Larvae Of Five Species Of The Winter Stonefly Genus Capnia (Plecoptera: Capniidae) From California, U. S. A. Author Stewart, Kenneth W. Department of Biological Sciences, P. O. Box 305220, University of North Texas, Denton, Texas 76203, U. S. A. E-mail: stewart @ unt. edu stewart@unt.edu Author Drake, Eugene F. Entomology Research Museum, University of California, Riverside, California 95222, U. S. A. E-mail: edrake @ ucr. edu edrake@ucr.edu Author Stark, Bill P. Department of Biology, Box 4045, Mississippi College, Clinton, Mississippi 39058, U. S. A. E-mail: stark @ mc. edu stark@mc.edu text Illiesia 2011 7 18 167 181 journal article 6849 10.5281/zenodo.4760235 a69800a0-bc3f-49fe-a5e0-441d0b142e53 1854-0392 4760235 Capnia umpqua Frison 1942 ( Figs. 10, 11 , 20-25 , 44-49 , 56-59 ) Distribution. California and Oregon . Material examined. California : Orange Co. , Trabuko Creek , Trabuko Canyon , 1 st concrete low water crossing, N 33 ° 40.29 ’ W 117 ° 32.45 ’ , 5-IV-2005 , K.W. Stewart and E.F. Drake , 8♂ , 58♀ , 1♂ reared with exuvium, 2♂ larvae, 1♀ larva. Same locality, 25-IV- 2005 , E.F. Drake , 6♀ . No other Capnia species collected at this locality . Characters. Body length ♂ 5.0-6.0mm. Light to medium brown dorsally, ventrum lighter, little pattern except underlying muscles or developing adult pigment ( Figs. 20, 23 ). Antennal segments 46- 48, head capsule width ♂ 0.75mm , ♀ 0.96mm . Lacinia triangular, palmate with longitudinally striate palm surface, broad apical teeth, ventral comb of 10-14 bristles and dorsal comb of 16-18 longer bristles ( Fig. 44 ). Right mandible with apical teeth, molar pad of dense, stiff bristles, and inner band of hairs from base of apical teeth to molar pad ( Figs. 45, 46 ). Left mandible with molar cup bordered by outer (dorsal) comb of curved teeth ( Figs. 47, 48 ). Pronotum with scattered setae over surface and as a marginal fringe ( Fig. 20 ). Mesosternal Y-arms with enclosed subtriangular area about 0.3 times the intercostal width ( Fig. 22 ). Hind wingpads shallowly notched along inner margin ( Fig. 20 ); inside forewingpad length ♂ 0.96mm , ♀ 1.08mm . Femora with scattered surface bristles, and tibia with a silky outer fringe ( Fig. 21 ). Abdominal segments with long surface hairs ( Fig. 56 ). Sexual dimorphism evident. Males with short posterior extension of 10 th tergum, triangular in dorsal and ventral views ( Figs. 11 , 23 ) with underlying developing narrow, tubular epiproct visible in pharate individuals ( Figs. 11 , 23 ); 10 th tergum in lateral view subtriangular, nearly straight dorsally, with slightly downturned tip ( Figs. 10 , 49 ). Female without posterior extension of 10 th tergum ( Fig. 20 ). Cercal segments 28-30; cercomeres with apical circlet of short and long bristles, longer dorsal and ventral bristle in lateral view, and no intercalary hairs ( Figs. 24, 25 , 58, 59 ).