Sierracapnia Bottorff &amp; Baumann 2015, new genus
Creators: name: Bottorff, Richard L.
name: Baumann, Richard W.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Plecoptera
Capniidae
Sierracapnia

description: <i>Sierracapnia,</i> new genus <b>Type Species.</b> <i>Sierracapnia barberi</i> (Claassen 1924). <b>Adults.</b> Body length 5-7 mm; color dark brown to black; wings macropterous, forewing R1 vein curved forward near origin of RS vein and A 1 curved beyond crossvein a; cerci long, 14-18 segments. Ventral sclerites of adult thorax identical to those reported for <i>Arsapnia</i> and <i>Capnia s. s.</i> (Table 1 in Murányi et al. 2014). Drumming signals unknown. <b>Male.</b> Median knobs absent on terga 1-6; large median raised knob present on tergum 7; median knob absent on tergum 8; pair of smaller raised knobs present on tergum 9, located on each side of epiproct apex; tergal knobs densely covered with rounded tubercles of conical sensilla. Epiproct a single sclerotized member, elongated and laterally compressed, with a curved ventral keel (deep or shallow) positioned between tergum 9 knobs; pair of dorsolateral horns pointing anteriorly and with slightly divergent tips. Epiproct basal sclerite present (small to large) and fused to main epiproct sclerite; laterobasal sclerites large and fused to main epiproct sclerite. Epiproct base with a narrow or thick neck in lateral view. Epiproct apex thin, rounded, or wedge-shaped in dorsal view. Epiproct glabrous, except caudal setae present. Anterior half of epiproct surface covered with numerous shallow sensory pits, each with a small pointed projection in the center; sensory pits less abundant or absent from epiproct neck and base. Epiproct dorsal membrane extends longitudinally for more than one-half epiproct length; membrane linearly folded and with anterior eversible crest that expands or contracts in size. Subgenital plate broadly fused with sternum and tergum 9 (see Fig. 35 in Murányi et al. 2014 for definition of terms). Ventral vesicle absent. Fusion plate (Hanson 1946) a long narrow internal structure largely hidden behind broad triangular paraprocts that are covered with stout hairs or spines, fusion plate apex exposed with a small tubular opening that fits into epiproct base, retractoral plate a thin sclerite separated from fusion plate (Figs. 4, 12, 32, and see Figs. 23 -31 in Murányi et al. 2014). <b>Female.</b> Subgenital plate large and heavily sclerotized, covering all of sternum 8 and posterior margin of sternum 7; division line between sterna 7 and 8 not always obvious; posterior margin of plate broadly truncated at posterior edge of sternum 8, plate not projecting onto sternum 9. Dorsum of abdominal segments 1-8 with median membranous band; posterior margin of segment 8 with small median V-shaped sclerite. 14-15rounded18-2425-30light18-2185-88narrow <b>Larva.</b> Unknown. <b>Diagnosis.</b> Murányi et al. (2014) provided a diagnosis of <i>Capnia s. s.</i> Pictet 1841 and concluded that eight species, primarily from the Palaearctic, were included in this restricted concept of the genus. <i>Capnia nearctica</i> Banks 1919, the only Holarctic species, has a distribution in North America that includes Alaska and northwestern Canada (Nelson and Baumann 1989, Stewart and Oswood 2006, DeWalt et al. 2015). Males of <i>Sierracapnia</i> differ from <i>Capnia s. s.</i> by their epiproct and knobs on tergum 9. <i>Sierracapnia</i> males have an undivided epiproct with distinct dorsolateral horns and prominent knobs on tergum 9. <i>Capnia s. s.</i> males have an epiproct divided into upper and lower members, but lack dorsolateral epiproct horns and knobs on tergum 9. In addition, <i>Sierracapnia</i> males have a basal sclerite and large laterobasal sclerites fused to the main epiproct sclerite, whereas in <i>Capnia s. s.</i> the basal sclerite is vestigial and the laterobasal sclerites are divided from the main epiproct sclerite (Murányi et al. 2014). The retractoral plate is separated from the fusion plate in <i>Sierracapnia</i> males, but the retractoral plate is fused to the fusion plate in <i>Capnia s. s.