Capnia limata, Bvachyptera fosketti, and B. pacifica, emerged when the river 

 was still essentially covered with ice. Stoneflies are not as abundant as 

 mayflies and spend less time in flight; they are therefore less conspicuous 

 when emerging. The most spectacular stonefly emergence is that of Pteronarays 

 oalifoimioa, the giant stonefly or the "salmonfly" of fly fishermen. This 

 species is confined to the upper river where adult insect sampling was less 

 intense. A small yellow stonefly, Isoperla longiseta (figure 31) emerges in 

 large numbers in the lower river. 



Figure 31. Adult stonefly (Isoperla longiseta), 



CADDISFLIES 



The emergence patterns of caddisflies are presented in figure 32. Emergence 

 and flight times ranged from May to September. Caddisflies and stoneflies can 

 live for several weeks as adults; therefore, the presence of an adult does not 

 necessarily signify recent emergence. The list of species presented in figure 

 32 is much larger than either the mayfly or stonefly lists (figures 27 and 30) 

 because the fauna is rich and because adult caddisflies, readily attracted to 

 lights, are easily collected. 



50 



