SUMMARY OF INSECT CONDITIONS DURING 1921. 



29 



did not appear during the summer of 1921, but as the southwestern 

 corner of that State is in the direct path of the natural spread of the 

 insect, it may be expected that this territory will become infested 

 by natural means in the immediate future. The infestation pre- 

 vailing in corn in the most intensely infested part of the old area of 

 infestation in Massachusetts is practically unchanged. On the other 

 hand, a considerably higher degree of infestation has occurred in the 

 case of other cultivated crops, including especially vegetables and 

 flowers. It is estimated that the loss to corn in this heavily infested 

 area as a direct result of the injury of the insect ranged from 8 to 



Fig. 14.- 



-Geographical distribution of the European corn borer in the United States and 

 Canada in 1921, shown by black areas. 



20 per cent of the total value of the crop. Outside of this heavily 

 infested area and in some fields within it, little or no commercial 

 damage has as yet occurred to the ears of either sweet or field corn. 

 In the eastern Xew York area in the vicinity of Schenectady and 

 Albany, the infested area comprises 2,203 square miles. The com- 

 mercial injury here has as yet been almost negligible. Xot more 

 than 1 per cent of the ears of corn from infested fields were dis- 

 carded as unmarketable on account of corn-borer injury. The degree 

 of infestation in sweet corn in this area was slightly greater than in 

 1920. In western New York, in the vicinity of Buffalo and Dun- 

 kirk, an area which is now continuous with the infested areas in 



