Fig. 6:43. 

 d,f, fu/va; o, 

 male (a,e, N 

 d,f, Claassen, 



Terminalia 

 b,f, ventral 



eedham and 



1937a). 



of / soper/a, o, e, ebria; b, c, patricia; 



view of female; c,d,e, dorsal view of 



Claassen, 1925; b,c, Frison, 1942b; 



Fig. 6:44. a, Kathroperla perdita, ventral view of female 

 terminalia; b, Paraperla frontalis, lateral view of male terminalia; 

 c, K. perdita, dorsolateral view of male terminalia (Needham and 

 Claassen, 1925). 



177 



Jewett: Plecoptera 



Family CHLO ROP E RL IDAE 



These stonoflies are Holarctic in distribution and 

 include two subfamilies, the Nearctic Parapcrlinae 

 and the Holarctic Chloroperlinae. The Paraperlinae 

 contain three monotypic genera, two of which occur 

 in California: Kathroperla Banks 1920, species perdita 

 Banks 1920 (figs. 6:96; 6:44a,c); and Paraperla Banks 

 1906, species frontalis (Banks) 1902 (figs. 6:446; 

 6:456). The recently described Vtaperla is recorded 

 from Yukon Territory and Utah (Ricker, 1952, p. 176). 

 The Chloroperlinae contains many North American 

 species which are placed in three genera. Chloroperla 

 Newman 1836 is represented in North America by the 

 subgenus Rasvena Ricker 1952 which contains a 

 single species found in the eastern United States. 

 Hastaperla Ricker 1935 is represented by three spe- 

 cies, one of which, //. chilnualna Ricker 1952, is 

 known from California. Another widespread species, 

 H. brevis (Banks) 1895, may occur in the state but 

 positive records are lacking. It differs in the male 

 from H. chilnualna principally in that the supra-anal 

 process in lateral view is not hooked and is broader 

 in dorsal view. About forty species of Alloperla 

 Banks 1906 in five subgenera occur in North America. 

 The following key separates the subgenera, and keys 

 the males of species known to occur in California. 

 The nymphs of Alloperla resemble one another very 

 closely and few have been described. 



Key to the North American Subgenera and 



California Species of Alloperla 15 



Males 



1. Basal segment of the cerci greatly elongated, deeply 

 concave inward, with a sharp spine inside near the 

 base and with 4 blunt knobs on the inside toward the 

 tip; 9th tergite with its hind border produced backward, 

 from which comes a stout forward-pointing decurved 

 hook; 10th tergite with erect processes from the hind 

 margin pointing upward and inward; (figs. 6:476; ?, 



6:50a); Alberta, British Columbia, and Washington . . 



(sub- 

 genus Neaviperla Ricker 1943) forcipata Neave 1929 



— Cerci normal; 9th tergfte without a median forward- 

 projecting hook; 10th tergite without dorsal processes 

 on the hind margin 2 



2. A fingerlike process pointing inward from the basal 

 segment of each cercus; supra-anal body a membranous 

 lobe with a very small hairy process at its tip (figs. 

 6:48c?; ?, 6:51A); British Columbia to California and 

 Alberta to Wyoming. . .(synonym: A. dubia Frison 1935) 



(sub- 

 genus Suwallia Ricker 1942) pallidula (Banks) 1904 



— No process at the base of the cercus; supra-anal body 

 elongate, its terminal process usually larger 3 



3. Color usually green in life; no dark abdominal stripe; 

 no process on the 9th tergite; 



(subgenus Alloperla, s.s. Banks 1906) 4 



— Color mostly yellow in life; a dark dorsal stripe present 

 on the abdomen; with or without a process on the 9th 

 tergite 6 



4. Process at the tip of the supra-anal body dumbbell- 

 shaped, longer than broad, rounded in front and behind 



5 



— Process at the tip of the supra-anal body short, its 



"Adapted in part from Ricker (1943, 1952). 



