Figs 7–9.
Male. Body length of single known specimen 8.5 mm, length of each forewing 12 mm, width of each forewing 4.25 mm, length of each antenna 7.0 mm. Body, antennae, palpi, wings, abdomen and legs yellow.
Male genitalia (Figs 7–9). Apicodorsal lobe of segment IX (a.l.IX., Fig. 8) tapered to blunt apex in dorsal view. Segment X (X., Fig. 7) broad lobe with slightly concave dorsal margin and curved ventral margin in lateral view. Preanal appendages (pr. Figs 7, 8) longer than anal sclerites with distal ends bending over the anal sclerites in dorsal view. Anal sclerites (a.s., Figs 7, 8) each bifurcate with long straight stem, apical fourth grooved in dorsal view. First segment of each inferior appendage (f.s., Fig. 7) long, broad, longer than preanal appendages and shorter than phallicata; dorsal lobe of second joint of each inferior appendage (s.j., Fig. 7) shorter than ventral lobe, dorsal corner obtuse, ventral lobe twice as long as dorsal lobe with blunt apex and horizontal ventral margin, and with deep excavation between lobes in lateral view. Endotheca (end., Figs 7, 9) wide tube, narrowing anteriorly in lateral and ventral views; phallicata (ph., Figs 7, 9) long tube with robust base, slender in middle, terminating in wide excavated distal part with extended apex directed dorsocaudad in lateral view; parameres (par., Figs 7, 9) half as long as phallicata with three huge spikes of different length in lateral view, resembling spread wings in ventral view.
Female. Unknown.
Holotype: ♂, NEPAL, EAST-NEPAL, [Taplejung District] Kancanjanga Himal, 6 km S of Ghunsa 27 o 39 ’N, 87 o 48 ’E, 4160 m elevation, by light trapping, 14 August 2000, leg. Tibor Csővári and Márton Hreblay (gen. prep. No. 122, Ottó Kiss, coll. Mátra Museum).
Differential d iagnosis. This subspecies of R. chayulpa belongs to the Rhyacophila chayulpa Group of the R. divaricata Branch (Schmid 1970). The male genitalia of this species are similar to those of Rhyacophila chayulpa ringmo Schmid 1970 (plate XXXV, figs 11–12) from Driang Dzong, Kameng, India, and R. chayulpa tsetangpa Schmid 1970 (plate XXXV, figs 9–10) from Tarsali, Gharwal, India, but differs from them in that:
1. The preanal appendages are longer than the anal sclerites (not shorter as in R. chayulpa ringmo or R. chayulpa tsetangpa).
2. The anal sclerites are bifurcate with long, straight margins and with apical fourth grooved (not with curved margins without grooves as in R. c. ringmo or in R. c. tsetangpa).
3. The phallicata is golf-club-shaped (not blade-shaped as in R. c. ringmo or R. c. tsetangpa).
4. Each paramere has 3 huge spikes of different lengths (not a row of long hairs as in R. c. ringmo or R. c. tsetangpa).
Etymology. Named for the place where the new subspecies was collected.