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injured by the weevils that it was difficult later to see that any good had 

 been done by the spray; but the following spring, after the adults had 

 emerged from their winter quarters, the number of weevils was very 

 noticeably smaller in the sprayed orchard. To determine definitely the 

 difference in numbers in the two orchards, counts were made 

 from a large number of buds on trees in adjoining rows in the two or- 

 chards, and in each orchard on the third and fifth rows from these 

 adjoining rows. In the sprayed orchard 329 weevils were found on 

 4800 buds, and in the unsprayed orchard 1052 weevils on the same num- 

 ber. Thus over two-thirds of the weevil population was destroyed in the 

 sprayed orchard. Had the spray been applied two weeks earlier, no 

 doubt much injury to the foliage would have been prevented, and in all 

 probability the reduction of infestation the following year would have 

 been equally great. 



Summary on summer spraying ivith arsenicals. — In brief, the gen- 

 eral conclusions which may be drawn from tlje summer application of 

 arsenicals and arsenicals in combination with fungicides are as follows: 



In all of the trials save one, a decided repellent effect was obtained 

 when either lime-sulfur or Bordeaux mixture was used in connection 

 with the arsenical, and in this one exception a kill was obtained equal to 

 that following the use of arsenicals alone. In every instance where 

 arsenicals were applied, some killing resulted, but it is an open question 

 whether the percentage of beetles killed or repelled warranted the cost 

 of the extra application. The kind of application required, that is, 

 spraying the under side of the leaves, is wasteful of both material and 

 labor, and is therefore more expensive than the usual application in 

 which no effort is made to cover anything but the upper surface. The 

 only occasion in which extra summer applications of arsenicals might 

 possibly prove profitable would be in excessively severe outbreaks where 

 a partial control might prevent extreme weakening of the trees. 



SUMMER APPLICATIONS OF CONTACT INSECTICIDES 



Our experiments with summer contact insecticides were all of a 

 preliminary character and need only be summarized briefly. With the 

 exception of the last named, they were all made in June after consider- 

 able damage had been done by the new brood of adults. The insecticides 

 used, were scalecide, a mixture of scalecide and soluble sulfur, Lasher's 

 soap, black leaf forty, kerosene emulsion, and nicotine dust. Neither of 

 the first two proved effective at strengths which did not injure the 

 foliage. 



Lasher's soap.— Twelve heavily infested trees were sprayed with a 

 solution of Lasher's soap, 10 lbs. to 100 gallons of water. A heavy 

 rain interrupted the work after the tenth tree had been sprayed. Spray- 

 ing the trees causes the weevils to drop, and nearly all were driven from 

 the trees. A canvas, spread under one of the trees before the spraying 



