24 



PAPEES ON CEREAL AND FORAGE INSECTS. 



and in parts of Illinois. Prof. T. D. A. Cockerell found a few speci- 

 mens of both the long-winged and the short-winged forms at Mesilla 

 Park, N. Mex.; Messrs. E. A. Schwarz and H. S. Barber, of this 

 bureau, found a few short- winged forms at Hot Springs, Yavapai 

 County, Ariz.; Mr. George I. Reeves found some long-winged forms 

 in southwestern Washington; and Mr. Albert Koebele and Dr. P. R. 

 Uhler found a few at San Francisco and Alameda, Cal., and. also in 

 Lower California. Prof. Herbert Osborn found the short-winged form 

 at Sault Ste. Marie, Mich., and Mr. Herbert T. Osborn found it at 

 Wellington, Kans. 



H- WESTERN & SOUTHERN LIMIT OF DESTRUCTIVE. OUTBREAKS. 

 jUJgrAREA OF GREATEST INFESTATION DURING 190 9 AND I9IO. 



= LOCALITIES WHERE CHINCH. BU6S HAVE 



BEEN FOUND OUTSIDE OF AREA OF 6ER.IOU5 

 INFESTATION. 



Fig. 11.— Map showing distribution of the chinch bug west of the Mississippi River, 1911. (Original.) 

 DESCRIPTION AND NUMBER OF GENERATIONS. 



Full descriptions of this insect are found in Bulletin No. 69 and in 

 Circular No. 113 of this bureau and will not be repeated here. 



There are two principal generations annually in the Middle West; 

 the spring generation and the fall, or hibernating, generation, and a 

 partial third generation sometimes occurs in late fall to the south- 

 ward. 



MIGRATIONS. 



The hibernating bugs (fig. 14) issue from their winter quarters as 

 soon as the sun warms up the grasses in the spring, and fly out to 

 green grasses and young wheat and barley, where they feed, mate, 

 and deposit their eggs. The eggs (fig. 13 a, h) begin to hatch in late 

 April and continue hatching until June, varying with the seasonal tem- 

 perature and the latitude of the locality affected. The young bugs 



