August, 1944 



Ross: Caddis Flies of Illinois 



173 



margin; posterior to this projection is a 

 fairly wide and long, heavily sclerotized 

 piece. 



This species has been collected at scattered 

 points in the central and northern portions 

 of Illinois. At Oakwood we reared it from 

 larvae collected in the back waters of a 

 small stream. At other localities we have 

 taken unreared larvae of this genus in sim- 

 ilar situations. Our adult records extend 

 from April to late June, indicating that we 

 may have only a single early summer emer- 

 gence of adults in Illinois. In more northern 

 states, the species emerges later. 



This species is widespread through the 

 Northeast; records are known from Illinois, 

 Indiana, Michigan, New Jersey, New York, 

 Nova Scotia, Ohio, Ontario, Pennsylvania, 

 Quebec and Wisconsin. 



Illinois Records. — Algonquin: June 

 17, 1907, W. A. Nason, 1 ? ; June 16, 1908, 



1 9 ; June 29, 1909, at light, Nason, 2$ ; 

 June 20, 1910, at light, Nason, 3 $ . Chi- 

 cago: June 28, 1908, 19 ; June 4, W. J. 

 Gerhard, 1^, 15, fm. Harvard: Chas. 

 Faust, 1^. Havana: Chas. Faust, 1^. 

 Northern Illinois: 1 $ ; May, Peabody 

 Collection, 1^. Oakwood: April 10, 1936, 

 Ross & Mohr, 12, 2 larvae, 1 larva 

 (reared); May 27, 1936, Ross & Mohr, 



2 5,5$; June 1, 1936, Ross & Mohr, 1 9 ; 

 June 13, 1936, Ross & Mohr, 19. Palos 

 Park: June 20, 1908, W. J. Gerhard, 1 $ , 

 FM. Urbana: June 12, 1886, Hart, 1$. 



Ptilostomis semifasciata (Say) 



Phryganea semijasciata Say (1828, pi. 44). 

 Neuroniajusca Walker (1852, p. 9); c?'. 

 Neuronia dubitans Betten & Mosely (1940, 

 p. 105); 9. New synonymy. 



Adults. — In size and color similar to the 

 preceding species. Male genitalia, fig. 594: 

 tenth tergite, very complex, having a pair of 

 long, widely separated dorso-lateral append- 

 ages arising from extreme base, a pair of 

 setal tufts arising from central portion, and 

 with the lateral margins modified at apex 

 into a pair of sclerotized plates which end 

 in a long, narrow upturned blade; ninth 

 segment with apex of shelflike portion bear- 

 ing four teeth on the emarginate ventral 

 margin and an irregular group of teeth on 

 the dorsal margin. Female genitalia, fig. 

 598, with bursa copulatrix bearing a large, 

 long keel on the venter, this keel being the 

 most prominent part of the entire structure. 



Neotype, male. — Momence, Illinois: 

 June 4, 1932, Prison & Mohr. 



The traditional identification of this spe- 

 cies has been quite uniform for many years, 

 and in order to avoid any ambiguity I have 

 selected the above neotype since Say's type 

 is lost. 



This species, like the preceding, has been 

 taken at scattered localities in the northern 

 half of Illinois. Our adult records are en- 

 tirely from June and July, indicating a single 

 adult brood. Specimens have been taken in 

 the proximity of both lakes and streams, 

 with a preponderance of records from local- 

 ities near streams. 



The range of the species is apparently 

 widespread through the Northeast; records 

 are available from Illinois, Kentucky, Ohio, 

 Quebec, South Dakota and Wisconsin. 



Illinois Records. — Algonquin: June 

 10, 1905, W. A. Nason, 1 $ ; June 13, 1905, 

 W. A. Nason, 1 $ ; July 10, 1905, W. A. 

 Nason, 1 $ ; July 13, 1905, W. A. Nason, 

 1 $ ; June 13, 1910, W. A. Nason, 1 9 ; 

 June 20, 1910, at light, W. A. Nason, U. 

 Channel Lake: June 15, 1928, T. H. 

 Frison, 19. Charleston: June 11, 1931, 

 at light, H. H. Ross, 1 9 . Elgin, Botanical 

 Gardens: June 6, 1939, Burks & Riegel, 

 1 9 . Fithian: June 18, 1919, at light, 1 9 . 

 Homer: June 30, 1927, at light, Frison & 

 Glasgow, 19. Momence: June 4, 1932, 

 Frison & Mohr, \ $ , 19; 3 miles east, 

 June 22, 1938, Ross & Burks, 1 9 . Oregon: 

 June, 1930, Sauer, 19. Palos Park: July 

 2, 1910, W. J. Gerhard, 19, fm. Rich- 

 mond: June 4, 1938, Ross & Burks, 1^. 

 St. Joseph: July 30, 1929, T. H. Frison, 

 \$. Urbana: July 18, 1885, 19. Wads- 

 worth, Des Plaines River: July 7, 1937, 

 Frison & Ross, 1 9 . 



Ptilostomis postica (Walker) 



Neuronia postica Walker (1852, p. 9); 9. 



Adults. — Length 19-20 mm. Color as in 

 ocellifera. Male genitalia, fig. 595: tenth 

 tergite with central portion long and styli- 

 form, with two pairs of processes which 

 arise from it, then angle suddenly and run 

 parallel with the segment; the dorsal pair 

 is very long, the lateral pair short; apical 

 shelflike projection of ninth sternite with 

 a pair of ventral, low teeth and an arcuate 

 row of smaller, irregular teeth. Female 

 genitalia, fig. 599, with bursa copulatrix 

 having a long, ventral blade which bears 



