Bolshecapnia gregsoni ( Ricker, 1965 )

Broome, Hannah Jean, Stark, Bill P. & Baumann, Richard W., 2019, A Review Of The Genus Bolshecapnia Ricker, 1965 (Plecoptera: Capniidae), And Recognition Of Two New Nearctic Capniid Genera, Illiesia 15 (1), pp. 1-26 : 6-9

Bolshecapnia gregsoni ( Ricker, 1965)

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org: TaxonName:5037

( Figs. 1-6 )

Capnia (Bolshecapnia) gregsoni Ricker, 1965:479 .

Holotype ♂ (Canadian National Collection), Kokli Lake between Mount Arrowsmith and Mount Kokli Vancouver Island, British Columbia

Bolshecapnia gregsoni: Ricker & Scudder, 1975:338

Distribution. CANADA: BC ( DeWalt et al. 2018)

Material examined. CANADA: British Columbia: Kokli Lake, between Mount Arrowsmith and Mount Kokli, near Cameron Lake, Vancouver Island , 9 June 1957, F. Neave, W.E. Ricker, Holotype ♂, 21 paratypes (CNC). Lake on Mount Arrowsmith, Vancouver Island , 9 June 1957, F. Neave, W.E. Ricker, 1♂, 1♀ (INHS, paratypes). Head of Gwillim Creek near Glacier Lakes, near Camp 3 on Gladsheim Massef, NW of Slocan City, 22-31 July 1958, J. Ricker, 1♀ (CNC). Garibaldi Lake, Spring Glacier on new snow, 18 April 1966, K. Ricker, N. Hansen, M. Shakespeare, 2♂, 1♀ (CNC). Garibaldi Park , 14 May 1958, J. Ricker, 6♂, 2♀ (CNC). Helen Lake , Garibaldi Park , 12 May 1951, J. Barton, 1 ♀ (CNC). Mount Alava Base Camp Snowfields , 24-31 July 2010, J. Cullington, 6♀ (RBCM) .

Male epiproct (n = 3). Length 544-593 μm, width at midlength 185-213 μm, greatest width near base 147-253 μm. A pair of curved, acute, sclerotized hooks arise from either side of the median groove at about half the distance between the epiproct apex and the base of the spongy area from either side of the median groove. The hooks extend slightly beyond lateral margins of the epiproct body ( Figs. 1-3 ), and their tips reach to about 0.8 of the epiproct length. Median groove wide near apex and narrowed near dorsobasal knobs ( Fig. 4 ). Median groove divides a pair of spongy-appearing clumps of tissue near hooks ( Fig. 2 ). Apex without a protruding membranous process; dorsobasal humps low, smooth and not outlined by a prominent posterodorsal ridge ( Fig. 2-3 ). Paraprocts with a hairy, plate-like basal area and slender apices.

Tergal process (n = 3). Absent, but tergum 9 bears a median patch of short, thick setae ( Fig. 1 ) and lacks a median anterior notch. However, tergum 10 bears a median anterior notch filled with membranous tissues projecting into the notch from tergum 9 ( Fig. 7 ).

Vesicle (n = 1). Length 305 μm, width at midlength 311 μm, basal stalk short and 168 μm wide. Surface entirely covered with thick setae except for the short stalk that extends under the basal roll of tissue ( Fig. 4 ).

Female subgenital plate (n = 2). This structure is a triangular plate that extends beyond the anterior margin of sternum 9 (see fig. 10 in Ricker 1965, fig. 173 in Baumann et al. 1977, and fig. 3.12 in Stewart & Oswood 2006). The images we present show an almost triangular plate, rounded and glabrous at the apex with convergent lateral margins ( Figs. 5- 6 ). The transverse striations observed on the subgenital plate in Fig. 6 may be an artifact of dehydration.

Larva. Unknown.

Comments. The figures and descriptions of the male of this species by Ricker (1965) and Stewart & Oswood (2006), and our SEM figures indicate that it is related to B. milami and B. spenceri . Ricker (1965) states the species “…is closely related to C. spenceri … ”. The two species are thought to be allopatric in British Columbia with the western limit of B. spenceri extending into the Selkirk Mountains and the eastern limit of B. gregsoni extending to the Valhalla range ( Ricker 1965). According to Ricker (1965) the major distinction between B. gregsoni and B. spenceri males is the presence of a “deep groove” that extends posteriorly from the midpoint of tergum 9 in males of the latter; females of B. spenceri have a very narrow, and often asymmetrical, subgenital plate (figs. 15-16 in Ricker 1965). Males of these species each have epiprocts with a pair of sharply pointed, sclerotized hooks near midlength and conspicuous, spongy-appearing dorsal patches of anterolateral tissue ( Figs. 3 , 9 , 21 , 28 ), consequently these two capniid species have the distinction of being relatively easy to distinguish as females and somewhat more difficult to distinguish as males. The epiprocts of B. milami differ from the other two species in having a downturned mesoapical hook. The original material of B. gregsoni reported by Ricker (1965) includes 21 ♂ and 30 ♀ specimens; most of these were collected from Vancouver Island at “…sites at or near high mountain lakes” ( Ricker 1965).

Figures

Figs. 1-6. Bolshecapnia gregsoni, male and female reproductive structures. All localities in British Columbia. 1. Garibaldi Provincial Park, male epiproct and terminal abdominal segments, dorsal. 2. Garibaldi Provincial Park, epiproct dorsal. 3. Garibaldi Provincial Park, epiproct lateral. 4. Garibaldi Provincial Park, vesicle ventral. 5. Mt. Arrowsmith, Vancouver Island, female terminal abdominal segments. 6. Mt. Arrowsmith, Vancouver Island, female subgenital plate (sgp = subgenital plate; tn = tergal notch; ve = vesicle).

Figs. 7-12. Bolshecapnia milami, male reproductive structures. All localities in Montana, Lake Co., Lion Creek. 7. Male epiproct dorsal. 8. Epiproct apex dorsal. 9. Epiproct and tergal process dorsal. 10. Epiproct lateral. 11. Epiproct base dorsal. 12. Epiproct apex dorsal. (af = anterolateral fold; ah = anterior hook; as = anterior section; bh = basolateral hook; bs = basal section; mg = median groove; or = orifice; sa = spongy area; tp = tergal process).

Figs. 19-24. Bolshecapnia milami, reproductive structures, localities 19-22 in Colorado, Chaffee Co., Chalk Creek, and 23-24 in Wyoming, Albany Co., Libby Creek. 19. Male epiproct dorsal. 20. Epiproct lateral. 21. Epiproct apex lateral. 22. Male abdominal sternum 9 and vesicle (ve = vesicle). 23. Epiproct dorsal. 24. Epiproct lateral.

Figs. 25-30. Bolshecapnia spenceri, male reproductive structures. All localities in Montana, Glacier Co., Iceberg Lake. 25. Male epiproct and terminal abdominal segments dorsal. 26. Epiproct dorsal. 27. Epiproct dorsal. 28. Epiproct apex dorsal. 29. Epiproct lateral. 30. Epiproct apex lateral.