August, 1944 



Ross: Caddis Flies of Illinois 



251 



only in the glacial lakes in the northeast 

 part of the state. In these the larvae were 

 taken in large numbers from weed beds and 

 were reared from these collections. Our 

 adult collections extend from May to 

 late September, indicating that more than 

 one generation may be produced in a year. 



Female genitalia, fig. 860, similar in general 

 structure to tarsia but differing in the scle- 

 rotized, flared and convoluted ventro-lateral 

 expansions of the ninth segment. 



This species is a rarity in our Illinois 

 collections; our records to date consist of 

 only two males, from Chicago and Mo- 



Fig. 863. — Triaenodes tar-da cf 



This species is widely distributed through 

 the northeastern states and extends south- 

 westward through the Ozarks into Okla- 

 homa, with records from Arkansas, District 

 of Columbia, Illinois, Minnesota, New 

 Brunswick, New York, Ohio, Oklahoma, 

 Ontario, Pennsylvania and Wisconsin. In 

 addition, Milne lists the species from Ari- 

 zona and British Columbia (paratypes of 

 tarda) . 



Illinois Records. — Many males and fe- 

 males, taken May 31 to September 25, and 

 many larvae, taken May 15 to August 13, 

 are from Algonquin, Antioch, Champaign, 

 Chicago, Elgin (Botanical Gardens), Fox 

 Lake, Havana (Quiver Lake), New Mem- 

 phis (Kaskaskia River), Richmond, Sand 

 Lake, Spring Grove (Nippersink Creek), 

 Urbana, Zion (Dunes Park). 



Triaenodes tnarginata Sibley 



Triaenodes marginata Siblev (1926rt, p. 80); 



Larva (after Sibley, 1926^, p. 105).— 

 Head and pronotum yellow; head with two 

 pairs of dark lines and scattered spots; 

 pronotum with only small dark markings 

 on a pale background. 



Adults. — Length 12-13 mm. Color taw- 

 ny with a black and cream pattern as shown 

 in fig. 863. Male genitalia, fig. 850, simi- 

 lar in general structure to tarda, differing 

 chiefly in the spatulate tenth tergite and 

 long lateral projections of the claspers, these 

 processes curved sharply mesad at apex. 



mence, both in the northeastern portion of 

 the state. 



The species has a wide range, including 

 Arkansas, Illinois, Michigan, New Jersey, 

 New York, Nova Scotia and South Dakota. 



Illinois Records. — Chicago: Roof of 

 Stevens Hotel, July 13, 1931, T. H. Frison, 

 1^. Momence: June 4, 1932, Frison & 

 Mohr, 1 $ . 



Triaenodes flavescens Banks 



Triaenodes flavescens Banks (1900^, p. 257); 



Larva. — Unknown. 



Adults. — Length 12 mm. Color tawny 

 with the cream and brown wing pattern 

 shown in fig. 863. Male genitalia, fig. 846, 

 similar in general structure to tarda, differ- 

 ing in the long, bladelike tenth tergite and 

 the claspers with the shorter, pointed lateral 

 projection and the larger mesal lobe. Fe- 

 male genitalia, fig. 859, similar in general 

 structure to tarda, differing chiefly in having 

 one internal fold beyond the base of the 

 claspers sclerotized. 



Allotype, female. — Wilmington, Illinois: 

 Aug. 20, 1934, DeLong & Ross. 



In Illinois we have taken only one collec- 

 tion of this species; it bears the same data 

 as given for the allotype and contains two 

 males and four females. Little is known 

 regarding the habits of the species. 



Its range includes the northeastern states, 

 with records from Illinois, New Jersey, 

 New York, Ohio and Pennsylvania. 



