1923 ENTOMOLOGICAL SOCIETY. 13 



In regard to the European Corn Borer infestation in the United States it 

 may be said that, since its discovery in 1917, the insect has spread over a large 

 area, and particularly in Massachusetts has been responsible for a great deal 

 of damage not only to corn but also to other crops. When first discovered in 

 Massachusetts, Vinals reports corn as "the only valuable commercial crop seri- 

 ously attacked by this pest." He mentions it as also attacking pigweed, barn- 

 yard and foxtail grass and dahlia stems. But conditions have changed, and the 

 insect is now doing serious damage to beets, celery, beans, chrysanthemums, 

 etc. In fact the list of host plants in the Massachusetts area is now one hundred 

 and seventy.* 



The following table illustrates the spread of the European Corn Borer in 

 the United States: 5 



Year 



No. 



Twp. 



Inf. 



States Infested 



1918 



1919 



1920 



1921 



1922 



Total... 





32 



122 



105 



127 



177 



563 





Massachusetts 



Mass., southern New Hampshire, central and western New 



York, and Pennsylvania (1). 

 Mass., N.H., and N.Y. 



Mass., N.H., N.Y., Penn., Ohio and Michigan. 

 Mass., N.H., N.Y., Penn., Ohio, Mich., Maine, and Rhode Island 



Now that the European Corn Borer has invaded the corn growing sections 

 of Ontario, it is to be hoped that it will continue to confine its activities to corn 

 and not attack other plants to the same extent as it has done in Massachusetts, 

 for up to the present time in Ontario corn has been the only plant seriously 

 injured; but time alone will solve this question. 



PLOUGHING AS A FACTOR IN THE CONTROL OF THE EUROPEAN 

 CORN BORER IN ONTARIO 



H. G. Crawford, Entomological Branch, Dominion Department of 



Agriculture, Ottawa 



During the preliminary investigation of the European Corn Borer it was 

 noted that the larvse, when buried with infested corn stalks under certain condi- 

 tions, subsequently came to the surface of the ground. This was inferred in 

 1921, and clearly demonstrated in 1922. The weakness in the 1921 data was 

 that the larvae emerging from below ground were not recovered. 



With this shortcoming in mind, the 1922 studies were carried on with a 

 view to recovering the larvae as they came to the surface after the corn refuse 

 had been buried or ploughed down. 



The technique of the study was simple. It consisted in burying, by hand 



3 S.C. Vinal, The European Corn Borer, Bulletin 178, Massachusetts Agriculture Experi- 

 ment Station, December, 1917. 



4 E. P. Felt, The European Corn Borer, Extension Bulletin 31, New York State College 

 of Agriculture, Revised March, 1922. 



5 W. N. Keenan, The Distribution of the European Corn Borer in Canada and the United 

 States. Ann. Rept., Que. Soc. Prot. Plants, 1921-22. Also from Quarantine No. 43 of the 

 United States Department of Agriculture (2nd Revision), May 1st, 1922, with amendments to 

 November 16th, 1922. 



