572 



U. S. NATIONAL MUSEUM BULLETIN 216 



2a. Spilopteron formosum formosum (Cresson) 



Figure 328,d 



Arotes formosum Cresson, 1868, Canadian Ent., vol. 1, p. 34; <?• Type: d", 

 Ottawa, Ont. (Philadelphia). 



The key states the differences between this subspecies and the next. 



In two of the males reared at Inglenook, Pa., reported below, the 

 coloration is more like that of S. formosum australe than of the present 

 subspecies. They are assigned to the subspecies formosum, however, 

 because they are within its range and because the coloration may 

 have been shifted toward that of the subspecies australe by abnormal 

 climatic conditions in the laboratory, rather than by genetic factors. 

 Though these two and other specimens show that the subspecific 

 distinction is tenuous, it nevertheless seems a useful one for separating 

 a generally northern from a generally southern population. 



Specimens (12 c? 1 , 279): From Connecticut (Colebrook) ; Manitoba 

 (Treesbank); Michigan (Ann Arbor, Floodwood in Dickinson Co., and 

 Mecosta Co.); Minnesota (Cass Co. and Kittson Co.); New Jersey 

 (Alpine); New York (Bluff Island near Clayton and West Point); 

 Ohio; Ontario (Ottawa, Bells Corners, and Thunder Bay Beach); 

 Pennsylvania (Clarks Valley near Dauphin, Harrisburg, and Ingle- 

 nook in Dauphin Co.); Quebec (Aylmer, Covey Hill, Montreal, 

 North River near St. Adele, and Wakefield); Vermont (Laurel Lake 

 near Jacksonville and West Rupert); and West Virginia (Lewisburg). 



Most collecting dates are in July but there are a number in June 

 and August. The earliest and latest dates are: June 5 in Clarks 

 Valley, near Dauphin, Pa.; June 6 in Ohio; June 11 at West Point, 

 N. Y.; June 27 at Alpine, N. J.; August 12 in Kittson Co., Minn.; 

 August 18 at Treesbank, Man.; August 19 at Lewiston, W. Va. ; 

 and August 21 at Wakefield, Que. 



Figure 278, 279.- 



-Localities: 278 (left), Spilopteron formosum formosum; 279 

 (right), S. f. australe. 