</i> males. The subgenital plate of <i>Sierracapnia</i> female adults is broad, heavily sclerotized, and extends from sternum 8 to the posterior half of sternum 7, whereas in species of <i>Capnia</i> <i>s. s</i>. this plate is small and does not extend onto sternum 7. <i>Sierracapnia</i> and <i>Arsapnia</i> adults also differ. The glabrous epiproct of <i>Sierracapnia</i> males is laterally compressed and the ventral surface is most often deeply curved (less deeply curved in <i>S. palomar</i>), while for <i>Arsapnia</i> males the epiproct has a narrow apical tip, laterally expanded bulb-like midsection (often with a row of stiff setae or spines), narrowed posterior neck, and straight ventral surface (Figs. 209-210 in Nelson and Baumann 1989). The epiproct of <i>Sierracapnia</i> males has a basal sclerite, but this sclerite is lacking or vestigial for <i>Arsapnia</i> males (Murányi et al. 2014). The dorsolateral horns of <i>Sierracapnia</i> are prominent, long structures that originate near mid-epiproct and project or arch forward about 15-30% of epiproct length. In contrast, the dorsolateral epiproct projections of <i>Arsapnia</i> are small, closely appressed to the main body, and confined to the anterior quarter. The dorsal epiproct membrane of <i>Sierracapnia</i> is often clearly exposed for over one-half of the epiproct length and the apex forms an eversible crest of linearly folded tissue that expands and contracts in size. In contrast, the epiproct dorsal membrane of <i>Arsapnia</i> is confined to a small, narrow area near the tip and the large eversible crest is absent. <i>Sierracapnia</i> males have well-developed knobs on tergum 9, with prominent rounded conical sensilla. These knobs are lacking on most species of <i>Arsapnia</i>, but tiny processes are present on three species: <i>A. pileata</i> (Jewett 1966), <i>A. teresa</i> (Claassen 1924), and <i>A. utahensis</i> (Gaufin and Jewett 1962). <i>Sierracapnia</i> female adults have a broad, heavily sclerotized subgenital plate that extends onto the posterior margin of sternum 7, while this plate is small and does not extend onto sternum 7 in <i>Arsapnia</i> females. Both <i>S. palomar</i> and <i>Arsapnia arapahoe</i> (Nelson and Kondratieff 1988) have linear or fusiform epiprocts that differ from the typical forms found in all other species of both genera. Yet each species has characters that are most similar with their respective genus. That is, <i>S. palomar</i> has a laterally compressed, glabrous epiproct with shallow ventral keel, a large basal sclerite fused to the epiproct, and a median dorsal groove that extends the full epiproct length (Figs. 13-15). In addition, median knobs are present on terga 7 and 9. In contrast, <i>A. arapahoe</i> has a slightly recurved epiproct that lacks a ventral keel (Fig. 4 in Nelson and Kondratieff 1988) and exhibits some dorsoventral flattening in the anterior third. Its median dorsal groove extends to one-half the epiproct length and a dorsal row of 4-6 anteriorly directed stiff setae or spines occur on each side of the median groove in the anterior third. A median knob is present on tergum 7, but the pair of knobs is absent from tergum 9. <i>Sierracapnia</i> demonstrates similarities with the three species of the <i>Capnia mariposa</i> species group sensu Nelson and Baumann (1989), especially with <i>C. giulianii</i> Nelson and Baumann 1987 and <i>C. mariposa</i> Nelson and Baumann 1987. In these two species, the epiproct exhibits varying degrees of lateral compression, a keeled ventral surface, dorsolateral horns, a large exposed dorsal membrane, and an eversible crest, plus tergum 9 has a pair of median knobs. Additionally, the <i>C. mariposa</i> species group is restricted to the Sierra Nevada. The <i>Capnia mariposa</i> group was excluded from <i>Sierracapnia</i> because all three species lack a knob on tergum 7 and the dorsolateral horns are small and restricted to the tip of the epiproct. The identification key for <i>Capnia</i> males in Nelson and Baumann (1989) separates <i>Sierracapnia</i> (then defined as the <i>C. barberi</i> species