is a possible 1-year-early emergence of the 17- 

 year Northern Illinois Brood (Marlatt's XIII) 

 of 1905. 



1932. Urbana, Champaign County, Universit\' Woods, 

 September 6. Rocky Branch, Clarksville, Clark 

 County, June 24. These are possibly 1-year- 

 early emergences of the 13-year Great Southern 

 Brood (Marlatt's XIX) of 1933. 



1957. Sullivan, Moultrie County, "late in season," 

 H. B. Cunningham, six specimens. This is pos- 

 sibly a P/2-year-early emergence of the 13-year 

 Great Southern Brood (Marlatt's XIX) of 1959. 



1969. Lisle, DuPage County, June 6, L. J. Stannard, 

 just emerged at edge of a lowland woods in 

 Morton Arboretum. Chicago Heights, Cook 

 County, June 11, H. B. Petty. Chicago area, 

 many specimens reported to the Natural His- 

 tory Survey extension staff. (See Dybas 1969 

 for extensive list of localities in the Chicago 

 region.) These are assumed to be 4-year-early 

 emergences of the 17-vear Northern Illinois 

 Brood (Marlatt's XIII) of 1973. 



1971. Barry, Pike County, June 9, J. Cruttenden, 

 several specimens. Tentatively assigned to 

 M. tredecassini by T. E. Moore (personal com- 

 munication 1971). These are probably 1-year- 

 early emergences of the 13-vear Great Southern 

 Brood (Marlatt's XIX) of 1972. Mr. Cruttenden 

 recalls the presence of this brood in the area 

 in 1959. 



1972. Lisle, DuPage County, October 12, J. Appleby, 

 one adult next to its shed skin, emerged after 

 flood in Morton Arboretum. This is possibly a 

 half-year- early emergence of the 17-year North- 

 em Illinois Brood (Marlatt's XIII) of 1973. 



1973. Mahomet, Champaign County, Nettie Hart 

 Memorial Woods, June 6, M. W. Sanderson. 

 This is a possible 1-year-late emergence of the 

 13-year Great Southern Brood (Marlatt's XIX) 

 which emerged in 1972. 



1974. Lisle, DuPage County, Ma>' 29, J. Appleby, 

 one adult on bush. Ohio, Lee County, May 23, 

 Gene R. Kritsky, one adult in flight hit car. 

 These are probably 1-year-late emergences of 

 the 17-year Northern Illinois Brood (Marlatt's 

 XIII). 



Other supposed stragglers in the USA have been 

 listed by Alexander &: Moore (1962) and in the Chi- 

 cago area by Lloyd &: Dybas (1966i>). 



DISTRIBUTION OF 

 THE BROODS OF ILLINOIS 



Because many of Marlatt's broods probably do 

 not exist and because several numbering systems, each 



differing from the others, have been used, the Illinois 

 broods listed here are designated by geographical 

 names with the corresponding Marlatt numbers for 

 easy reference. These geographical names should 

 be more meaningful than numbers and indicate re- 

 lationships with populations outside the state. 



The lowan Brood (Marlatt's III) 



The lowan Brood has a 17-year cycle and most 

 recently emerged in 1963. Records (Fig. 1) were ob- 

 tained from May 26, 1963 along the Spoon River, 



Fig. 1. — Distribution of periodical cicadiis in Illinois. 

 The two upper enclosed areas show the locations of the 

 lowan Brood (Marlatt's III), and the two lower enclosed 

 area.s indicate the locations of the Lower Mississippi River 

 Valley Brood (Marlatt's XXIII). Black dots indicate posi- 

 tive records of adult specimens, skins, holes in the ground, 

 flagging tree branches, or singing. Circles indicate negative 

 records in areas carefully searched. 



