Sweltsa occidens (Frison)

Kondratieff, Boris C. & Baumann, Richard W., 2009, A Contribution To The Knowledge Of Sweltsa Exquisita (Frison) And S. Occidens (Frison) And Description Of A New Species Of Sweltsa From The Northern Rocky Mountains, U. S. A. (Plecoptera: Chloroperlidae), Illiesia 5 (3), pp. 20-29 : 24-26

Sweltsa occidens (Frison)

( Figs. 10-17 )

Alloperla occidens Frison 1937: 96 . Holotype ♂, Illinois Natural History Survey: Razorhone Creek , Shucksan (sic) [Shuksan](Whatcom Co.), Washington.

Material examined. USA: Alaska: Pullen Creek, Skagway , 14 July 2002, K.T. Huntzinger, 1 ♂ ( BYUC) . Oregon: Clackamas Co., Mt. Hood , 3 mi below Timberline Lodge, 12 July 1979, B.P. Stark and K.W. Stewart, 1 ♀ ( BPSC) . Washington: Chelan Co. Minotaur Creek , 10 mi. W Wenatchee Lake, 14 July 1976, J.R. Wood, 7 ♂, 8 ♀ ( BYUC) ; 21 July 1976, 2 ♂, 3 ♀ ( BYUC) ; 4 August 1976, 3 ♂, 5 ♀ ( BYUC) ; Lewis Co., Laughingwater Creek , 27 June 1995, E. Lisowski, 5 ♂ ( CSUC) ; Falls Creek, Stevens Canyon Road , 25 June 2000, R. Lechleitner, 1 ♂ ( CSUC) ; Panther Creek , 9 June 2001, R. Lechleitner, 1 ♂ ( CSUC) ; Pierce Co., Paradise River, Fourth Crossing , Valley Road. , 16 August 1999, B. Kondratieff, 1 ♂ ( CSUC) ; 23 July 2000, R. Lechleitner, 2 ♂, 1 ♀ ( CSUC) ; Meadow Creek, Mt. Rainier National Park , 14 July 1979, B.P. Stark and K.W. Stewart, 1 ♂ ( BPSC) ; St. Andrews Creek, Westside Road , 24 July 1997, R. Lechleitner, 7 ♂, 25 ♀ ( BYUC, CSUC) ; Skamania Co, small creek, N Twin Fall Creek , 30 July 1983, G.R. Fiala, 1 ♀ ( BYUC) ; Snohomish Co., Crystal Creek , 1.6 mi. up FR 27 off FR 23, 11 mi. SE Darrington, 9 June 1994, G. Mackenzie, 1 ♂, 1 ♀ ( BYUC) ; Whatcom Co., Big Face Creek, E Ross Lake , 1 mi. SE of Joker Mountain, 8 August 1966, K.E. Vander Mey, 3 ♂, 12 ♀ ( BYUC) ; Swamp Creek , 7 August 1966, K.E. Vander Mey, 1 ♂, 1 ♀ ( BYUC) .

Male. General color yellow in life, head with dark ocellar rings, pronotum yellow, but with dark lateral margins, black stripe running down terga 1-8, terminal mark on tergum 8 longer than wide and never divided. Tergum 9 lacking bare elevated process ( Fig. 10 ). Epiproct erectile, elongate, in dorsal view, tapered to apex ( Fig. 10 ); extreme apex bare, ( Figs. 10-13 ), in lateral aspect, apex expanded ventrally, but generally flattened laterally ( Figs. 12 & 13 ); dorsal and lateral surface of epiproct covered with dense pile of long appressed setae, extending to the epiproct base ( Figs. 10-13 ), laterally, base bare ( Fig. 12 ). Aedeagus tubular, constricted near upper ⅓, with two bulbous lobes, bearing two smaller apical projections ( Figs. 14 & 15 ), more expanded apex with broad lobes and dorsal finger-like projection medially ( Fig. 16 ), surface with comb-like setae arranged in interrupted rows, with patch of stronger setae located at base of constricted area ( Figs. 16 & 17 ).

Female. Color and markings similar to male. Subgenital plate subtriangular and not covering all of sternum 9, apex more narrowly rounded, often exhibiting a shallow emarginate area at the tip, but the posterior margin is usually entire ( Fig. 27 ) for S. durfeei .

Figures

Figs. 10-17. Sweltsa occidens, male terminalia and aedeagus. 10. male terminalia, dorsal, St. Andrews Creek, Washington; 11. epiproct apex, dorsal, St. Andrews Creek, Washington; 12. epiproct, lateral, St. Andrews Creek, Washington; 13. epiproct apex, lateral, St. Andrews Creek, Washington; 14. aedeagus and epiproct, lateral, St. Andrews Creek, Washington; 15. aedeagus, terminal, St. Andrews Creek, Washington; 16. aedeagus, apex expanded, dorsal, Big Face Creek, Washington; 17. spine patch, aedeagus, dorsal, below apex, Big Face Creek, Washington.

Figs. 26-27. Female subgenital plate, ventral. 26. Sweltsa equisita, Fryingpan Creek, Washington; 27. Sweltsa durfeei, Van Ness Creek, Montana.