Isoperla sordida Banks

(Figs. 16 a-d)

Isoperla sordida Banks 1906 .

Holotype ♂, California, Los Angeles.

Male. Aedeagus: sclerotized posterior process present; body of aedeagus with two posterior lobes, one dorsal lobe, and one anterior lobe (Fig. 16 a); sclerotized process length approaching 0.5 mm, partially recurved and rod-like, apex expanded, flattened and projecting dorsally in lateral view (Figs. 16a), bifurcate subapically with two ventrally directed rounded lobes in posterior view (Fig. 16b inset), width of lobes 0.18-0.20 mm. 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. 16c). Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 16d).

Isoperla sordida has been recently collected in two high elevation (above 1524 m), spring fed or snow melt eastern Sierra Nevada streams (Sandberg 2011b); and shares similar characters with other species from the I. sordida complex and I. umpqua (Table 1). It is most similar to I. denningi . See comments under I. denningi .