Stonefly Species Isoperla baumanni (Yellow Sallies)

Source: The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species

(Figs. 1 a-d, 2 c, 5 a-h, 20 c)

Source: The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species

Male larva. Body length of mature larva 9 – 10 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus usually connected to light frontoclypeus area by an apically narrowed median longitudinal light band, its width at mid length approximately equal to the width at base, lateral arms with irregular margins usually disconnected from median light band, directed posterolaterally, and extending to antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area partially light, completely enclosed by dark pigment, light area extending past posterior ocelli, not reaching dark pigment below the arms of the epicranial suture, light area generally oval shaped with acutely constricted base; occiput with irregular spinulae band extending from below eye to near median epicranial suture, completely enclosed by dark pigment (Figs. 1 d, 5 a). Lacinia bidentate, total length 1069 – 1256 µm (Figs. 1, 2 c, 5 e- h, Tables 2 - 4); submarginal row (A + B) with 7 – 10 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 5 g); 5 – 7 submarginal setae (A) in a close set row beginning at base of apical tooth (AT), ending before reaching SAT inner margin, row usually single, rarely 2 setae thick, plus 1 thin marginal setae (TMS) adjacent to AT inner margin, sometimes obstructed from view by the AT, submarginal setae (A), or broken, and 1 dorsal seta (DS) located below SAT inner margin, sometimes obstructed from view by SAT, submarginal setae (B), or broken (Fig. 5 h); 2 – 4 submarginal setae (B) located past SAT inner margin (Figs. 5 g-h); 15 – 27 marginal setae (C) initially long stout and widely spaced, usually several setae near end of row arranged in pairs protruding at dorsal and ventral angles, last few shorter and closer, blending into and difficult to differentiate from dorsal surface setae (Fig. 5 e); 38 – 71 ventral surface setae (D) scattered below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, occasionally a few setae below submarginal row striated (Fig. 5 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band, concentrated at junction with marginal setae (C), ending at approximately ½ or a little more the lacinia length (Fig. 5 e). Galea with 15 – 33 setae in sparse ventral row, apex with 2 – 3 setae. Maxillary Palp segments 2 – 3 with curved apically rounded setae (Fig. 5 e Inset). Pronotum with broad median light area bordered by thick dark comma shaped bands typical of the Isoperla sobria complex; discs each with thick black clothing setae, those along median margins usually enclosed by indistinct light brown pigment, lateral margins with broad light bands (Fig. 5 b). Mesonotum and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 5 c). Legs with numerous fine golden clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated along dorsal surfaces; fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 c); tibia with faint transverse bands near proximal end. Abdominal terga with three longitudinal dark stripes; wide light median longitudinal band bisected with thin light brown median longitudinal stripe present on distal segments; lateral pair of dark longitudinal stripes about twice as wide as median dark stripe, extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 5 d).

Source: The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species

Male. Aedeagus: sclerotized posterior process absent; body with one posterobasal lobe, one posteromedian lobe and expanded apex, apex deeply inverted (Fig. 3 a); one large patch of spinulae concentrated below posteromedian lobe (Fig. 3 b), and a long thin patch along posteroapical margin (Fig. 3 c). 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 first cercal segment, tapering abruptly to blunt apices (Fig. 3 c). Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 3 d).