Bryelmis idahoensis Barr, 2011

Barr, Cheryl B., 2011, BryelmisBarr (Coleoptera: Elmidae: Elminae), a New Genus of Riffle Beetle with Three New Species from the Pacific Northwest, U. S. A., The Coleopterists Bulletin 65 (3), pp. 197-212 : 197-212

Bryelmis idahoensis Barr , new species ( Figs. 3–5 , 10 , 11 )

Description. Length 2.00– 2.34 mm; width 1.04–1.18 mm. Body color dark brown to black; rugose and sculptured with prominent carinae, sulci, striae, and punctures. Antenna: Testaceous, often darker at tip. Head: Dark brown to black. Eyes strongly protuberant. Frons finely rugose with moderately coarse punctures and long, pale setae; epicranial sutures prominent. Clypeus with fine punctures, evenly spaced more than 2X their diameters apart, integument between punctures smooth; setae moderately long, sparse except at lateral margins. Labrum with evenly spaced fine punctures bearing sparse, moderately long setae; apico-lateral margins with dense clusters of setae. Pronotum: Dark brown to black, shiny. Distinctly wider than long, widest about 1/3 distance from base or occasionally at base; length 0.60–0.70 mm, width at widest point 0.84–0.96 mm. Basalolateral angles right-angled to slightly obtuse, occasionally slightly acute. Disc smooth, with small, sparse punctures accompanied by fine setae distributed mostly along midline and near lateral margins; longitudinal, central elevation bearing a narrow, median, longitudi- nal carina extending from near apical margin to basal margin. Sublateral carinae prominent, narrow or broad but not sharply carinate; each bordered medially by a rounded basal and an elongate apical fossa, both moderately deep. Elytron: Convex; shiny with short, sparse setae; dark brown to black, occasionally red brown, often with a slight metallic sheen. Length 1.50–1.78 mm, width 0.50–0.58 mm. Disk usually flattened at basal 1/3 with broad, shallow depression present laterad of suture, distinctly humped at middle, angled downward at apical 1/2; sometimes not flattened at base and without depression, and more evenly rounded from base to apex. Two distinct sublateral carinae at intervals 7 and 8; the more medial stria ending abruptly at about 1/5 the distance from the elytral apex; the more lateral stria slightly shorter. Deep longitudinal sulcus bordering lateral margin, with deeper fovea adjacent to metasternum. Nine, often deeply-impressed striae with moderately deep punctures separated by 1X their diameters. Leg: Shiny, red brown except for distal 1/4–1/3 of femur which is dark brown; visible portion of femur dark in dorsal habitus view. Femur with closely spaced, minute punctures and sparse setae. Venter: Shiny, red brown to dark brown medially, prosternum darkest; dense silver to golden plastron present laterally. Apex of prosternum broadly rounded. Mesosternal disc deeply concave between mesocoxae. Metasternal disc convex. Male genitalia: In dorsal view ( Fig. 5 ), parameres with outer margins more or less parallel, tips narrowly rounded. Penis slightly longer than parameres, widest near middle then abruptly narrowed to a blunt tip which is about as wide as that of a paramere.

Variation. There is notable individual variation in this species, even within a single population. All specimens examined were strongly sculptured and striate, but varied in the degree of pronotal and elytral convexity, the presence or absence of basal elytral depressions, the presence or absence of metathoracic wings, and the width of the pronotum at the apical margin behind the head ( Figs. 3, 4 ). Figure 4 illustrates an unusually stocky and sculptured specimen with deep elytral striae. Body size and color, ranging from occasionally red brown to more common dark brown and black, are other variables. Females (n = 5) were slightly longer than males (n = 5) in a comparison of the length measurements of the longest and shortest specimens, with the longest specimen a female and the shortest a male.

Comparative and Diagnostic Comments. Bryelmis idahoensis ( Figs. 3, 4 ) is black or dark brown with a body that is generally rugose and sculptured with prominent carinae, sulci, striae, and punctures. The median pronotal carina is produced and ridge-like, the pronotal disc is relatively smooth with few punctures and setae, and the lateral elytral sulcus is deep and trench-like. Its overall appearance is broad, stocky, and “tanklike”. Bryelmis rivularis ( Fig. 8 ) and B. siskiyou ( Fig. 9 ) are much less rugose with elytra not as deeply striate, shallow lateral elytral sulci, less prominent median longitudinal pronotal carinae, and more punctation and setation on the pronotal discs. The male genitalia of B. idahoensis ( Fig. 5 ) is somewhat similar to that of B. siskiyou ( Fig. 6 ), but differs from that of B. rivularis ( Fig. 7 ) which has the paramere tips angled outward.

