PROGRESS REPORT OX THE EUROPEAN CORN BORER 13 
east of and including the Mississippi River basin States, as well as 
in Texas, New Mexico, and Arizona. Particular attention has been 
given localities where imported broomcorn was known to have been 
received, as well as to sections producing field corn, sweet corn, and 
broomcorn. Special scrutiny has been given the territory adjacent 
to ocean and river ports and railroad centers and along the main 
railroad, highway, and water routes. 
DISTRIBUTION IN THE DOMINION OF CANADA 
During August, 1920, the Canadian authorities reported the dis- 
covery of an infestation by the European corn borer in Welland 
County, Ontario, along the Niagara Eiver immediately opposite the 
western New York area of infestation, and another .larger and more 
heavily infested area along the Canadian shore of Lake Erie, with 
its apparent center near St. Thomas, Ontario. 
At the close of 1924 the pest was present in an area of approxi- 
mately 18,000 square miles, comprising the entire southern Ontario 
peninsula bordering Lake Erie and including Pelee Island in the 
lake. The area of infestation in Ontario was practically continuous 
with the area of infestation on the United States side of Lake Erie. 
(See map, fig. 1.) 
The character of the infestation in Middlesex and Elgin Counties, 
Ontario, was more severe than in any of the areas in the United 
States, with the exception of that existing in New England, and, 
according to Crawford and Spencer (12), very severe losses occurred 
to flint field corn and to sweet corn, whereas dent field corn in gen- 
eral suffered to a lesser extent. 
The presence of this large and severely infested area directly 
across Lake Erie from American territory constitutes a source of 
possible further dispersion to the lake regions of New York, Penn- 
sylvania, Ohio, and Michigan, through both the natural and artificial 
spread of the insect. The severe character of the infestation in part 
of Ontario is also indicative of conditions which may be expected 
eventually to develop on the American side of the lake, as the cli- 
matic and agricultural conditions are similar. 
PROBABLE MANNER OF IMPORTATION 
The precise manner in which the European corn borer gained 
entrance to the United States is not definitely known, but as a result 
of investigations conducted since its original discovery in New 
England, it is believed that broomcorn which was imported for 
manufacturing purposes from Hungary or Italy during the period 
from 1909 to 1914 was the probable carrier (58). At this time the 
conditions of the trade were such that unusually large quantities of 
broomcorn were imported, the report of the Bureau of Foreign and 
Domestic Commerce, Department of Commerce, showing that at 
least 12,000 tons were received during this period. Broomcorn is 
known to be commonly infested by P. mibilalis in both Hungary and 
Italy, where much of this material originated. The inspection 
service was not authorized by law until 1913, and therefore it was 
not possible to intercept this material upon its arrival at the ports 
of entry. 
