/<S6 



Invt'itt'hrtih's — Oitr Livtiii^ Rt-scurces 



Table . Relative abundance of 

 Illinois stoneflies. R — rare ( 1-3 

 localitiesi; U — uncommon (4-14 

 localities); and C — common 

 (more than 14 localities). 

 Surnames within or outside paren- 

 theses refer to the authors of the 

 species name. 



Species 



Relative abundance 



Species 



Relative abundance 



Group Euholognaiha 



Capniidae 



Capniinae 



Allocapnia 



forbesi Prison 

 granulala (Claassen) 

 illinoer.sis Prison 

 myslica Prison 

 nivicola (Fitch) 

 recla (Claassen) 

 rickeri Prison 

 smithi Ross S Ricker 

 vivipara (Claassen) 



Nemocapnia 



Carolina Banks 



Paracapnia 



angulata Hanson 



Leuctridae 

 Leuctrinae 

 Leucira 



rickeri James 



sibleyi Claassen 

 tenuis (Pictet) 

 Zealeucira 



claasseni (Prison) 

 Iraxina Ricker & Ross 

 narfi Ricker & Ross 



Attaneuria 



ruralis (Hagen) 

 Perlesta 



decipiens (Walsh) 

 Perlinella 



its distribution, as this species is found com- 

 monly across the Shawnee Hills. The apparent 

 or possible extirpation of 10 species of stone- 

 flies from Illinois creates serious concern. None 

 of the species were collected in Illinois during 

 1990-94, although we are still unsure about the 

 extirpation of four of these species, since they 

 are large-river species and we are not satisfied 

 w ith our collecting techniques for these habitats. 

 In evaluating the changes in spatial distribu- 

 tion of Illinois stoneflies, the "winter stone- 

 flies," in particular, the genus Allocapnia, offer 

 the best examples (Prison 1929, 1935, 1937, 

 1942: Ricker and Ross 1968. 1969: Ross and 

 Ricker 1971: Webb and Hams 1993). One strik- 

 ing example is A. gramilata. In the I920's, 30"s, 

 and 60"s, this species was distributed and abun- 

 dant from southeastern to northern Illinois. A 

 drastic reduction in the distribution of this 

 species has occurred since 1970, and in the past 

 4 years, this species has only been collected 

 within the Rock River drainage of northern 



