146 



combination that will kill the aphis without injuring thb 

 leaf to any extent, it is likely to injure the tip. Of course, 

 you have a very short time to do that in. If you have very 

 much spraying to do you will get caught. 



MR. WILFRID WHEELER: It seems to me there is one 

 question we haven't considered in this matter of the aphis, 

 and that is the presence of the parasite early in the spring. 

 Most of us know that the lady beetle is very destructive to 

 the aphis, and if we can determine that they are presenx 

 early in the spring, we can save considerable spraying for 

 the aphis, because the lady beetles Avill take care of it. The 

 lady beetle appears just about as soon as the ground thaws 

 out and we can determine their presence by examining the 

 ground around the base of the tree. If the trees are in sod 

 we will be more apt to find them than in cultivated land, but 

 1 think this should be looked into pretty carefully before do- 

 mg any spraying just before the blossoms open. The lady 

 beetles get in their work early, and eat the eggs as well as 

 the aphis themselves. Possibly if the lady beetle could be 

 jjropagated and held over winter in some safe place, it would 

 1)e an easy matter to take care of the aphis in the spring. I 

 think the experiement stations ought to do a little more work 

 en the parasite question, and perhaps save the expense of 

 spraying which has to be. done with conditions as they now 

 are. 



THE PRESIDENT : Can you give us an idea how many 

 lady beetles you ought to find before you decide it is not 

 necessarj^ to spray"' 



]\IR. WHEELER : Well, I had a tree that was ten years 

 old, covered with aphis eggs as thick as they could stick on 

 it, and while I couldn't find more than a dozen lady beetles, 

 (there may have been more) I know they took care of that 

 aphis crop. They don 't eat the entire egg ; they just punc- 

 ture it and suck the juice and that finishes the egg. The 

 same way with the msect, they puncture it and take the 

 juice. I don 't think it would require a great many. 



QUESTION: How about the pear psylla? I have got 



