Capnia shasta Nelson and Baumann, 2009

Nelson, C. Riley, Baumann, Richard W. & Lee, Jonathan J., 2013, New Morphological Observations And Phylogenetic Placement Of Capnia Shasta (Plecoptera: Capniidae), Illiesia 9 (12), pp. 122-125 : 124

Capnia shasta Nelson and Baumann

( Figs. 1-8 )

Capnia umpqua Nelson and Baumann 1989:306 .

Capnia shasta Nelson and Baumann 2009:188 . Type locality, California: Shasta County, Sulphur Creek, Castle Crags State Park , N 41.15587 ° W 122.36285 °.

Material examined. California: Shasta Co., small tributary of Castle Creek flowing from north, above Castle Creek Road, approximately milepost 1.5, N 41.15614 ° W 122.35319 °, 18 February 2010, J.J. Lee, 4♂, 7♀ ( BYUC, JJLC) ; Sulphur Creek, Castle Crags State Park , N 41.15587 ° W 122.36285 °, 16 February 1985, R.W. Baumann & C.R. Nelson, holotype ♂ ( USNM) and 3♂, 4♀ paratypes ( BYUC) . Siskiyou Co., creek, mile 1.9, Salmon River Road, N 41.38061° W 123.46496°, 4 February 2011, J.J. Lee, 3♂, 4♀ ( BYUC, JJLC) ; 9 February 2011, J.J. Lee, 26♂, 12♀ ( BYUC, JJLC) .

Male. Epiproct with inflated dorsal process and shorter ventral process. Other features as in original description by Nelson & Baumann (2009). When fully visible anteriorly, the epiproct has the appearance of a small bird with its gape wide open ( Figs. 1-8 ).

Discussion. Nelson (2004) included four species of Capnia in the C. ventura species Subgroup of the C. californica Group: Capnia kersti Nelson , C. regilla Nelson and Baumann , C. saratoga Nelson and Baumann , and C. ventura Nelson and Baumann. We are including C. shasta in the C. ventura Subgroup based on the epiproct structure. Capnia shasta can be distinguished from the other subgroup members by features given in Nelson and Baumann (2009) and by the short lower process of the epiproct described herein.

Phylogeny. The cladogram given as Fig. 10 in Nelson and Baumann (2009) showed C. shasta as part of a polytomy with members of the C. californica Group. This hypothesis needs to be re-evaluated based on the actual state of the epiproct of C. shasta presented herein. With the recognition of the lower process of the epiproct, three characters in the matrix of Nelson and Baumann (2009) must be recoded: character 5 changes from 1 to 0 by redefining the appropriate upper process; 17 changes from 0 to 1 indicating an apomorphic deep notch between the two processes of the epiproct; and 18 changes to an apomorphic narrow lower process. In using the branch rearrangement facility in MacClade 4.08a ( Maddison and Maddison 2005), two most parsimonious trees result, both of which clearly move C. shasta into the C. ventura Subgroup and require little change to the Nelson and Baumann (2009) hypothesis of relationships. One places C. shasta basal to all members of the subgroup (from C. regilla to C. ventura in Fig. 10 of Nelson and Baumann (2009)) and the other places this taxon further up the tree between C. regilla and C. saratoga . Analysis using new information we present here resolved the tree to a more basal polytomy and by consensus created a polytomy further up the tree, within the C. ventura Subgroup. Resolution of this polytomy will require using additional morphological or molecular characters.

Distribution. The most recent collections of C. shasta were made in small creeks that the authors predict have reduced surface flow in the summer. This species is now known from three localities in the Coast Ranges of northern California, two near Castle Crags and one in the Salmon River drainage.

Figures

Figs. 1-8. Capnia shasta male genitalia. Figs. 1-4. California, Shasta County, creek near Castle Crags State Park. 1. Terminalia, dorsal. 2. Epiproct, dorsal. 3. Epiproct, dorsolateral. 4. Epiproct, lateral. Figs. 5-8. California, Siskiyou County, tributary, Salmon River, Salmon River Road. 5. Terminalia, dorsal. 6. Epiproct, dorsal. 7. Epiproct, dorsolateral. 8. Epiproct, dorsolateral, anterior.