Material Examined. 458 specimens. HOLO- TYPE ♂ in EMEC, labeled “ IDAHO: Clearwater Co., Clearwater NF, Fern Creek at FS Rd. 700 N of Isabella Landing, 14-VII-2007, C. B. Barr // trib. Isabella Creek, 46°51.703′ N, 115°37.379′ W, elevation 1980 ft. // HOLOTYPE Bryelmis idahoensis Barr ” [red label]. Two hundred two paratypes (P) [yellow labels] and 255 non-paratypes ( NP) were examined from the following localities: Same data as holotype (4 P, BNHM; 4 P, CASC; 2 P, CNCI; 22 P, 3 NP, EMEC; 4 P, USNM). IDAHO: Clearwater Co.: Clearwater NF, Deadhorse Creek along FS Rd. 246 nr. Sheep Mtn. Work Ctr., 19-VIII- 1999, M.Wolfe // trib. N. Fk. Clearwater R. ∼ 13 mi. NE Headquarters, T39N R07E S08 NW SE NE, elev. 3480 ft. (2 P, CIDA; 2 P, 2 NP, EMEC; 2 P, WFBM); Clearwater NF, Deadhorse Creek at FS Rd. 246, 14-VII-2007, C. B. Barr // trib. N. Fk. Clearwater River, SE Sheep Mtn. Saddle, elev. 3517 ft., 46°44.499′ N, 115°35.983′ W (6 P, EMEC); data same, except W. D. Shepard (9 NP, WDSC); Clearwater NF, Fern Creek at FS Rd. 700 ∼ 20 mi. NE Headquarters, 31-VIII-1999, M.Wolfe // tributary Isabella Cr., N. Fk.Clearwater R., T41N R07E S30 SW SE SE, elev. 2000 ft. (3 P, 1 NP, CIDA; 2 P, WFBM); Fern Cr. -Isabella Cr., -115.6220, 46.8618, 28 JUL 2003, D.L. Gustafson, W1889 (8 P, MTEC); 1 mi N Isabella Landing, 14 VII 07, 1980′, Fern Creek // William D. Shepard, leg. (6 P, 58 NP, WDSC); Gorman Cr. mid Br., 115.0780, 46.6722, 03 JUL 2002, 1158 m, D.L. Gustafson, W1660 (2 P, MTEC); Isabella Creek, IX-15/ X-22-2005, pitfall trap in moist old growth cedar forest, F.W. Merickel (2 P, WFBM); Clearwater NF, tributary Isabella Cr. at FS Rd. 700 0.9 mi. N Isabella Landing, 14-VII-2007, C. B. Barr // 46°51.593′ N, 115°37.379′ W, elevation 1980 ft. (16 P, 1 NP, EMEC); 0.9 mi N Isabella Landing, 14 VII 07, 1980′, unnamed stream // William D. Shepard, leg. (3 P, 22 NP, WDSC); Clearwater Natl. For., Laundry Cr. at FS Rd. 737, 28-VII-1997, coll. A. Stonesifer // down ridge from FS Rd. 737 mi. marker 6, elevation 3840 ft., 46°46′12″N, 115°03′42″W (1 NP, EMEC); Clearwater NF, Little Washington Cr. at FS Rd. 246 ∼ 15 mi. NE Headquarters, 30-VIII- 1999, M. Wolfe // trib. N. Fk. Clearwater R., T40N R07E S34 SE NE NW, elev. 3620 ft. (1 P, WFBM); Clearwater NF, Little Washington Creek at FS Rd. 246, 14-VII-2007, C. B. Barr // trib. N. Fk. Clearwater R., elev. 3653 ft., 46°46.222′ N, 115°33.964′ W (2 P, CNCI; 19 P, 4 NP, EMEC; 2 P, LSAM; 2 P, OMNH); 4.7 mi NE FS 680 X FS 246, 14 VII 07, Little Washington Cr // William D. Shepard, leg. (5 P, 122 NP, WDSC); Clearwater NF, trib. Little Washington Creek at FS Rd. 246, 14-VII-2007, C. B. Barr // trib. N. Fk. Clearwater R., elev. 3637 ft., 46°45.787′ N, 115°34.365′ W (3 P, EMEC); Orofino Cr. -Thompson Gulch, 02 JUL 2002, 1038 m, D.L. Gustafson, W1653 (1 P, MTEC); Orogrande Cr. -Mill Cr., -115.5067, 46.6127, 27 JUL 2003, 0763 m, D.L. Gustafson, W1885 (1 P, MTEC); Clearwater NF, Pete Ott Creek at FS Rd. 250 N of Kelly Forks RS, 21- VII-1998, T. Apel // trib. N. Fk. Clearwater R.. 25 mi. above confl., T39N R10E S6 NW NE NE, elev. 1036m (1 P, EMEC). Idaho Co.: Ashpile Creek. 