August, 1944 



Ross: Caddis Flies of Illinois 



235 



tral membranous "curtain" hanging down 

 on the ventral side of the bursa. 



Allotype, female. — Lake Erie, Put-in- 

 Bay, Ohio: 1937. 



Our only definite records for this species 

 are two females collected at Chicago, Illi- 

 nois, one on July 8, 1937, along the lake 

 front, Prison & Ross, the other on June 24, 

 1925, A. C. Weed, fm. There is a third 

 female bearing the data "Northern Illinois," 

 but without other information. 



The species was originally described from 

 Lake Erie, where it is very abundant; other- 

 wise it is known only from Quebec and 

 Illinois. 



Athripsodes erraticus Milne 



Athripsodes erraticus Milne (1936, p. 58); 



Larva. — Unknown. 



Adults. — Length 12 mm. Color black 

 or nearly so, the anterior wings with a 

 scattering of white scales. Male genitalia, 

 fig. 777: tenth tergite divided into dorsal 

 and ventral portions, the ventral portion 

 with a lateral long curved blade; claspers 

 with a large mesal lobe which is serrate with 

 evenly spaced teeth on the mesal margin. 

 Female genitalia, fig. 807: ninth sternite 

 only slightly sclerotized; bursa copulatrix 

 U-shaped with a pair of lateral points at 

 middle and above these forming a slightly 

 narrower, vasiform part. 



Our only Illinois record of this species is 

 a female bearing the data "Northern Illi- 

 nois." The species is present in Lake Erie 

 and has been taken in Quebec. 



Athripsodes erullus Ross 



Athripsodes erullus Ross (1938^, p. 90); cf. 



This species has not yet been taken in Illi- 

 nois, but since it is common in company with 

 both saccus and erraticus in Lake Erie, we 

 might expect it in the northern part of the 

 state. The male genitalia, fig. 778, are read- 

 ily distinguished on the basis of characters 

 in the key. The females resemble the males 

 in black color and the white scales on the 

 wings. They are readily distinguished from 

 those of other species by the curious struc- 

 ture of the bursa copulatrix and the division 

 of the ninth sternite into three fairly large 

 areas, fig. 804. 



Allotype, female. — Lake Erie, Put-in- 

 Bay, Ohio: 1937. 



Athripsodes sub macula (Walker) 

 Leptocerus submacula Walker (1852, p. 70): 



This species, like errulus, has not yet been 

 taken in Illinois, although in Lake Erie it 

 occurs in company with erraticus and saccus. 

 As outlined by Betten & Mosely (1940, p. 

 70), only the male of the type series can 

 be definitely assigned. Study of much ma- 

 terial from Lake Erie shows that the female 

 has the black head and white-scaled wings 

 typical of the group, and small eyes, al- 

 though slightly larger than eyes of related 

 females; the ninth sternite is divided into 

 extensive lateral lobes which are only mod- 

 erately sclerotized, and the bursa copulatrix 

 is heavily sclerotized and triangular, fig. 

 803. 



Allotype, female. — Lake Erie, Put-in- 

 Bay, Ohio: 1937. 



Athripsodes species a, b and c 



In addition to the larvae associated defi- 

 nitely with adults, there are three species 

 of larvae segregated in our collection which 

 have not been reared. Most likely these 

 belong to species here treated in the adult 

 stage only, which include angustus, ophio- 

 derus, resurgens and the entire complex of 

 species with white-scaled wings such as 

 punctatus and erraticus. These unreared 

 larvae have been included in the key as an 

 aid to the better recognition of the reared 

 species and a stimulus for additional rear- 

 ing work. 



Species a. — Length 6 mm. Almost en- 

 tirely straw colored, the sclerites scarcely 

 darker than the body. Parafrontal areas 

 indistinguishable. Mesonotum with only a 

 few hairs in addition to lateral tufts of two 

 or three hairs. This species makes a short 

 horn case using fragments of fresh-water 

 sponges in its construction so that it appears 

 irregular, soft and fuzzy. We have taken 

 this species in Nippersink Creek at Spring 

 Grove, Illinois, in the Namekagon River 

 at Spooner, Wisconsin, and in Meramec 

 Springs at St. James, Missouri. This last 

 collection had cases made of irregular pieces 

 of stones and very little sponge material. 



Species b. — Length 5 mm. Head, prono- 



