80 THE REPORT OF THE No. 19 



hatched gives better results. Whitewash applied twice in the autumn after 

 the leaves have fallen is said to be an excellent and cheap remedy. 



The Nev^ York Plum Scale. 



All the scales of this species which were covered with the spray were 

 killed and shrivelled up. As these insects hibernate chiefly on th.e underside 

 of branches and twigs and are sometimes found in great abundance on this 

 part of the lowest branches, great care should be taken to see that the spray 

 is forced up through the tree from beneath as well as driven in from the 

 side or allowed to fall upon the branches from above. 



The Pear-tree Psylla. 



I asked the opinion of those farmers who have tested tbe effect of tbis 

 wash upon the Pear-tree Psylla. The most definite information I got on the 

 subject was from Mr. E. M. Smith, of Winona. Mr. Smith was one of 

 the first men in the district to begin using lime-sulphur. It occurred to 

 him one year that the wash might destroy the Psylla, so he made a special 

 test. A certain plot of pear trees were sprayed with lime-sulpliur, and an- 

 other plot equally bad with the Psylla was left unsprayed. Tbe result was 

 such as to convince him most strongly that the wash would destroy this in- 

 sect. 



Aphids. 



Whether the lime-sulphur will destroy aphids' eggs and thus control 

 the aphid pest is a much disputed question. Some of the fruit-growers think 

 it will, others think not, but none whom I met could give definite informa- 

 tion. In some of my own experiments this year the apbids had already 

 batched and were on the ends of the opening buds; some also had worked 

 their way in among the tiny bud leaflets. About 50 per cent., as nearly as 

 I could tell, were destroyed by the wash. Only those died that the spray had 

 actually fallen upon. Those that were in among the leaflets of the bud 

 were of course safe, and in spite of the most careful spraying some of the 

 others failed to be hit. On trees that had been sprayed before the hatching 

 of the eggs, I found it impossible to determine the effect on the eggs simply 

 because there were scarcely any eggs to be found. In order to test this point 

 better, a tree with numerous eggs on the twigs was sprayed this autumn on 

 November 23rd, but it is not possible to determine the results in time for this 

 paper. A number of good entomologists tell us that tbe wash does destroy 

 "the aphid eggs. Every one should test this for himself, and if it prove 

 to be true in our climate as well as in the United States, it will be another 

 ■strong argument in favor of using lime-sulpliur. 



The Bud Moth. 



The part of the orchard which I sprayed in May was the part where the 

 Bud Moths were worst. So far as I could see from comparing sprayed and 

 unsprayed trees very few of these insects were killed. It is probable that 

 all the larvse were already out of their winter cases and were in the bursting 

 buds and so escaped the spray. There is need of further experiments to 

 determine the effect upon this pest. 



The Codling Worm. 



As a result of spraying with Paris green there are very few Codling 

 •worms in the College orchard ; hence I could not determine the effect of the 



