Stonefly Species Oroperla barbara (Gilltail Springflies)

Source: A Compendium Of Distributional Records For Oroperla Barbara Needham, 1933 (Plecoptera: Perlodidae), With Additional Documentation Of Reproductive Morphology And Biology

Adult habitus [Previously described by Jewett (1966)]. Male forewing length 15.0 mm (n = 1); female forewing length 19.0 - 20.5 mm (n = 3). Body dark brown, wings transparent with dark veins. Head dark brown with yellow markings; pronotum dark with a narrow, median yellow stripe. Antennae brown, cerci pale brown (Fig. 1). Abdominal gills present on ventrolateral corners of segments 1 - 7 (Fig. 9). Male epiproct and 10 th tergal complex [Previously described by Jewett (1966)]. Hemiterga of tergum 10 attenuated to form digit-like curved structures (Fig. 3). Black, Y-shaped, prominent epiproct anchor located anteromedially between hemiterga, and a large membranous cowl extends posteriorly enclosing epiproct. Epiproct bent sharply at a near right angle at posteroventral region of cowl (Fig. 4); most of epiproct very darkly sclerotized within cowl, but a short apical section lacks strong sclerotization. Much of epiproct surface covered with fine, densely packed setae. Epiproct tip in lateral aspect slightly excavated and not quite as wide as the more basally located and heavily sclerotized section. In dorsal aspect, a pair of darkly sclerotized paragenital plates are imbedded in the membranous cowl. Lateral stylets not evident. Aedeagus glabrous and recurved over terminal abdominal segments (Fig. 8). Dorsal aspect narrow, expanding into large, lateral lobes, narrowing abruptly with a rounded apex (Fig. 7). Lateral aspect with relatively constant width from base to anterior lobes, apex pointing downward and terminating in rounded tip (Figs. 8 - 9). Female subgenital plate [Previously described by Siegfried et al. (1977)]. Subgenital plate broad basally, narrowed apically and bearing a variably shaped shallow median notch (Figs. 5 - 6). Most of sternum 9 membranous, but posterior margin bearing a slender, black, transverse sclerite. Midlateral membranous field of sternum 9 also bearing a pair of subtriangular sclerites.

Egg (n = 8) [Previously described by Siegfried et al. (1977) and Stark & Szczytko (1984, 1988)]. Total length 623 µm, egg body length 561 µm, egg collar length 62 µm, egg diameter 419 µm, collar diameter 129 µm (Figs. 10 - 12). Chorionic surface covered throughout with hexagonal follicle cell impressions (FCI) (Figs. 10 - 15). Thick FCI walls surround a single, or a pair of pits (Fig. 15). FCI width near micropylar region 16 - 19 µm. Micropyles form irregular rows near mid-length; orifices small and often surrounded by rosettes composed of modified FCI’s (Fig. 15). Anchor hat-shaped with turned up brim (Fig. 13).