9S 



advise a pear grower who is seriously troubled Avith the pear 

 psylla, to make every year. 



A MEMBER: I don't know what the psylla fly leotj:;) 

 like. 



PROF. PARROTT : A great many of our pear growers 

 iii New York are having the same trouble, but just as it is 

 with aphides, so it is with the pear psjdla, efficient control 

 depends more on knowledge of habits of inseets> than on a 

 choice of spraying mixtures. I do not l)elieve any pear 

 grower or any apple groAver will ever control pear psylla or 

 aphides unless he grasps thoroughly the whys and AVhere- 

 tores of the treatments. If a man does not know the p.sylli 

 t^y, does not recognize it when it appears on the tree and i,^ 

 not able to judge the exact conditions for making the treat- 

 ment, then certainly he is seriously handicapped as far as 

 effective spraying work against such a pest is concerned. 



A MEMBER: No matter how thoroughly I spray, if I 

 have got a neighbor who does not spray, there are enough 

 insects over from his trees to re-infest mine. 



PROF. PARROTT: That is a serious difficulty and is 

 one of our great problems in western New York, especially 

 ].i the region near the Niagara River, where extensive 

 plantings adjoin each other. All you can do under those 

 circumstances is to encourage co-operative spraying. I do 

 indeed feel sorry for the owner of a pear orchard who ha* 

 neighbors that pay no attention to spraying and neglect 

 iheir trees with respects to the pear psylla. 



MR. PERKINS: I would like to ask if soluble sulphur 

 is a substitute for lime-sulphur under those conditions? 

 Also if you use Black Leaf 40 with arsenate of lead? 



PROF. PARROTT: Are you referring to spraying for 

 aphides or to treatments for the pear psylla? 



MR. PERKINS: Well, both the Black Leaf 40 in cou- 

 liection with the aphis and the soluble sulphur. in connec- 

 tion with the psylla. 



PROF. PARROTT: This soluble sulphur is not a lime- 

 sulphur preparation but is a sodium sulphide. As I said in 



