REPORT OF THE HORTICULTURIST 131 



SESSIONAL PAPER No. 16 



much greater strength than is necessary to kill the beetle, but they desire to kill them 

 quickly. Sometimes so much Paris green is used that it injures the leaves. Arsenate 

 of lead, while it does not seem to kill quite as quickly as Paris green, adheres to the 

 foliage much better, hence is especially valuable in showery weather. It has been 

 found that a mixture of Paris green and Arsenate of lead gives good results, as shown 

 in the following table. This gives the quick action of the Paris green with the 

 adhesive qualities of the Arsenate of lead. Two pounds of Arsenate of lead alone to 

 40 gallons water are shown by this experiment not to be sufficient to kill the beetle 

 promptly; from 2£ to 3 lbs. are necessary. It will be seen that Bordeaux mixture, 

 applied with either Paris green or Arsenate of lead, makes these insecticides more 

 effective. This is, no doubt, partly due to the adhesive properties of the Bordeaux, 

 which cause the insecticides to remain longer on the plants. 



16—9* 