group) from nine other <i>Capnia</i> species groups and several unplaced species found in North America, but does not separate <i>Capnia</i> species groups found in the Palaearctic. With the exceptions noted above for three <i>Arsapnia</i> species, <i>Sierracapnia</i> differs from <i>Arsapnia</i> and all other <i>Capnia</i> species groups of North America by having distinct median knobs on terga 7 and 9, and lacking knobs on tergum 8. Further, except for two species of the <i>Capnia mariposa</i> group, <i>Sierracapnia</i> is unique among all other <i>Capnia</i> species groups of North America by having a laterally compressed epiproct. <b>Distribution.</b> The greatest diversity of <i>Sierracapnia</i> species is found in the Sierra Nevada; this includes <i>S. barberi, S. mono, S. shepardi,</i> and <i>S. yosemite</i> (Figs. 39, 40). Closely adjacent to the eastern Sierra Nevada, two species, <i>S. hornigi</i> and <i>S. washoe,</i> occur in the White Mountains and northwestern Nevada, respectively. The distribution of <i>S. barberi</i> extends northward into the southern Cascade Range. <i>Sierracapnia palomar,</i> which occurs on several mountains of southern California, lies outside the rather compact distribution of the other six species of the genus. In addition to the distributional separation of <i>S. palomar</i>, the shallow ventral curve and general linear proportions of its epiproct are obvious differences from the typical form of <i>Sierracapnia</i>. Nevertheless, this species was included in <i>Sierracapnia</i> because it bears knobs on terga 7 and 9 and its glabrous narrow epiproct has a ventral curved surface, dorsolateral horns, long membrane groove, and an apical eversible crest. The distributions of <i>Capnia s. s.</i> and <i>Sierracapnia</i> do not overlap in western North America: <i>Capnia s. s.</i> occurs in the far north; <i>Sierracapnia</i> is found much further south in California and Nevada. In contrast, overlap exists in the distributions of some <i>Sierracapnia</i> and <i>Arsapnia</i> since the latter has a wide range in western North America, occurring from the central and southern Rocky Mountains to the Coast Range. Members of several other <i>Capnia s. l.</i> species groups overlap broadly in their ranges with <i>Sierracapnia, Arsapnia</i>, and <i>Capnia s. s.</i> in western North America. <i>Sierracapnia</i> species inhabit midelevation, perennial, streams and creeks. <b>Etymology.</b> The name <i>Sierracapnia</i> reflects the primary Sierra Nevada distribution of the genus.
description: Published as part of <i>Bottorff, Richard L. &amp; Baumann, Richard W., 2015, Sierracapnia, A New Genus Of Capniidae (Plecoptera) From Western North America, pp. 104-125 in Illiesia 11 (9)</i> on pages 105-108, DOI: 10.5281/zenodo.4757677
description: {"references": ["Muranyi, D., M. Gamboa, and K. M. Orci. 2014. Zwicknia gen. n., a new genus for the Capnia bifrons species group, with descriptions of three new species based on morphology, drumming signals and molecular genetics, and a synopsis of the West Palaearctic and Nearctic genera of Capniidae (Plecoptera). Zootaxa, 3812: 1 - 82.", "Hanson, J. F. 1946. Comparative morphology and taxonomy of the Capniidae (Plecoptera). American Midland Naturalist, 35: 193 - 249.", "Nelson, C. R. and R. W. Baumann. 1989. Systematics and distribution of the winter stonefly genus Capnia (Plecoptera: Capniidae) in North America. Great Basin Naturalist, 49: 289 - 363.", "Stewart, K. W. and M. W. Oswood. 2006. The Stoneflies (Plecoptera) of Alaska and Western Canada. The Caddis Press, Columbus, Ohio.", "DeWalt, R. E., M. D. Maehr, U. Neu-Becker and G. Stueber. 2015. Plecoptera Species File Online. Version 5.0 / 5.0. [Accessed 30 April 2015]. .", "Nelson, C. R. and B. C. Kondratieff. 1988. A new species of Capnia (Plecoptera: Capniidae) from the Rocky Mountains of Colorado. Entomological News 99: 77 - 80.", "Nelson, C. R. and R. W. Baumann. 1987. New winter stoneflies of the genus Capnia with notes and an annotated checklist of the Capniidae of California (Plecoptera: Capniidae). Entomography, 5: 485 - 521."]}