248 



Denning: Trichoptera 



curved (fig. 10:15^); Shasta to Santa Cruz counties. 

 novuaamericanus (Ling) 1938 



— Apical segment of clasper not much narrower than 

 basal segment 2 



2. Tenth tergite with lateral portions widely separated 

 on meson (fig. 10: 15c); Del Norte County 



dor'cus (Ross) 1938 



— Tenth tergite with lateral portions confluent most of 

 the distance 3 



3. Cerci, in dorsal aspect, long, slender; apex of 10th 

 tergite subacute, slightly overlapping, slightly ex- 

 ceeding cerci (fig. 10:l5e); Tuolumne County 



pallidipes (Banks) 1936 



— Cerci, in dorsal aspect, somewhat orbicular; apex of 

 10th tergite blunt, divergent, greatly exceeding cerci 

 (fig. 10:15/); Placer to San Bernardino counties. . . . 



aequalis (Banks) 1924 



Genus Chimarra Stephens 1829 



Only two of the thirteen Nearctic species of Chimarra 

 are known to occur in California. It is possible that 

 angustipennis Banks and elia Ross eventually will 

 be collected here. 



The adults are generally small, 6 to 8 mm. in 

 length, dark brown to black in color, and are very 

 secretive. The quick flying adults are usually found 

 in humid areas alongside streams. 



The larvae are found in rapid and clear streams, 

 and one species, feria Ross, has been found in 

 streams which become dry in the summer and fall. 

 Larvae of our western species are unknown. 



Key to Adult Males 



Apicodorsal margin of clasper with no mesal projec- 

 tion (fig. 10:15y); Humboldt County to Yolo County . . . 



siva Denning 1949 



Apicodorsal margin of clasper with a distinct mesal 

 projection (fig. 10:166); Shasta County to Santa Barbara 

 County utahensis (Ross) 1938 



Genus Wormaldia McLachlan 1865 



Seven of the thirteen Nearctic species have been 

 taken in California. The larvae are associated with 

 clear, rapid streams. The adults, about 7 to 12 mm. 

 in length, are usually dark brown to black. 



Key to Adult Males 5 



1 . Tergum of 8th segment normal 2 



— Tergum of 8th segment elongated, extended dorso- 

 caudad beyond 9th segment (fig. 10:16J); Trinity 

 County hamata Denning 1951 



2. Seventh sternite with a long, narrow mesal process; 

 8th sternite with a short process or none (fig. 10:16c); 

 Siskiyou County to Los Angeles County 



gabriella Banks 1930 



— Seventh sternite with a short triangular process or 

 none 3 



3. Clasper elongate and slender 4 



— Clasper short and stout 5 



4. Clasper with apical segment slender and shorter than 



'Adapted from Ross (1944). 



h h2 



Fig. 10:16. Male genitalia, a, Wormaldia anil la, lateral; b, 

 Chimmara utahensis, lateral; b u ninth and tenth segments, dorsal; 

 c, Wormaldia gabriella, lateral; d, W. hamaia, lateral; e. W. 

 cruzensis, lateral; e u tenth tergite, dorsal; f, Polycentropus 

 flaws, lateral; g, Wormaldia occidea, lateral; g,, ventral view; h, 

 Wormaldia sisko, lateral; h 1 , tenth tergite; h 2 , process of sixth 

 sternite (a, Ross, 1941b; b,g, Ross r 1938a; c,e. Ling, 1938, 

 unpublished figs.; d, Denning, 1951; f, Ross, 1944; h, Ross, 

 1949b). 



basal segment (fig. 10:16A); Tulare County 



sisko Ross 1 949 



— Clasper with apical segment considerably longer than 

 basal segment (fig. 10:37); Nevada County 



pachita Denning 1955 



5. Seventh sternite with a triangular apicomesal process; 

 apical segment of clasper shorter than basal segment 

 (fig. 10:16^); Glenn County occidea (Ross) 1938 



— Seventh sternite without a triangular apicomesal 

 process 5 



6. Apical segment of clasper parallel-sided (fig. 10:16e); 

 Santa Cruz County cruzensis (Ling) 1938 



— Apical segment of clasper markedly constricted (fig. 

 10: 16a); Shasta County anilla (Ross) 1941 



Family PSYCHOMYIIDAE 



This is a large family of world-wide distribution and 

 contains nine Nearctic genera with sixty-two species. 

 Some of the species are Holarctic or transcontinental 

 in range and are locally very abundant. The larvae 

 spin a long silken net and are found in water varying 



