Boshecapnia missiona, Baumann & Potter, 2007

Baumann, Richard W. & Potter, David S., 2007, What Is Bolshecapnia Sasquatchi Ricker? Plus A New Species Of Bolshecapnia From Montana (Plecoptera: Capniidae), Illiesia 3 (15), pp. 157-162 : 159-160

Boshecapnia missiona sp. n.

(Figs. 7-12, 15, 16)

Capnia (Bolshecapnia) sasquatchi Ricker, Nebeker and Gaufin 1967:243 . ♀ description, Montana.

Material examined. Holotype male, allotype female and 16 male and 7 female paratypes, Montana, Missoula Co., Grant Creek, Snow Bowl Road , north of Missoula , 15 March 1971, D.S. Potter . Holotype deposited at the California Academy of Sciences , San Francisco , California. Additional paratypes were examined from the following localities: UNITED STATES, Montana: Flathead Co., Alpha Creek , junction South Fork Flathead River , Hungry Horse Dam , 26 March 1966, P. Milam, 1 ♂ ( BYUC); Canyon Creek , South Fork Road , 25 March 1973, D.S. Potter and J.A. Stanford, 7 ♂, 4 ♀ ( BYUC, UMBS); Kootenai Creek , junction Middle Fork Flathead River , 26 March 1966, P. Milam, 8 ♂, 14 ♀ ( BYUC, UMBS); creek at MacDonald Hotel, Glacier National Park , 2 April 1966, P. Milam, 1 ♂ ( BYUC). Lake Co. , Six Mile Creek , between Swan Lake and Big Fork, 6 March 1966, P. Milam, 1 ♂ ( BYUC). Missoula Co. , Grant Creek, Snow Bowl Road, 31 December 1970, D.S. Potter and R.A. Haick, 3 larvae ( CSUC); 8 March 1970, D.S. Potter and R.A. Haick, 13 ♂, 3 ♀ ( BYUC); 23 March 1971, D.S. Potter, 15 ♂, 3 ♀ ( CSUC); 21 January 1972, R.A. Haick, 12 larvae ( BYUC); 5 March 1972, R.A. Haick, 24 ♂, 2 ♀ ( BYUC); 4 March 1973, R.A. Haick and D. McAuliffe, 5 ♂, 6 ♀ ( BYUC); 19 March 1973, R.A. Haick, 1 ♂, 9 ♀ ( CSUC); 20 March 1983, J. Bramlett, 1 ♂, 2 ♀ ( CSUC) .

Male. Body color dark brown to black, wings fumose, macropterous; length of forewings 6.5-7.0 mm; length of body 7.5-8.5 mm. Ninth sternum with large, round lobe or vesicle, covered by dense mat of short hairs, directed toward and overlapping apex. Tenth tergum bisected medially. Ninth tergum with large V-shaped notch along posterior margin. Epiproct long and thin, apex extending over posterior margin of tergum 8; dorsal plate extending to 1/3 length of epiproct, apical aspect deeply notched, forming sharply pointed, paired processes; basal lobe long and thin and directed upward in sinuate shape laterally, with median groove dorsally that terminates in pointed apex, tip bearing small membranous section that might be expandable; ventral surface well sclerotized, smooth and covered by few pit-like sensory structures (Figs. 7-12).

Female. Body and wing color similar to male, macropterous; length of forewings 9.0-10.0 mm; length of body 9.5- 10.5 mm. Subgenital plate broader than long, with narrow hairless area medially, posterior margin broadly rounded, bearing V-shaped median notch (Figs. 15-16).

Larva. Length 9.0-11.0 mm. Head, thorax and abdomen clothed in short, fine hairs. Femur with few long hairs on dorsal surface, ventral margin with two rows of short stout spines; tibia with sparse row of long, thin hairs along ventral margin. Mesosternal Yridge with wide reaching arms that extend nearly to bases of mesocoxal legs. Right mandible, as in Stewart and Stark (2002), with both terminal and basal teeth large and forked, fringe of short spines covering basal half of mandible; lacinia pointed, spines below terminal teeth short, longer hair-like spines on outer margin, extending along ½ of outer margin. Epiproct directed posteriorly on male larva.

Etymology. The species name is based on the fact that the type and most of the paratypes were collected in the Mission Mountains of Montana.

Diagnosis. Bolshecapnia missiona is most similar to B. sasquatchi , but it can be separated in the details of the epiproct and the posterior margin of the female subgenital plate. The epiproct is long and very thin apically in B. missiona with a pointed tip (Fig. 7), while in B. sasquatchi it is much shorter and ends in a bluntly rounded tip (Fig. 1), appearing foot shaped in lateral aspect (Fig. 4). Also, the dorsal plate covers nearly half of the epiproct in B. sasquatchi (Fig. 6) while in B. missiona it only reaches the basal third (Fig. 12). The female of B. sasquatchi has a subgenital plate with a straight, flat posterior margin (Fig. 13- 14), but the female of B. missiona exhibits a rounded subgenital plate that terminates in a median Vshaped notch (Figs. 15-16). The notch is always present but varies somewhat in size and shape. However, the female illustrated by Nebeker and Gaufin (1967) shows little or no notch. The larva is similar to the B. spenceri description in Stewart and Stark (2002) but shows slight differences in the shape of the mandible and lacinia.

Remarks. Bolshecapnia missiona is known mostly from first order and small second order streams at elevations from 750 to 1500 meters above sea level. Grant Creek is a freestone stream fed directly by snowmelt and cold seeps. High elevation reaches flow in small cascading pools and riffles over small angular cobble and gravel with an open southerly exposure. Twenty-meter-high steep slopes at streamside release cold seepage into thick moss over deep sand and gravel mixed with woody debris. Stream channels at lower elevation sites are mixed sand, gravel, and larger rounded cobble in long riffles forming a channel bordered by Alnus stands at streamside and open meadows on the floodplain. These lower reaches include an extensive hyporheic zone confirmed by nearby domestic water wells that penetrate 20-40 meters of saturated gravels as much as 200 meters laterally from the surface stream. Figs. 15-16 Bolshecapnia missiona female: Grant Creek, Montana. 15. subgenital plate, ventral, deep notch, 16. subgenital plate, ventral, shallow notch.