25 mi. upstream from Hwy. 12, T 36N. R11E.,S14 SE.,NW.SE, 890m, 1998SLEW A0006, VI-29-1998, M. Rayton coll. // larvae in ETOH collection, specimen received from EcoAnalysts, Inc., J.J. Pfeiffer (6 P, WFBM); Ashpile Cr. -low, -115.0636, 46.4602, 29 JUN 1998, 976 m, M. Rayton colr. (2 P, MTEC); Nez Perce NF, Ballinger Cr. ca. 22 mi. E of Lowell, 11-VIII-1998, M. Rayton // tributary Selway R. 400m above bridge, T32N R10E S25 NE NE SW, elev. 585m (1 P, EMEC); Clearwater NF, Bridge Creek at US Hwy. 12 ca. 3 rd. mi. W Lowell, 14-VII-2007, C. B. Barr // trib. Mid. Fk. Clearwater R., elevation 1445 ft., 46°08.467′ N, 115°39.432′ W (1 P, EMEC); Rt 12, Canyon Creek, ca 6.4 mi. NE of Lowell, 26 Sept 1991, R. S. Zack collector (1 P, WSUC); Nez Perce NF, Fall Creek at Hwy. 14 1.8 rd. mi. E Golden, 12-VII-2007, C. B. Barr // trib. S. Fk. Clearwater R., elev. 3555 ft., 45°48.672′ N, 115°38.978′ W (1 NP, EMEC); Nez Perce NF, lower Huddleson Creek ca. 17 mi. ESE Grangeville, 30-VII-1999, M. Rayton // trib. S. Fk. Clearwater R. just above confluence, T28N R05E S35 NW SW NW, elev. 2900 ft. (1 P, EMEC); Nez Perce NF, trib. Meadow Creek at FS Rd. 443 nr. Selway Falls Cgd., 15-VII- 2007, C. B. Barr // trib. Selway River, 46°02.521′ N, 115°17.738′ W, elevation 1683 ft. (9 P, EMEC); S of FS 223 X 443, 15 VII 07, 1683’, unnamed stream // William D. Shepard, leg. (2 P, 6 NP, WDSC); Rainy Day Cr. -mouth, -115.6940, 45.8030, 01 JUL 2002, 1041 m, D.L. Gustafson, W1651 (3 P, MTEC); Nez Perce NF, trib. Selway R. at FS Rd. 223 ca.12.5 rd. mi. SE Lowell, 15-VII- 2007, C. B. Barr // 46°04.563′ N, 115°24.694′ W, elevation 1695 ft. (3 P, EMEC); Sheep Creek at US Hwy. 95 nr. Sheep Creek Rest Area, 6.1 rd. mi. S Riggins, 11-VII-2007, C. B. Barr // trib. Little Salmon R., elevation 2157 ft., 45°20.558′ N, 116°21.000′ W (7 P, EMEC); data same, except W. D. Shepard (4 NP, WDSC); Nez Perce NF, Simmons Cr. 11 mi. ENE Elk City, 24-IX-1999, M. Rayton // above confl. Sable Cr., trib. Meadow Creek, T29N R10E S09 SE SE NE, elev. 3360 ft. (1 P, CIDA; 1 P, EMEC; 1 P, WFBM); Nez Perce NF, Surveyor Cr. at Hwy. 14 nr. mm 27, 4.5 rd. mi. W Golden, 12-VII-2007, C. B. Barr // trib. S. Fk. Clearwater R., elev. 3186 ft., 45°47.691′ N, 115°45.563′ W (16 P, 2 NP, EMEC); 4.5 mi W Golden, 12 VII 07, 3186′, Surveyor Creek // William D. Shepard, leg. (4 P, 16 NP, WDSC). Lemhi Co.: Salmon NF, Bear Basin Cr. above FS Rd. 030, 29-VII-1996, C. Fischer // trib. Salmon River, elev. 3000 ft., T23N R13E S13 NEQ (2 NP, CIDA; 1 P, EMEC; 1 P, WFBM); Salmon Natl. Forest, Elk Creek 20 m above Hwy. 93, elev. 5060′, 14-VII-1997, Overfield // trib. N.Fk. Salmon R., 45°36′08.98″N, 113°57′53.35″W (1 P, EMEC). Shoshone Co.: St. Joe Natl. Forest, Engstrum Creek, trib. Mica Creek, 2-VII-1992, J. White (1 NP, EMEC); Hammond- Kyle mid trib, -115.7689, 47.3121, 05 JUL 2002, 0915 m, D.L. Gustafson, W1673 (1 P, MTEC); trib. Merry Cr. at FS Rd. 226/758 nr. Davies Pass, 8.6 rd. mi. NE Clarkia, 13-VII-2007, C. B. Barr // elevation 3552 ft., 47°04.704′ N, 116°09.128′ W (4 P, EMEC); 8.6 mi. NE Clarkia, 13 VII 07, 3852′, trib of Merry Cr // William D. Shepard, leg. (2 P, WDSC); 9 mi NE Clarkia, 13 VII 07, 3553′, trib of Merry Cr // William D. Shepard, leg. (6 P, WDSC).

