Sweltsa salix, Lee & Baumann, 2010

Lee, Jonathan J. & Baumann, Richard W., 2010, Studies On Sweltsa Townesi And A New Species, Sweltsa Salix, From Northern California (Plecoptera: Chloroperlidae), Illiesia 6 (4), pp. 34-40 : 38

Sweltsa salix sp. n.

( Figs. 9-16 )

Material examined. Holotype ♂ from California, Humboldt Co., Willow Creek, East Fork Willow Creek Campground , 19-V-08, J.J. Lee . Paratypes: - CALIFORNIA: Humboldt Co., Willow Creek, Hwy 299, East Fork Willow Creek Campground , 22-VI- 1985, R.W. Baumann, C.R. Nelson & M. L. Whiting, 2♂, 1♀ ( BYUC) ; 2-V 1-2007, J.J. Lee, 3♂, 13♀ ( BYUC) ; 5-VI-07, J.J. Lee, 4♂, 2♀ ( JJLC) ; 19-V-08, J.J. Lee, 21♂, 10♀ ( BYUC, JJLC) ; 25-V-09, J.J. Lee , 1♂, 3 nymphs, 1♂, 6♀ reared, 26-28-V-09 ( JJLC) ; spring, East Fork Willow Creek Campground , 19-V-08, J.J. Lee, 1♂ ( JJLC) ; 28-V-2008, J.J. Lee, 2♂, 3♀ ( JJLC) . Siskiyou Co., McCloud River, Fowlers Campground , 6-VI-1965, S.G. Jewett, Jr., 2♂, 2♀ ( BYUC) ; McCloud River, Hwy 89, Falls of the McCloud River , 25-V-2007, R.W. Baumann & B.C. Kondratieff, 103♂, 61♀, ( BYUC, CSUC) ; Scott River, Scott River Road , Bridge Flat, J.J. Lee, 1♂ ( BYUC) . Trinity Co., East Weaver Creek, East Weaverville Campground , 6-VI-2005, R.W. Baumann & B.C. Kondratieff, 1♂, 4♀ ( BYUC) . Holotype deposited at the California Academy of Sciences .

Male. Macropterous; body length 6.5– 8 mm, forewing length 6.5-7.5 mm. General color dusky yellow with brown markings. Head yellow, ocellar rings dark brown, brown M mark forward of anterior ocellus evident to varying degrees. Pronotum wider than long, margin dark brown, widest laterally, brown rugosities lateral of median line. Meso-metanota with dark U mark. Abdominal terga 1-8 with median brown stripe, stripe terminates on tergum 8 as an oval mark on anterior one-half; lateral dark patches anteriorly on segments 1-4; anteromedial transverse, anteriorly sclerotized, scalloped ridge on tergum 9 (Figs. 11,12). In dorsal aspect (Figs. 9,11) epiproct tip spatulate, chocolate brown, length more than twice greatest width, median shallow channel at base gradually widens anteriorly ( Fig. 13 ), anteromedial carina divides channel at midpoint, carina terminating as a raised knob short of apex ( Figs. 10- 12 ). In lateral aspect ( Fig. 12 ) epiproct tip narrow at base expanding to a bulbous club distally, dorsal margin appearing slightly convex in proximal twothirds before sloping upwards (carinate process) forming the apical club, ventral margin appearing nearly straight before sloping upwards to form apical club. Aedeagus membranous ( Figs. 15, 16 ), tubular basally, roughly triangular in dorsal aspect, posterolateral lobes appear slightly infolded, posteromedial margin with pair of small, elongate finger-like lobes, dorsal face bearing transverse, striate ridge, peaked medially, ventral face with median basal lobe and pair of smaller distolateral lobes.

Female. Macropterous; body length 7.5- 9 mm; forewing length 8.5- 9 mm. General body color and markings similar to male but median brown mark on tergum 8 mostly restricted to anterior margin. Subgenital plate crudely hexagonal ( Fig. 14 ), wider than long, elevated anteriorly and centrally, hirsute, extending at least one-half over sternum 9.

Larva. Characters for mature larva similar to description for S. townesi (Stewart and Stark 2005) although M-line centered on anterior ocellus is pale in specimens not exhibiting adult coloration beneath cuticle.

Etymology. The species epithet salix is based on the Latin word for willow. This not only has reference to the fact that the types were collected from Willow Creek but also that the adults are often found on streamside willows (Salix spp.).

Diagnosis. Sweltsa salix is closely related to S. townesi but they can be separated by the male epiproct. The epiproct of S. townesi possesses a distinct dorsomedial narrow groove extending from the base to near the apex ( Figs. 1-5 ). The epiproct of S. salix possesses a broad, shallow dorsomedial channel extending from the base and bisected apically by a carinate knob ( Figs. 9-13 ). The aedeagus of the two species is very similar in shape. Females can not be separated without associated males.

Distribution. Present collection records of S. salix indicate an interesting distribution pattern in the California Coast Range. It was collected from Willow Creek and East Weaver Creek, both medium sized tributaries of the Trinity River, and from the Scott River, a small river flowing into the middle Klamath River. Sweltsa salix was also collected on the east side of the Sacramento Valley from the McCloud River. We suspect it occurs in medium sized creeks and small rivers throughout the Klamath-Trinity watershed, however, a thorough search of material at BYUC did not produce S. salix specimens from streams adjacent to the McCloud River.

Figures

Figs. 9-16. Sweltsa salix, male and female genitalia and aedeagus. Willow Creek, East Fork Willow Creek Campground, CA. 9. male terminalia, dorsal; 10. epiproct, apex, dorsal; 11. epiproct, dorsal; 12. epiproct, lateral; 13. epiproct, base, dorsal; 14. female, subgenital plate, ventral; 15. aedeagus, dorsal; 16. aedeagus, terminal.

Figs. 1-8. Sweltsa townesi, male and female genitalia and aedeagus. 1. epiproct, dorsal, S F Stanislaus River, CA; 2. epiproct, apex, dorsal, S F Stanislaus River, CA; 3. epiproct, lateral, Galena Creek, NV; 4. epiproct, dorsolateral, S F Stanislaus River, CA; 5. epiproct, base, dorsal, S F Stanislaus River, CA; 6. female, subgenital plate, ventral, S F Stanislaus River, CA; 7. aedeagus, dorsal, Galena Creek, NV; 8. aedeagus, terminal, Galena Creek, NV.