174 THE UBPOPtT OF THE No. 36 



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wide open, and are sought by the majority of the young larvse in preference to open 

 leaves. The undeveloped fruit buds are also sought. (2) When the larvae become 

 large they seem to be very little affected by the poison. We found many well 

 poisoned leaves being eaten and the larvae perfectly healthy. 



That the poison will kill the younger larvae if they eat it was proved by 

 Mr. Crawford by immersing infested twigs in various strengths of arsenate of lead 

 in water. He used 2, 3, 4 and 5 lbs. to 40 gals, of water respectively, and killed 

 all larv£e with each strength except those in the undeveloped leaves that were 

 so closely folded that the liquid did not get in. It entered all loosely rolled 

 leaves. This sort of dipping, however, is very different from the very best spraying 

 even with power machines that can be done, especially on large trees, because the 

 spray fails to get into many a loosely rolled leaf, or mass of ])lossom clusters or 

 leaves webbed together. 



Unfortunately, I was too busy conducting spraying experiments for San 

 Jose Scale, Canker Worms, Codling Moth and Apple Scab in an orchard in the 

 Niagara district to do the spraying myself at Simcoe, and Mr. Crawford was too 

 busy watching the three Leaf-rollers and the Capsid to devote much of his time to 

 it. Mr. Johnson, however, had a good outfit and certainly sprayed more thoroughly 

 than most men would do. He was just as eager to kill these insects as we were. 

 Pour applications with double strength arsenate of lead (almost 4 lbs. to 40 gals, of 

 dilute lime-sulphur) were used. The first was just as the leaflets began to appear, 

 the second just before the blossoms opened, the third as soon as the blossoms 

 fell, and the last two weeks later. Black-leaf-40 was used at his own desire with 

 the last of these to destroy Aphids. The foliage showed whitish all summer long 

 with these heavy sprayings. 



Mr. Sexsmith, of Trenton, on my advice also sprayed his orchard very 

 heavily before the blossoms opened and used double strength arsenate of lead. 

 He also sprayed heavily for the Codling Moth. Yet in both orchards the results 

 were very disappointing for there were numerous larvie left and many observations 

 in the former by Mr. Crawford and myself convinced us that only a small per- 

 centage .of the larvae had been poisoned. I intend, however, to re-test this next 

 year and supervise all the spraying myself. 



Black-Leaf-40, it is claimed by some, will control this pest if applied while 

 they are young. Gill, of Washington Bureau, tested this but did not get so good 

 results as from arsenate of lead alone. It certainly had no lasting effect upon 

 the medium sized larvae at Simcoe, though for a little while it seemed to .stupify 

 some of them. It doubtless would help in the spray just before the blossoms 

 burst, but would not kill the larvae in the closely folded leaves and buds. It 

 seems to me we could not possibly hope to get satisfactory results from it even 

 with two applications. It is, moreover, very costly. 



Lime-sulphur is known to be useless against the eggs. 



Miscible oils alone have given really satisfactory results to most investigators. 

 This spray is used only against the eggs. 



I sent Mr. Johnson ten gallons of Scalecide and instructed him to dilute 

 this 1 to 5 and to spray just as the buds were ready to burst. He was told to 

 centre his spraying on the twigs of the infested Spys and pay no attention to the 

 bare branches and trunk. He did so and used about from 4 to 5 gals, to a tree 

 One Baldwin tree he sprayed heavily. The result was that this tree showed 

 approximately 80 per cent, of unhatched eggs, unsprayed trees only about 2 per 

 cent., and the lightly sprayed Spy trees not more than from 10 to 25 per cent. 

 The explanation, however, of the poor result is simple but very instructive. 



