Isoperla muir Szczytko &amp; Stewart 2004
Creators: name: Sandberg, John B.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Plecoptera
Perlodidae
Isoperla
Isoperla muir

description: <i>Isoperla muir</i> Szczytko &amp; Stewart (Figs. 2k, 13 a-h, 20 k) <i>Isoperla muir</i> Szczytko &amp; Stewart 2004, 130:234-236. &amp;male;, &amp;female;, larva (reared), ovum. <b>Material examined.</b> TYPE: <i>I. muir</i> Holotype &amp;male;, OR: <b>Douglas Co.</b>, Hwy 230, downstream from bridge, Muir Creek, 12/ V/2002, S. Szczytko, K. Stewart (reared with exuviae) (NMNH); <b>Additional Specimens.</b> OREGON: <b>Douglas Co</b>., Muir Creek, Muir Camp, Hwy 230 bridge, 13.5 mi (21.7 km) E Hwy 138 intersection, 27/V/2008, 31/V/2008, J. Sandberg, Larvae (reared). <b>Male larva. Body</b> length of mature larva 9–13 mm. <b>Dorsum of head</b> with contrasting pigment pattern and a mixture of fine light and dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus thin and well defined, not connected to light frontoclypeus area, median longitudinal light band absent, lateral thin arms directed posterolaterally, extending to antennal bases; posterior ocelli with completely enclosed small light areas along outer lateral margins; interocellar area entirely dark; occiput with irregular spinulae band extending from below eye to near median epicranial suture, enclosed completely by dark pigment (Fig. 13a). <b>Lacinia</b> bidentate, total length 724–837 µm (Figs. 2k, 13e- h, Tables 2-4); submarginal row (A+B) with 7–9 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 13g); 2 submarginal setae (A) the first inserted at base of apical tooth (AT) inner margin, the second located between AT and SAT inner margins, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT, submarginal seta (A), or broken, dorsal seta (DS) absent (Figs 13 g-h); 5–7 submarginal setae (B) located past SAT inner margin (Fig. 13g); 9– 11 marginal setae (C), initially long-stout and widely spaced, first marginal setae located under flap-like SAT inner margin (Fig. 13h – arrow), last few shorter and widely spaced (Fig. 13e); 33–58 ventral surface setae (D) forming dense longitudinal band below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, setae closest to inner margin protrude laterally past lacinia margin (Fig. 13f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending at approximately the posterior-most ventral surface setae (Fig. 13f). <b>Galea</b> with 22–32 setae in sparse ventral row, apex with 5–6 setae. <b>Maxillary Palp</b> segments 2–3 with nearly straight, apically rounded setae. <b>Pronotum</b> with thin indistinct median light line bordered by irregular dark longitudinal bands with adjacent light rugosites; discs each with brown comma shaped lateral areas, fine dark clothing setae and lateral margins without broad light bands (Fig. 13b). <b>Meso and metanotum</b> with contrasting pigment pattern and fine dark clothing setae (Fig. 13c). <b>Legs</b> with numerous fine dark clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated on dorsal surfaces; fine silky setae absent on dorsal surface of femora, sparse on tibia (Fig. 20k); tibia with very faint transverse bands near proximal end. <b>Abdominal terga</b> with two distinct longitudinal dark stripes; wide light median longitudinal band widest on middle segments, narrowing anteriorly and posteriorly; lateral pair of dark longitudinal stripes extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with distinct and scattered long, and numerous short spines in a concentrated row (Fig. 13d). <b>Distribution.</b> Oregon, known only from the type location (Szczytko &amp; Stewart 2004) where it occurs with <i>I</i>. <i>sobria</i>. <b>Diagnosis.</b> The mature male larvae of <i>I. muir</i> are most similar to <i>I. adunca</i> in that the submarginal row (A+B) setae form a continuous and regularly spaced row (Figs. 13 g-h). <i>Isoperla muir</i> can be separated from <i>I. adunca</i> by the submarginal setae row (A+B) regularly spaced at about the width of each seta base at points of insertion (Figs. 13a, g-h), dorsal seta (DS) absent and first marginal seta (C) covered by flap-like subapical tooth inner margin base (Fig. 13h). <b>Remarks.</b> This distinctively pigmented species is rarely collected and is apparently restricted to the type locality. Limited rearing indicated emergence occurred in June.
description: Published as part of <i>Sandberg, John B., 2011, The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species, pp. 202-258 in Illiesia 7 (22)</i> on pages 237-239, DOI: 10.5281/zenodo.4760320
description: {"references": ["Szczytko, S. W. &amp; K. W. Stewart. 2004. Isoperla muir, a new species of western Nearctic Isoperla and a new larval description of Isoperla tilasqua Szczytko and Stewart, (Plecoptera: Perlodidae). Transactions of the American Entomological Society, 130 (2): 233 - 243."]}