August, 1944 



Ross: Caddis Flies of Illinois 



137 



Fig. 498. — Oxyethira serrata, case. 



of the year, from May to the middle of 

 July; the number of generations per year 

 has not been determined. In local areas 

 around these lakes the species sometimes 

 occurs in tremendous numbers, swarming 

 around lights. 



Little is known concerning the range of 

 the species, with records available only from 

 Illinois, New York and Wisconsin. All 

 records, however, indicate a restriction to 

 lakes and connecting channels. 



Illinois Records. — Antioch : July 7, 

 1932, Prison & Metcalf, A$, 9 ?. Chan- 

 nel Lake: May 27, 1936, H. H. Ross, 

 $ $, 5$. Fox Lake: July 15, 1935, at 

 light in town, DeLong & Ross, $ $ , 5 5 ; 

 May 15, 1936, Ross & Mohr, $ $, 9 ?, 

 many pupae, 2 larvae; May 28, 1936, H. H. 

 Ross, $ $ , 1 $ ; June 10, 1936, Ross & 

 Burks, 1$. JoHNSBURG, Fox River: May 

 28, 1936, H. H. Ross, $ $ , ? $ . 



Oxyethira pallida (Banks) 



Ortholrichia pallida Banks (1904^, p. 215); 



&. 



Oxyethira viminalis Morton (1905, p. 71); 



Adults. — Length 3 mm. Color a salt- 

 and-pepper combination of cream and light 



brown, the general tone light. Male geni- 

 talia, fig. 486, with aedeagus split and curi- 

 ously twisted. Female genitalia, fig. 494: 

 eighth sternite produced into a wide, emar- 

 ginate lobe which is sclerotized along the 

 sides; tenth segment fairly long; ninth seg- 

 ment with very long and curved internal 

 rods which extend below and to the side of 

 the bursa copulatrix ; bursa copulatrix short, 

 with a ventral sclerotized bridge. 



Allotype, female, — Wilmington, Illinois: 

 Aug. 20, 1934, DeLong & Ross. 



This species was first recorded from Illi- 

 nois in the original description of viminalis, 

 in which Morton recorded material from 

 Lake Forest, collected October 15, 1902, by 

 Professor Needham. We have since taken 

 it in scattered localities in the northern 

 half of the state. Adult emergence occurs 

 throughout the warmer months of the year, 

 from June to October. Our records indi- 

 cate that the species frequents streams, lakes 

 and artificial ponds. This is very likely the 

 species which has been taken in large num- 

 bers as larvae by various fish in certain 

 experimental lakes investigated by the Nat- 

 ural History Survey. 



The distribution of the species apparently 

 occupies most of the eastern and central part 

 of the continent, with records available for 

 the District of Columbia, Illinois, Nebraska, 

 New York, Oklahoma, Texas, Virginia and 

 Wisconsin. 



Illinois Records. — Council Hill, Ga- 

 lena River: June 26, 1940, Mohr & Riegel, 

 $ $ , 9 9. Downs, Kickapoo Creek: July 

 31, 1940, Ross & Riegel, 2$. Fox Lake: 

 Sept. 22, 1931, Frison & Ross, 2$ ; Oct. 4, 

 1931, Ross & Mohr, 1 $ . Kankakee: July 

 21, 1935, Ross & Mohr, 1^. Liverpool: 

 Oct. 7, 1931, T. H. Frison, 3 5, 99. Mc- 

 Henry: Oct. 4, 1931, Ross & Mohr, \$. 

 Momence: June 22, 1938, Ross & Burks, 

 \$. Palos Park, Mud Lake: Aug. 3, 

 1938, Ross & Burks, 99. Quincy, Burton 

 Creek: June 25, 1940, Mohr & Riegel, 1 9 . 

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

 & Burks, 9 9 . White Pines Forest State 

 Park: Aug. 13, 1937, Ross & Burks, $ $, 

 9 9. Wilmington: Aug. 20, 1934, De- 

 Long & Ross, 2 5,89. 



Oxyethira coercens Morton 



Oxyethira coercens Morton (1905, p. 70); cf . 



Adults. — Length 3 mm. Color a salt- 

 and-pepper mottling of cream and brown. 



