:. THE HESSIAN FLY... a 
_bave been first introduced into the Paecifie coast region. in or with 
articles of inland commerce, and, unless it be found to infest native 
grasses, that it did not reach there by natural diffusion, a point that 
has not before been definitely stated so as to be clearly understood. 
Hxpermental sowings of wheat near Sault Ste. Marie, Mich., dur- 
ing the years 1904 and 1905 do not reveal its presence there, and no 
attempt has been made to study its occurrence in the spring-wheat- 
growing sections of Maine. While its absence in some parts of the 
country between the Platte River, in Nebraska, and the Canadian 
boundary line might be attributed to a lack of its food plant, this will 
not hold in southwestern Kansas and Okiahoma, as in those localities 
it seems to terminate suddenly in the midst of a wheat-growing sec- 
Fre. 8.—Map showing distribution of the Hessian fly in the United States in 1914. (Original.) 
tion, and where this grain has been cultivated for at least twenty 
years. Strange as this may at first appear, Dr. C. Hart Merriam, 
formerly Chief of the Biological Survey of the U. S. Department of 
Agriculture, informed the writer that he has found several parallel 
cases in the distribution of some of the smaller mammals. 
FOOD PLANTS. 
The chief food plant of the Hessian fly is wheat, next to this barley, 
and lastly rye. In the last plant, however, it does not develop freely, 
and it does not attack oats at all. Many years ago Lindemann, in 
Russia, found what he determined as the flaxseeds of the Hessian 
fly on timothy and Agropyron repens. Later Mr. Albert Koebele 
found flaxseeds closely resembling those of the Hessian fly on Ely- 
mus, Agrostis, Bromus, and-Agropyron in California. Still later 
