August, 1944 



Ross: Caddis Flies of Illinois 



39 



general characteristics, and in general ap- 

 pearance differ from each other chiefly in 

 size. The adults are secretive in habit and 

 are very seldom captured except around 

 their stream; the notable exception is Pro- 

 toptila, which is taken frequently at lights 

 in large numbers. 



The larvae of this entire subfamily are 

 very uniform in shape and appearance, dif- 

 fering chiefly in the characters mentioned 

 in the key to genera. Reliable characters 

 have not yet been discovered in the larvae 

 for separating the species within the genus. 



Glossosoma Curtis 



Glossosoma Curtis (1834, p. 216). Genotype, 

 monobasic: Glossosoma boltoni Curtis. 



Mystrophora Klapalek (1892, p. 19). Geno- 

 type, monobasic: Mystrophora intermedia 

 Klapalek. New synonymy. 



The group of species with the short and 

 platelike apical spur on the hind tibiae of 

 the male has usually been considered as a 

 separate genus, Mystrophora. Since there 

 appears to be no corresponding diagnostic 

 character in either the females or larvae, 

 I am considering this division as of sub- 

 generic importance at the most. 



Only one species has been captured in 

 Illinois; two others occur in the eastern 

 states and many are known from the Rocky 

 Mountain region. 



Glossosoma intermedium (Klapalek) 



Mystrophora intermedia Klapalek (1892, p. 

 19). 



Larva. — Fig. 136. Length 6-9 mm. Head, 

 pronotum, legs and anal sclerites dark 

 brown, body pinkish to very light brown. 



Adults. — Length 7-10 mm. Body ap- 

 pendages dark brown, appearing almost 

 black. Male with a flattened apical spur 

 on hind tibiae, fig. 140. Male genitalia, 

 fig. 138: tenth tergite divided to base into 

 large lobes pointed at apex and provided 

 at base with a long, sclerotized rod; claspers 

 narrow at base, expanded at apex. Female 

 genitalia, fig. 139, typical in general propor- 

 tions for subfamily; eighth sternite deeply 

 incised to form a deep, narrow V on meson. 



This species, described and recorded from 

 various points in Europe, has recently been 

 found in Illinois, Minnesota and Missouri. 

 In Illinois, it is apparently confined to the 



;/vv/:r•V.v.'.■^N^■Jl 



:;//<:': 



Fig. 138. — Glossosoma intermedium, male 

 genitalia. //, dorsal aspect; B, lateral aspect. 



Fig. 139. — Glossosoma intermedium, female 

 genitalia. ^4, lateral aspect; B, ventral aspect. 



Fig. 140. — Glossosoma intermedium cf, spur 

 of hind tibia. 



small set of spring-fed brooks in the Elgin 

 Botanical Gardens, where the species occurs 

 in such numbers that the cases literally pave 

 the bottoms of the streams. 



Illinois Records. — Elgin: April 19, 1939, 

 Burks & Riegel, 1 pupa; May 9, 1939, Ross 

 & Burks, $ $ , $ $ , many pupae and 

 larvae; May 23, 1939, Burks & Riegel, 

 3^,19; June 6, 1939, Burks & Riegel, 2 $ , 

 3 9 ; June 13, 1939, Frison & Ross, 6^,79 ; 

 Sept. 19, 1939, Ross & Mohr, $ $ , 9 9, 

 many larvae and pupae; March 20, 1940, 

 B. D. Burks, 5 (J , 2 9 , 1 $ pupa, 1 mating 

 pair; all of preceding Elgin records from 

 Botanical Gardens; Rainbow Spring, May 

 19, 1939, Ross & Burks, 3^, 29. 



Agapetus Curtis 



Agapetus Curtis (1834, p. 217). Genotype, by 

 subsequent designation of Westwood (1840, p. 

 51): Agapetus Juscipes Curtis. 



Only one species, ill'ini^ has been taken 

 in Illinois. Three other species occur in 



