August. 1944 



Ross: Caddis Flies of Illinois 



141 



nois. In our recent collecting we have taken 

 the species at various points in the north- 

 eastern part of the state and found the 

 larvae frequenting ponds and lakes. Adult 

 records extend from June 9 to August 15, 

 probably indicating more than one genera- 

 tion per year. 



Although collections are not common, the 

 range of the species is wide, as shown by 

 records from the District of Columbia, Illi- 

 nois, Kentucky, Maryland, Minnesota, New 

 York, Texas, Virginia. 



Illinois Records. — Antioch : Aug. 1, 



1931, Prison, Betten & Ross, 1$ ; July 7, 



1932, at light in town. Prison & Metcalf, 

 2$, 15. Fox Lake: June 30, 1935, De- 

 Long & Ross, I $ , 1 ? . Palos Park, Mud 

 Lake: Aug. 3, 1938, Ross & Burks, $ S, 

 $ ?. Richmond: Aug. 15, 1938, Ross & 

 Burks, 5 9 . RoSECRANS, Des Plaines River: 

 June 19, 1938, Ross & Burks, 2$. Spring 

 Grove: Aug. 12, 1937, at light, Ross & 

 Burks, 3$, 3 5; June 9, 1938, Mohr & 

 Burks, 6$ , 65. 



Orthotrichia cristata Morton 



Orthotrichia cristata Morton (1905, p. 73); cf . 



Larva. — Not differentiated from ameri- 

 cana. 



Adults. — Size and color as for americana. 

 Seventh sternite with a mesal process bear- 

 ing a large brush of long scales. Male 

 genitalia, fig. 500: similar in general organ- 

 ization to americana; claspers larger, black 

 and produced into lateral processes; process 

 above, small, quadrate, with two small api- 

 cal spines; no large, curved blade present. 

 Female genitalia, fig. 502, with only a small, 

 membranous mesal area. 



Allotype, female. — Belton, Montana: 

 July 10, 1940, at light, H. H. & J. A. Ross. 



In Illinois we have taken this species in 

 fewer numbers but in more widespread lo- 

 calities than americana, including localities 

 along small streams, lakes and ponds. Adult 

 emergence continues from June to August. 



The range of the species is widespread, 

 with records from British Columbia, Illi- 

 nois, Michigan, Montana, Oklahoma, Ten- 

 nessee, Texas. 



Illinois Records. — ^Antioch: at light in 

 town, July 7, 1932, Prison & Metcalf, 1 5 . 

 Pox Lake: June 30, 1935, DeLong & Ross, 

 15,25. Oakwood, Salt Fork River: July 

 18, 1933, Ross & Mohr, 1 5. Palos Park, 

 Mud Lake: Aug. 3, 1938, Ross & Burks, 



15,25. Spring Grove: at light, Aug. 12, 

 1937, Ross & Burks, 5^,55; June 9, 1938, 

 Mohr & Burks, 6$, 65. White Pines 

 Forest State Park: Aug. 13, 1937, Ross 

 & Burks, 1 (5 . 



Hydroptila D aim an 



Hydroptila Daiman (1819, p. 125). Geno- 

 type, monobasic; Hydroptila tineoides Daiman. 



Phrixocoma Eaton (1873, p. 132). Genotype, 

 here designated: Hydroptila spars a Curtis. 



This genus embraces about 35 Nearctic 

 species, comprising one-third of the Hydrop- 

 tilidae. The habits of the various species 

 are diverse. Several species have a known 

 range covering most of the continent. Four- 

 teen species have been taken in Illinois, nine 

 of which we have reared. No structural dif- 

 ferences have been found to separate the 

 larvae to species, so that color has been the 

 only guide to separation. This varies so 

 much in some species, and is so similar in 

 other species, that it seems impossible at 

 present to make a key which would be accu- 

 rate. Instead, a short diagnosis is presented 

 drawing attention to the few characters so 

 far discovered. 



DIAGNOSIS OF LARVAE 



1. Head yellowish or brown, without defi- 

 nite markings — paler specimens are usually 

 ajax, darker specimens usually angusta, and 

 nearly black specimens consimilis, fig. 503. 



2. Head and pronotum pale yellow with 

 scattered, small, dark spots as in fig. 504: 

 spatulata. 



3. Head and thoracic sclerites with a 

 contrasting pattern as in fig. 505, the head 

 always with a light, postero-mesal streak, the 

 nota always with a pair of lateral, light areas: 

 albicornis. 



4. Head yellow, marked only with a pair 

 of posterior dark bars, and each thoracic 

 notum with a transverse dark bar in addition 

 to dark posterior margin, fig. 506: armata. 



5. Head entirely yellow except for a wide, 

 black V across top of frons, fig. 507; pronotum 

 variable in color: hamata. In darker speci- 

 mens the posterior portion of the head is 

 darker and the black V-mark enlarges an- 

 teriorly to a pentagon. 



6. Head yellowish, with both a wide 

 posterior dark band and a V-shaped dark 

 mark above frons, fig. 508; each thoracic 

 notum with anterior portion and two vague 

 lateral areas pale, intervening areas brownish: 

 grandiosa. In darker specimens the V-mark 

 enlarges to form a hollow diamond. 



