Isoperla marmorata
Creators: name: Sandberg, John B.
name: Kondratieff, Boris C.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Plecoptera
Perlodidae
Isoperla
Isoperla marmorata

description: <i>Isoperla marmorata</i> (Needham &amp; Claassen) (Figs. 8 a-d, 20 c) <i>Clioperla marmorata</i> Needham &amp; Claassen 1925. Holotype &amp;female;, Nevada. <b>Male</b>. Aedeagus: sclerotized posterior process present; body with one small posterior lobe, one dorsal lobe and an anterior lobe (Fig. 8a); one small patch of spinulae concentrated on the inverted membrane above sclerotized process (Figs. 8 a-b); sclerotized process approaching 0.5 mm when fully extended, blade-like in lateral view (Fig. 8a), distal margin thin in posterior view (Fig. 8b), and narrow proximal portion of sclerotized process usually inverted inside posterior aedeagal membrane. Abdominal terga 8-9, 9, 9-10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering gradually to long blunt apices (Fig. 8c). Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 8d). The aedeagus of <i>I. marmorata</i> is more similar to <i>I. fulva</i> than to <i>I. roguensis</i> with similar numbers of spinule patches, patch shapes and positions. The <i>I. marmorata</i> aedeagus possesses two anteroapical small areas of inverted membrane which form the bases of the internal tube-like structures. Additionally, a pair of very small holes is present on the dorsal surface, usually on a minute lobe (not visible in Figs. 8a &amp; 8c). The pairs of inverted membrane areas and minute holes occasionally have fixed streaming seminal fluid still attached. The previous <i>I. marmorata</i> aedeagal description did not include extended apical tube-like lobes (Szczytko and Stewart 1979, fig. 123). After clearing the everted aedeagus in KOH, a pair of inverted tube-like processes were observed within the aedeagus and attached to the small inverted areas (openings) upon the anteroapical margin (Fig. 20c). It is possible that the previous description was based upon a live everted male that was not cleared. <i>Isoperla marmorata</i> wing and body color varies significantly in California. Typically at lower elevations and into the foothills, abdominal coloration is mostly yellow (reddish-yellow in life) and hindwing anal areas are lightly tinted. An exception occurs at Butte Creek (near Chico) where both wings are completely tinted and males have a dark wide ventral band on the ninth sternum. At a higher elevation Big Chico Creek location (Tehama Co.), the abdomen is yellow with multiple brown markings and dark wings. An extreme adult phenotype of this species is found at Prairie Creek (Humboldt Co.) where the abdomen is almost completely brown and the wings nearly black (J.J. Lee, pers. com.). <b>Additional Material Examined.</b> CALIFORNIA, Siskiyou Co., McCloud River, Hwy 89 Lower Falls Picnic Area 5.5 (8.8 km) mi E McCloud, 41.2402°N, 122.02441°W, 23/ V /2013, J.B. Sandberg, B.C. Kondratieff, 3&amp;male;, 1&amp;female; (JBSC). OREGON, Lake Co., Deep Creek, Hwy 140, 5.5 mi (8.8 km) E Adel, 42.18564°N, 119.99512°W, 20/ V /2013, J.B. Sandberg, B.C. Kondratieff, 4&amp;male;, 2&amp;female; (JBSC).
description: Published as part of <i>Sandberg, John B. &amp; Kondratieff, Boris C., 2013, The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species, pp. 34-64 in Illiesia 9 (5)</i> on page 49, DOI: 10.5281/zenodo.4760870
description: {"references": ["Needham, J. G. &amp; P. W. Claassen. 1925. A monograph of the Plecoptera or stoneflies of America north of Mexico. Thomas Say Foundation, 397 pp.", "Szczytko, S. W. &amp; K. W. Stewart. 1979. The genus Isoperla (Plecoptera) of western North America; Holomorphology and systematics, and a new stonefly genus Cascadoperla. Memoirs of the American Entomological Society, 32: 1 - 120."]}