August, 1944 



Ross: Caddis Flies of Illinois 



121 



Male genitalia, fig. 916, (see p. 272) : eighth 

 sternite bilobed, forming a pair of widely 

 spaced triangles; ninth tergite with a brush 

 of long setae; claspers fused to form a short, 

 broad spatula; aedeagus as in fig. 916. Fe- 

 male genitalia with segments simple; bursa 

 copulatrix as in fig. 921 (see p. 273). 



The larva was described by Lloyd 

 (1915fl) under the name Itliytricliia confusa 

 (misidentification) . 



Our only Illinois records of this species 

 are from the Apple River in Apple River 

 Canyon State Park, situated in the Jo 

 Daviess hills of extreme northwestern Illi- 

 nois. In one or two of the swiftest rapids 

 of the river we have taken larvae and pupae 

 on large stones in the center of the current. 



In the northern states, the species' range 

 is practically transcontinental, with definite 

 records from Colorado, Idaho, Michigan, 

 Minnesota, New York, Oregon, Wisconsin 

 and Wyoming. 



Illinois Records. — Apple River Can- 

 yon State Park: Aug. 23, 1939, Ross & 

 Riegel. 1$, 2$; Apple River, May 24, 

 1940, H. H. Ross, \ $ , 2 larvae, many pu- 

 pae ; June 6, 1940, Mohr & Burks, 2$ ; 

 April 9, 1941, Ross & Mohr, many larvae. 



Metrichia Ross 



Metrichia Ross (1938<r, p. 9). Genotype, by 

 original designation: Orthotrichia nigritta 

 Banks. 



The genotype is the sole species in the 

 genus and is known from Texas and Okla- 



Fig. 451. — Metrichia nigritta. //, wings; 

 B, male genitalia. 



homa. The larva is unknown. The male 

 genitalia and wings are illustrated in fig. 

 451. 



Dibusa Ross 



Dibusa Ross (1939«, p. 66). Genotype by 

 original designation: Dibusa angata Ross. 



In this genus, as in Metrichia, the geno- 

 type is the sole species. Originally described 



Fig. 452. — Dibusa angata. A and 5, male genitalia, lateral and dorsal aspects; C, aedeagus; 

 D, wings. 



