1918.] PUBLIC DOCUMENT — No. 31. 53a 



was collected by the inspectors during this past year on stock 

 from two different points abroad. 



A new pest, the European corn borer, which from present 

 knowledge is capable of causing severe injury to the corn crop, 

 was this season found to be firmly established in the district 

 immediately around Boston. Taking into consideration the 

 damage to corn in the more or less restricted area infested dur- 

 ing the past season, we can readily foresee the terrible losses it 

 would cause should it ever be able to spread to the large corn 

 fields of the West. A study of the nature of its attack and life 

 history, together with a survey of the infested region, was 

 undertaken, and a preliminary paper giving information thus 

 far obtained has been published. More extensive work is 

 planned for the coming season. 



The other field work of the department has progressed satis- 

 factorily. A bulletin on the "Control of the Red Spider in 

 Greenhouses" is now ready for publication. Further work along 

 the line of cultural methods of control is planned. 



The experiments on the study of the causes of foliage injury 

 from spraying with pure insecticides have been completed, and 

 have progressed well with the use of the commercial materials. 



The work on the control of the onion fly was checked some- 

 what during the past season because of an absence of the insects 

 in the experimental plots and the immediate neighborhood. 



Nearly all of the other lines of work are well along toward 

 completion. 



