1924 ENTOMOLOGICAL SOCIETY 79 



has been wholehearted and with the exception of some assistance in the spring 

 of 1921 in the cleaning up of the barnyards, the work has all been done by the 

 growers. 



The suggestions made for the control were those indicated as likely to be of 

 the greatest value by the investigations carried out by the Departments of 

 Agriculture of the Dominion of Canada and the Province of Ontario, and reported 

 upon to this society in 1921 by Mr. G. J. Spencer. Briefly, they may be referred 

 to as the farm clean-up and the practice of late planting. The clean-up implied 

 that all refuse from one year's crop is either underground or burned by the first 

 of June of the following year, while the planting was advised to be as late as was 

 safe in the community with the assurance of getting a good crop. The early 

 fall frosts were, the chief limiting factors in determining lateness of planting. 



In general in the area between St. Thomas and the Lake Erie shore, the 

 attack in 1920 was the most intense suffered until that time and was a decided 

 increase over any previous attack. Farmers had become worried and the first 

 volunteer information was received late in the season from near St. Thomas. By 

 this time, however, farmers in the Union area were growing corn with 99 per cent. * 

 infestation without official complaint, and the sweet corn in the district was 

 most severely infested. 



The next year the investigations opened with vigour and the area was 

 brought under constant and careful study. Hence our information from this 

 time on is much more detailed. 



In 1921, the attack increased very markedly in intensity, the average 

 infestation for six farms studied in 1920 rose from 77.2 per cent, to 85 per cent, 

 and the stalk infestation for the field corn in the whole control area (four square 

 miles — 45 fields) was 58.17 per cent. Many fields of flint corn were 100 per cent, 

 infested and ruined. Dent corn attained an infestation of 78 per cent., and from 

 over twenty acres of early market sweet corn the product was a total loss, as it 

 was not worth while culling the crop for the few saleable ears. 



In 1922 (37 fields), conditions within the control area following the first 

 control efforts in the fall of 1921 and spring of 1922 presented an entirely different 

 aspect. The average infestation dropped to 26.25 per cent., and the cob injury 

 and other manifestations of the attack decreased markedly. Comparing the 

 attack with that of 1921 there was a most remarkable decrease in intensity and 

 loss. The infestation of the market sweet corn was still high where planted 

 early, though where planted late was commercially profitable. However, as 

 there was almost no sweet corn grown on account of the destruction of 1921, it 

 hardly serves for valid comparison. 



Throughout the general district surrounding the control area there was a 

 marked increase in the infestation. This was most noticeable to the west in the 

 Fingal region, and to the east in the Dexter region. To the north the increase 

 was not as abrupt though it was quite distinct; southward the infestation 

 decreased as a large proportion of the few growers in this region were putting the 

 control methods into operation. In general, although careful systematic studies 

 were not made in the fields surrounding the control area, it was conspicuous that 

 the infestation definitely increased upon the northern, western and eastern sides 

 of the area. Fields much more intensely infested than any within the control 

 area were easily found even within a few hundred yards of its margin. 



*The percentage infestation of stalks refers to ear-bearing stalks unless otherwise noted. 



