Capnia umpqua Frison 1942

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).