160 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 1 



gus very long, neck long and narrow, spiral 

 long, apex with a pair of appressed sclero- 

 tized hooks. Female genitalia, fig. 555: 

 eighth sternite without central ornamenta- 

 tion; bursa copulatrix with an elongate, 

 tenpin-like process. 



Our only Illinois record of this species is 

 a large collection of males, females and 

 pupae from Lusk Creek near Eddyville, 

 June 19-20, 1940, Mohr & Riegel. These 

 were taken in company with okopa and 

 riegeli. Lusk Creek is a clear, rapid stream 

 in the Ozark Hills of southern Illinois. 



The only available records are from Illi- 

 nois, Kentucky and New York. 



Mayatrichia Mosely 



May atrichia Mosely (1937, p. 182). Geno- 

 type, by original designation: Mayatrichia 

 ayama Mosely. 



This genus contains three North Ameri- 

 can species, of which only one, ayama, has 

 been taken in Illinois. The other two are 

 known from Oklahoma and Texas. The 

 three species are readily distinguished on the 

 basis of male genitalia, but differences be- 

 tween the females have not yet been worked 

 out. A key to the males, followed by de- 

 scriptions of the out-of-state species, is given 

 on p. 278. 



Mayatrichia ayama Mosely 

 Mayatrichia ayama Mosely (1937, p. 182); 



Larva (mature type). — Fig. 557. Length 

 2 mm. Head and body sclerites cream col- 

 ored with only a few slightly darker lines 

 around the edges of some sclerites; body 

 white. Similar in general to Neotrichia, with 

 cone-shaped head and slender legs. Abdomen 

 wedge shaped, with lateral contours very 

 even and possessing lateral fringe, similar 

 in this respect to the Leptoceridae. 



Larva (free-living young form). — Fig. 

 557. Similar to mature type but with ab- 

 domen small and tapering, all segments par- 

 tially sclerotized and provided with stout 

 setae. Anal legs close together at base, fig. 

 552, claws as in mature form. 



Case. — Fig. 558. Somewhat wedge shaped, 

 fibrous, ventral surface flat, dorsal surface 

 convex, raised into either longitudinal ridges, 

 transverse ridges, or sometimes a combina- 

 tion of both. Posterior end closed; anterior 



end sealed for pupation by a circular, brown, 

 membranous cap. 



Adults. — Length 2-3 mm. Color brown 

 without conspicuous markings. Sixth seg- 

 ment with a long, slender spine, fig. 559. 

 Male genitalia, fig. 929, p. 279; ninth seg- 



Fig. 557. — Mayatrichia ayama. A, free 

 living, early instar; 5, case making, later instar. 



Fig. 558. — Mayatrichia ayama, case. 



