August, 1944 



Ross: Caddis Flies of Illinois 



131 



center area covered with small, sharp spic- 

 ules; tenth tergite similar to that in fig. 

 480, long, somewhat triangular, rounded at 

 apex, the cerci arising from the lateral mar- 

 gin. 



Allotype, female. — HoUister, Missouri: 

 July 14, 1938, Mrs. Vitae Kite. 



The male genitalia extremely distinctive, 

 resembling only those of stylata, fig. 472, 

 which may be distinguished by the large, 

 dark basal process of the tenth tergite. This 

 latter species is apparently western in range 

 (Montana to Oklahoma). 



Showing a preference for clear, medium- 

 sized streams, tarsalis occurs in several such 

 streams in Illinois. We have established the 

 identity of the larvae by collections of pupae 

 from the Salt Fork River at Oakwood. 



The range of tarsalis is widespread and 

 includes Illinois, Indiana, Missouri, New 

 York, Oklahoma, Ontario, Texas and Wis- 

 consin. 



Illinois Records. — Danville, Middle 

 Fork River: Aug. 27, 1936, Ross & Burks, 

 \S, 1$, many larvae. Kankakee: Aug. 

 1, 1933, Ross & Mohr, 1 $ ; July 21, 1935, 

 Ross & Mohr, 2 $ . Mahomet, Sangamon 

 River: June 6, 1940, Ross & Riegel, many 

 larvae. Momence: Aug. 21, 1936, Ross 

 & Burks, 8<? ; Kankakee River, May 26, 

 1936, H. H. Ross, 2 larvae; May 17, 1937, 

 Ross & Burks, many larvae; June 22, 1938, 

 Ross & Burks, 2 <? ; June 6, 1940, Ross & 

 Riegel, many larvae. Morris: Aug. 22, 

 1938, H. H. Ross, 1 9 . Oakwood, Salt Fork 

 River: July 18, 1933, Ross k Mohr, 1 <? . 

 Ottawa: July 3, 1937, at light, Werner, 

 19. White Pines Forest State Park: 

 Aug. 13, 1937, Ross & Burks, 1$. Wil- 

 mington: July 1, 1935, DeLong & Ross, 



u. 



Ochrotrichia anisca (Ross) 



Polytrichia anisca Ross {\9A\b, p. 58); cf, 

 9. 



Larva. — Length 4 mm. Head, thoracic 

 sclerites, and legs light brownish yellow, 

 frequently with a faint reddish tone; some- 

 times indistinct suffusions of a darker color 

 are present but never forming distinct mark- 

 ings as in tarsalis. Abdominal tergites with 

 only inconspicuous sclerotized rings. Case 

 purselike. 



Adults. — Size and color as for unio. 

 Male genitalia with ninth segment and 

 claspers similar to shaivnee, fig. 468; tenth 



tergite, fig. 470, with process, C, stout, 

 curved mesad and then abruptly laterad; 

 D, short and stout, situated more than its 

 own length from spiral, S ; the hook, F, 

 longer and close to the spiral. Female geni- 

 talia, fig. 480: eighth sternite with apical 

 margin slightly reticulate but not produced; 

 internal rods markedly sinuate, following 

 the shape of the membranous, indistinct en- 

 doskeleton. Tenth tergite somewhat trian- 

 gular, the apex rounded, and the cerci aris- 

 ing from the lateral margin. 



In Illinois this species frequents several 

 small temporary streams in the Ozarkian 

 region. These streams are rapid and clear 

 in early spring when the larvae of the spe- 

 cies mature. Collections of pupae at Wolf 

 Lake have associated the larval and adult 

 stages. A very large colony of larvae at this 

 locality was unique in that each case had a 

 comparatively large "anchor" stone attached 

 to one side. 



The range of the species extends through 

 the Ozarks and neighboring mountains, with 

 records for Arkansas, Illinois and Okla- 

 homa. 



Illinois Records. — LaRue, McCann 

 School: May 26, 1939, Burks & Riegel. 

 $ $, 9 9. Wolf Lake: Hutchins Creek, 

 May 25, 1940, Mohr & Burks, many larvae; 

 May 31, 1940, B. D. Burks, $ $, 9 9. 



Ochrotrichia contorta (Ross) 



Polytrichia contorta Ross (1941^, p. 60); cf . 



This species is known from various locali- 

 ties in south central Missouri in the Ozarks 

 and might be collected in Illinois. 



Ochrotrichia shawnee (Ross) 



Polytrichia shawnee Ross (1938^, p. 120); 

 cf , 9o 



Larva. — Unknown. 



Adults. — Size and color as for unio. 

 Male genitalia, fig. 468: ninth segment 

 short, claspers shoe shaped, both appearing 

 long, slender and similar in shape from ven- 

 tral view; tenth tergite divided into many 

 parts; the right sclerite, 5, formed near 

 apex into a coiled spring, 5, and beyond 

 that forming a bent point, /"; left process, 

 //, with a long, slender style, C, arising 

 near base, beyond this a mesal process, D, 

 which has a sclerotized, narrow, pointed tip 



