total width ca. 160-180 µm, median notch shallow with truncate floor, notch width ca. 80-90 µm. Lobes of process triangular in outline ( Fig. 24 ).

Comments. The epiproct and dorsal process were illustrated by Ricker (1952). Surdick (1995) presented dorsal, dorsolateral and fully lateral outlines of this structure. More recently Lee & Baumann (2010) included five SEM images of the S. townesi epiproct in their redescription of that species. Surdick (1995) considered S. townesi and S. resima as sister species but data from the description and placement of S. salix in this group suggest S. townesi and S. salix are the more closely related pair ( Lee & Baumann 2010). Unfortunately, no support for either of these hypotheses is available from our limited study.

Figures

Figs. 19-24. Sweltsa townesi. 19. Epiproct, dorsal aspect. 20. Epiproct, dorsal aspect. 21. Epiproct apex, dorsal aspect. 22. Epiproct apex, anterior aspect. 23. Epiproct surface detail. 24. Process of tergum 9, anterior aspect. (Figs. 19, 21, 22, 23 = California, Nevada Co., Sagehen Creek; Figs. 20, 24 = Nevada, Washoe Co., stream from Marletta Lake).