176 



Jewett: Plecoptera 



Fig. 6:41. Call iperla luctuosa, terminalia. a, ventral view 

 of female; b, lateral view of male (Needham and Claassen, 

 1925). 



— Tip of male 10th tergite without process; male 8th 

 sternite with a lobe (obsolescent in ebria); female 8th 

 sternite not as above; color not as above 2 



2. Lobe at the tip of the male 8th sternite nearly square 

 with subacute angles; spinules present on the male 

 9th tergite (fig. 6:42c); female subgenital plate very 

 little produced (fig. 6:42d); a small yellowish species; 

 British Columbia to California and Montana to Wyoming 



and Arizona 



(synonym: /. insipida Hoppe 1938) mormona Banks 1920 



— Lobe on the male 8th sternite broadly rounded behind; 

 male 9th tergite without spinules, though with short 

 stout hairs in patricia; female subgenital plates vary; 

 medium to large species 3 



3. Pronotum with a checkered pattern of black on yellow; 

 female subgenital plate moderately produced, slightly 

 excavated at the middle (fig. 6:42c); male subanal lobes 

 flat, recurved, acute, bent outward near the tips (fig. 

 6:42/); British Columbia to California and Wyoming 

 pinta Frison 1937 



— Pronotum striped or reticulately marked; female sub- 

 genital plates varied; male subanal lobes not bent 

 outward close to their tips 4 



4. Female subgenital plate long, its sides parallel or 

 nearly so near the base (fig. 6:43a); hind margin of the 

 male 8th sternite with a hairless yellow area, but 

 scarcely a lobe (fig. 6:43c); head with a sharp pattern 

 of brown or yellow, including an ocellar and a pre- 

 ocellar yellow spot; British Columbia to California 



ebria (Hagen) 1875 



— Female subgenital plate shorter, usually its sides 

 turned inward making an angle of at least 135° with the 

 side margin of the segment; male with a definite lobe 

 on the 8th sternite 5 



5. Female subgenital plate only slightly produced (fig. 

 6:42<7); male subanal lobes acutely bent upward, long, 

 thin, pointed (fig. 6:42A); Washington to California 



sordida (Banks) 1906 



— Female subgenital plate distinctly produced; male sub- 

 anal lobes not long, thin, and acutely bent 6 



6. Subgenital plate of female with a wide, deep excavation 

 at the tip (fig. 6:436); male with patches of short stout 

 hairs on the posterior margin of the 9th tergite (fig. 

 6:43c); a yellowish species; British Columbia to Cali- 

 fornia; South Dakota to Colorado 



patricia Frison 1942 u 



— Subgenital plate of female without a median excavation; 

 male without patches of short stout hairs on the poster- 



/. S-punctala (Banks) 1902, recorded for California by Need- 

 ham and Claassen (1925, p. 152) and Seemann (1927, p. 57) 

 may key here; it is said to have greenish wings. 



i 6:42. Terminalia of Isoperla. a, trictura, lateral view of 

 b, trictura, ventral view of female; c, mormona, ventral 

 view of male; d, mormona, ventral view of female; e, pinta, 

 ventral view of female; i, pinta, dorsal view of male; g, sordida, 

 ventral view of female; h, sordida, dorsal view of male (a,b t 

 Frison, 1942b; c,d,g,h, Needham and Claassen, 1925; e,f, Frison, 

 1937). 



ior margin of the 9th tergite 7 



7. Anal area of wings not infuscated; subgenital plate of 

 female broadly rounded, thickened and rather suddenly 

 bent downward near tip (fig. 6:43/); head pattern inter- 

 rupted at the transverse occipital suture; subanal lobes 

 of male stout, tips abruptly pointed (fig. 6:43cf); British 

 Columbia to California. . .(synonyms: chrysannula and 



cascadensis Hoppe 1938) fulva Claassen 1937 



— Anal area of wings distinctly infuscated; female sub- 

 genital plate slightly produced, not bent abruptly 

 downward; head pattern not interrupted at the transverse 

 occipital suture; subanal lobes of male gradually taper- 

 ing to sharp points; California and Oregon (fig. 6:53c) 

 marmorata (Needham and Claassen) 1925 



