Rhyacophila septentrionis, McLachlan, 1865

Rhyacophila septentrionis

MALE

Biometrics: Lengths: Body (distance from front of head to distal edge of segment IX): 7.8–13.0 mm (x̄ = 10.3, n = 27), forewing 10.1–15.8 mm (x̄ = 12.8, n = 27), hind wing 9.1–14.2 mm (x̄ = 11.3, n = 27).

Genitalia ( Figs 19 View FIGURES 19–20 , 23 View FIGURES 23–25 ): 2nd segment of each inferior appendage ( Figs 19A View FIGURES 19–20 , 23a View FIGURES 23–25 ) with posterior edge slightly concave in dorsal area, ventral edge straight or slightly concave, ~ 2.2 times longer that dorsal edge; apicodorsal vertex of 2nd segment ~ 120º and angled, apicoventral angle ~ 40°, projecting as thick lobe tapering to apex.

Parameres in ventral view curved posteromesad in distal half ( Figs 19 View FIGURES 19–20 BV, p; 23c). In lateral view ( Figs 19 View FIGURES 19–20 BL, 23d) each constricted 1/3 distance beyond base, dilated at middle, with round dorsal and ventral margins; without spines along midventral margin; midlateral surface with few long and thick spines on ventral area and fine spicules or setae from middle to ventral edge, absent in middle anteroventral and posterodorsal edges. Aedeagus (phallicata) in lateral view ( Fig. 19 View FIGURES 19–20 CL) with anterodorsal margin and posterior corner of dorsal concavity hooked anterad, apical edge of aedeagus straight projected posteroventrad in small ventral apex ( Fig 19 View FIGURES 19–20 CL); ventral lobe of aedeagus semicircular, with small posterior apex ( Fig 19 View FIGURES 19–20 BV, vl), in lateral view vertical edge straight, small projection in posteroventral angle ( Fig. 19 View FIGURES 19–20 CL). In dorsal view posterior edges of lateroventral lobes of phallus apically straight or slightly convex, apicolateral margins round ( Fig 19 View FIGURES 19–20 CD, lvl).

Apicodorsal lobe of segment IX in dorsal view dilated subapicolaterally ( Figs 19 View FIGURES 19–20 DD, al; 23b), with small apicomesal excision; preanal appendages ( Fig 19 View FIGURES 19–20 DD, pa) round, 4/5 as long as apicodorsal lobe, round subapically and posterior edges convex. In ventral view, apical band ( Fig 19 View FIGURES 19–20 DV, ab) V-shaped, longer than wide, its posterior arms converging, parallel and round apically, its non-sclerotized mesal area slightly oval, narrow ( Fig 19 View FIGURES 19–20 DV, va), anal sclerites triangular, posterior edges concave ( Fig 19 View FIGURES 19–20 DV, as).

FEMALE

Biometrics: Body length (distance from front of head to distal edge of segment VIII): 9.5–13.1 mm (x̄ = 11.3, n = 11), forewing 11.7–15.6 mm (x̄ = 13.1, n = 11), hind wing 10.1–13.8 mm (x̄ = 11.5, n = 11).

Genitalia ( Figs 20 View FIGURES 19–20 , 26 View FIGURES 26–28 ): In lateral view ( Figs 20L View FIGURES 19–20 , 26L View FIGURES 26–28 ), posterior margin of segment VIII valves on each side triangular, truncated posteriorly, with a dorsolateral projection, posterodorsal margins slightly concave, posteroventral margins slightly convex, posterior margin straight, with small excision in the middle. In dorsal view ( Figs 20D View FIGURES 19–20 , 26D View FIGURES 26–28 ), with indentation between segment VIII valves nearly enclosed by pair of dorsolateral triangular projections, with rounded apical and subapical corners, delimiting oval space. In ventral view ( Figs 20V View FIGURES 19–20 , 26V View FIGURES 26–28 ) segment VIII valves forming two elongate sclerites, concave, diverging and separated basally; intersegmental membrane with pair of dark, slightly elongate sclerites.