REPORT OF THE SOCIETY 35 



For at the time the last eggs are hatching the lice which have emerged 

 earlier are nearly full grown and well concealed among the protecting hairs 

 within the opening leaf and flower buds. However, can a spray be so 

 applied as to destroy 90% to 95% of the stem mothers and is this sufficient 

 to effectually prevent any serious damage? To this question a positive 

 answer cannot be given at present, but data can be presented showing 

 that it may prove feasible. 



From our studies we have shown that practically all the eggs hatch 

 within the first four or five days after hatching begins. During this time 

 the buds have not opened to any considerable extent, the first leaves to 

 appear being about the size of a dime and offering no considerable place 

 for the concealment and protection of the lice. Can, therefore, the dormant 

 spray be delayed to this time with safety and at the same time a material 

 be added which will destroy the lice? This I think can be done with safety 

 and our data seem to show that the lice can be controlled by such a spray. 

 However, if a dormant spray is not required the application of the contact 

 insecticide can be delayed a day or two provided the work can be accom- 

 plished before the buds have opened too much. 



Experiments. 



Through the kindness of the Department of Pomology permission 

 was obtained to study the results of a dormant spray applied at the time 

 the lice were congregated on the opening buds. The orchard is an old one 

 consisting of tall, straggling trees of many varieties, some of which are very 

 susceptible to aphis injury. The spray was applied by an old machine 

 giving only about 100 pounds pressure. As a very high wind was blowing 

 all the trees were sprayed on one side only, so I had an excellent opportunity 

 to determine the exact effect of the spray. The trees were all badly infested, 

 the grain aphis (Aphis avenae, Fabr.) being especially abundant. From a 

 count of forty buds taken at random the number of lice per bud varied 

 from 5 to 65 with an average of over 13. This was on April 22, 1915, the 

 day on which the spray was applied. The sprays applied consisted of 

 lime-sulphur (1 to 8) and "Black Leaf 40" tobacco extract M pt., 1 pt. 

 and l34 pts. to 100 gallons of the spray mixture. 



On April 30 a close examination was made of the sprayed trees. The 

 side of the trees which had been sprayed showed rather effective control 

 though all the lice were not killed. The following counts of lice on buds 



