94 



efforts to develop tlie efficiency of dust si:Jrays for apple 

 scab will succeed, as any enconomy of time or reduction of 

 expense in this particular would permit of greater attention 

 to certain injurious insects wiiich need more serious con- 

 sideration. (Appla\ise). 



At the conclusion of Prof. Parrott's address, a photo- 

 graph of the audience was taken. 



THE ClIAIRMi^N: I hope this break in the proceedings 

 will not interfere with the questions. 



MR. WASHBURN: I would like to ask whether one 

 s;praying for plant lice was sufficient or whether additional 

 spraying's during the season are required? 



PROF. PARROTT : As I stated in my talk, there are 

 three species of plant lice that appear on apple foliage and 

 fruit, the oat aphis, the green ajohis and the rosy aphis. If 

 the speaker had in mind the rosy aphis, we believe that the 

 one application, when the buds are breaking, is the import- 

 ant treatment. Now, owing to the fact that the leaves are 

 being curled by this species even before the opening of the 

 blossoms, we are not certain as to the benefit derived by a 

 supplementary treatment. To the solution of that point we 

 shall devote considerable attention from now on. From 

 our studies of the habits of the insect, if a supplementary 

 spraying is given, the application should be made before the 

 blossoms open. 



MR. WASHBURN : Does it apply also to the green aphis 

 as well as the rosy aphis, or not so much? 



PROF. PARROTT: The spraying of the opening buds 

 pffords protection from all three species. Owing to the fact 

 that the green aphis works the entire season on apple trees, 

 it frequently happens in the case of nursery trees, or young 

 apples, that it develops in injurious numbers during July 

 or August. In that case I would spray again as soon as I 

 noticed the insects in injurious numbers, because it is a 

 question of protecting the foliage and terminal growth. 

 I'he importance of spraying early for the rosy aphis is to 