Distribution, Habitat, and Biology. Based on collection records, the range of this species extends from the lower “panhandle region” of northern Idaho, in an area from the St. Joe River in Shoshone County, southeast to the Salmon River in Lemhi County ( Fig. 10 ). This mountainous area includes the three main forks of the Clearwater

River in the counties of Clearwater and Idaho. In July 2007, I went to Idaho, along with Bill Shepard, to collect additional specimens and examine the habitat of B. idahoensis . We collected specimens at 13 localities, all of which are low-order, closedcanopy streams with cool to cold water, the largest at 1.5–3.0 m wide being Fern Creek, the type locality ( Fig. 11 ). Most of the sites are cold, high-gradient, first-order rivulets that are completely concealed from the road by plant cover. Sampling was also done in larger streams which lacked aquatic bryophytes, but these were unproductive for Bryelmis . When found at a site, specimens of B. idahoensis were often present in large numbers.

The majority of specimens were collected in association with aquatic bryophytes attached to rocks, although in some cases the beetles were also found on waterlogged wood. Bryophyte samples from eight sites yielded one species of liverwort and four species of moss. The liverwort Chiloscyphus polyanthos rivularis (Schrad.) Nees (Geocalycaceae) was present in six of the eight samples, and was exclusive in three. The most common moss, Platyhypnidium riparioides (Hedwig) Dixon (Brachytheciaceae) , was present in two samples, and the other three moss species were present in one sample each. Bryelmis idahoensis specimens were collected from waterlogged wood at four localities and were common at two; aquatic bryophytes also occurred at three of these sites. Two specimens borrowed for this study were collected in a “pitfall trap in moist old growth cedar forest”...“in a very damp area within several meters of running water” (Isabella Creek) (F. Merickel, in litt.).

I recorded the following elmid species co-occurring with B. idahoensis at one or more of the collecting localities: C. addenda , Heterlimnius corpulentus (LeConte) , Lara avara LeConte , Narpus concolor LeConte , Optioservus quadrimaculatus (Horn) , and Z. posthonia . In the smaller streams, B. idahoensis was usually the only elmine present, but was sometimes accompanied by L. avara , a laraine elmid that is typically associated with wood and woody debris ( Brown 1972).

Etymology. The species is named for the state in which it occurs, Idaho, plus –ensis, a suffix denoting place or locality. The origin of the name Idaho is contested.

Figures

Figs. 3–4. Habitus of Bryelmis idahoensis. a) Dorsal, b) Lateral. Scale bars = 0.5 mm.

Figs. 5–7. Male genitalia of Bryelmis spp. 5) B. idahoensis, dorsal view; 6) B. siskiyou, dorsal view; 7) B. rivularis, a) Dorsal view, b) Lateral view.

Fig. 10. Known distribution of Bryelmis spp. in North America: B. idahoensis (circles), B. rivularis (squares), and B. siskiyou (triangles).

Figs. 11–13. 11) Fern Creek, Clearwater Co., ID, type locality of Bryelmis idahoensis; 12) Dragsaw Spring, Humboldt Co., CA, habitat of Bryelmis siskiyou; 13) Hell Roaring Creek, Jefferson Co., WA, type locality of Bryelmis rivularis.

Figs. 8–9. Habitus of Bryelmis spp. 8) B. rivularis, a) Dorsal, b) Lateral; 9) B. siskiyou, a) Dorsal, b) Lateral. Scale bars = 0.5 mm.