46 PROTECTION OF PLAI«^TS, 1920-21 



trees applications of nicotine sulphate gave good results. This operation has 

 perhaps not been put into practice in the case of potatoes, because the special 

 spraying devices have been wanting. 



Bordeaux mixture has not any noticeable action on these insects. In 

 fields of potatoes lad}' bird larvae feeding on the plant lice are developed to a 

 tremendous extent. 



I do not think that we should be very much alarmed over this purely local 

 appearance of these insects : it is well, however, to be acquainted with them so 

 as to be able to take measures to arrest them in case of invasion, which is always 

 possible. 



In looking over the entomological literature of the United States, I note 

 that several states, particularly Maine, have suffered from the potato plant 

 louse. In all cases, the experts recommend applications of nicotine as the most 

 effective, after trying out man}' other treatments. 



I have thought well to note the above facts on account of the economic 

 importance of its knowledge. 



I shall listen to and read with pleasure any suggestions the members of the 

 Society may offer on the subject. 



