Stonefly Species Bolshecapnia gregsoni (Little Snowflies)

Source: A Review Of The Genus Bolshecapnia Ricker, 1965 (Plecoptera: Capniidae), And Recognition Of Two New Nearctic Capniid Genera

Male epiproct (n = 3). Length 544 - 593 µm, width at mid-length 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 mid-length 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.