228 



Illinois Natural History Survey Bulletin 



FoL 23, Art. 1 



Case.— Fig. 808. Length 9 mm., 4.5-5.0 

 mm. wide, built solidly of sand grains, the 

 dorso-lateral margins produced into a wide 

 flange so that from above the case appears 

 shaped like a water-penny. 



Adults. — Length 11 mm. Color medium 

 to dark shades of brown without conspicu- 

 ous markings on scales. Male genitalia, fig. 

 774: cerci short and tenth tergite long; 



Fig. 808. — Athripsodes ancylus, case. 

 Fig. 809. — Athripsodes ?flavus, case. 

 Fig. 810. — Athripsodes mentieus, case. 



claspers with a long prolongation of the 

 base, as seen from ventral view forming a 

 stout, curved, pencil-like pair of appendages, 

 the remainder of the clasper upright, long 

 and slender with a short mesal process and 

 apical segment only slightly longer than the 

 process. Female genitalia, fig. 795, with 

 the ninth sternite divided into a pair of 

 heavily sclerotized, markedly concave plates 

 which are produced into a sharp apico-mesal 

 point; bursa copulatrix as in fig. 7955. 



We have only scattered records of this 

 species from Illinois, from some of our best 



aquatic habitats in the northern, central and 

 southern parts of the state. All the material 

 we have, both in Illinois and in other states, 

 has a case conforming quite exactly to the 

 above description. Lloyd (1921, p. 96) re- 

 cords a case markedly different in shape, 

 but we have seen nothing that agrees with 

 his description. Our larvae were collected 

 in wide extremes of environment, including 

 weed beds in the northeastern glacial lakes, 

 and under stones in the rapid streams of the 

 Ozark Hills. Adult emergence apparently 

 is confined to May, June and July; this 

 indicates a single generation per year. 



The species is distributed widely through 

 the northern and eastern states and also 

 occurs in the Kiamichi Mountains in Okla- 

 homa. Available records include Georgia, 

 Illinois, New York, North Carolina, Ohio, 

 Oklahoma and Wisconsin. 



Illinois Records. — Chicago: July 8, 

 1939, G. T. Riegel, 1 $ . Eddyville, Lusk 

 Creek: May 24, 1940, Mohr & Burks, 1 

 pupa. Fox Lake: May 15, 1936, from 

 weeds, Ross & Mohr, 2 larvae. Golconda: 

 May 30, 1928, at light, T. H. Frison, 1 $ . 

 JoHNSBURG, Fox River: May 10, 1938, 

 Ross & Burks, 2 cases. Momence: June 4, 

 1932, Frison & Mohr, 1^. Wilmington: 

 July 1, 1935, DeLong & Ross, 1^. 



Athripsodes flavus (Banks) 



Leptocerus flavus Banks (1904^, p. 212); cf, 

 9. 



Larva. — We have no definite rearing of 

 this species but have taken several collec- 

 tions of a larva which is closely related to 

 ancylus, differing in the wider lateral exten- 

 sions of the case and the uniformly paler 

 color of the larval sclerites. Since this spe- 

 cies displays the proper taxonomic charac- 

 ters for such a placement and in addition is 

 slightly smaller than ancylus, I am regard- 

 ing this larva tentatively as flavus. The case 

 is 8 mm. long and 5.5-6.0 mm. wide, fig. 809. 



Adults. — Length 9 mm. Color various 

 shades of light brown without conspicuous 

 markings or white scales. Male genitalia, 

 fig. 775, distinguished by the long basal pro- 

 jection of the clasper, which in this species 

 is sharply angled at the base. Female geni- 

 talia, fig. 794, with the sclerotized halves 

 of the ninth sternite sharply tapered to base, 

 the lateral margin sharply angulate; bursa 

 copulatrix with sides appressed to body so 

 that, from ventral view, they do not flare. 



