August, 1944 



Ross: Caddis Flies of Illinois 



153 



and two pupae, taken May 1 to October 16, 

 and many larvae, taken August 1 to August 

 27, are from Amboy, Charleston, Danville, 

 Galena, Homer, Kankakee, Mahomet, Mi- 

 lan, Momence, Morris, Mount Carroll, 

 Muncie, Oakwood, Ottawa, Putnam, Rich- 

 mond, Rock City, Rock Island, Serena, 

 Spring Grove, Sugar Grove, Wilmington. 



Hydroptila consimilis Morton 



Hydroptila consimi/is Morton (1905, p. 65); 



Larva. — Fig. 503. Head and thoracic 

 nota mostly black; head sometimes with a 

 narrow pale area between posterior and 

 anterior dark areas; thoracic nota with an- 

 terior margin pale. 



Adults. — Male, fig. 523: similar in most 

 structures to the preceding species, but dif- 

 fering as follows: claspers wider, rounder 

 at apex ; the apex of the aedeagus robust 

 and shorter, with a long, finger-like, lateral 

 process at tip. Female, fig. 537: eighth seg- 

 ment semimembranous, tapering; tergite 

 with a wide, shallow incision at apex, the 

 bottom of the incision with a sclerotized, 

 mesal thickening; sternite with a somewhat 

 trapezoidal mesal ornament and a rounded, 

 mesal projection. 



Allotype, female. — Utica, Illinois, Split 

 Rock Brook: July 11, 1941, Ross & Ries. 



Although taken several times, this species 

 must be classed as a rarity in Illinois. We 

 have taken it in numbers only in two peculiar 

 and restricted situations, at Elgin and Split 

 Rock (Utica). Other records are from 

 clear, permanent streams, most of them in 

 the northern quarter of the state. All our 

 records are in June and July, but records 

 for other states indicate that the adults 

 emerge from April to September. 



The range of the species is extensive and 

 seems to cover all the mountainous and 

 much of the heavily wooded areas from 

 Texas to British Columbia in one direction 

 and New York in the other. Records are 

 available from Arizona, British Columbia, 

 Illinois, New York, Oklahoma, Oregon, 

 Tennessee, Texas, Utah, Virginia and Wy- 

 oming. 



Illinois Records. — Many males, females 

 and eight pupae taken June 5 to August 15, 

 and five larvae taken May 23 to June 6, 

 are from Apple River Canyon State Park, 

 Council Hill (Galena River), Dixon, Elgin 



(Rainbow Springs), Galena, Mount Car- 

 roll, Muncie, Oakwood (Middle Fork Ver- 

 milion River), Utica (Split Rock Brook), 

 White Pines Forest State Park. 



Hydroptila perdita Morton 



Hydroptila perdita Morton (1905, p. 67); cf. 



Larva. — Unknown. 



Adults. — Male, fig. 524: tenth tergite 

 large, somewhat hood shaped, almost entire- 

 ly membranous except for a mesal, clavate 

 sclerotized strip. Claspers with a distinct 

 foot, the blade long, slightly out-curved at 

 apex, and with a dark, sclerotized point at 

 each apical angle. Aedeagus with a stout 

 spiral and with the tip of the apical portion 

 bent to form a sharp, right-angled process. 

 Female, fig. 534: eighth segment wide at 

 base and semimembranous; tergite with 

 sloping apex and a narrow mesal incision; 

 sternite with sinuate apical margin and a 

 wide, rounded incision; near the center of 

 the sternite is a bell-shaped plate. 



Allotype, female. — Washington County, 

 Arkansas: June 19, 1940, M. W. Sander- 

 son. 



To date we have only two records of this 

 species for Illinois, from the Kankakee and 

 Salt Fork rivers, both on the extreme east- 

 ern edge of the state. These, together with 

 other localities, indicate a preference for 

 large, clear, rapid streams, with adult emer- 

 gence from May to October. 



Available records are from Arkansas, Illi- 

 nois, Michigan, New York, Ontario and 

 Pennsylvania. 



Illinois Records. — Momence, Kankakee 

 River: May 24, 1937, H. H. Ross, \$. 

 Oakwood, Salt Fork River: July 18, 1933, 

 Ross & Mohr, 1$. Spring Grove: Aug. 

 12, 1937, at light, Ross & Burks, 3,?. 



Hydroptila ajax Ross 



Hydroptila ajax Ross (1938^, p. 127); cf, 9. 



Larva. — Head and thoracic sclerites taw- 

 ny yellow, varying somewhat in exact shade 

 but not forming a pattern. 



Adults. — Size and color as for armata. 

 Male genitalia, fig. 525: tenth tergite hood- 

 like, divided by membranous darts into a 

 mesal and pair of lateral lobes; claspers 

 having a distinct foot and a fairly long, nar- 

 row blade with the apex outcurved and a 

 sclerotized point on each apical corner ; 



