502 



BULLETIN 333 



of the beetles appear. The beetles come from their winter hibernating 

 places in early spring as the leaves are beginning to push out, and in a 

 few days they begin to eat holes in the leaves (Fig. 172). This is the time 

 when the first spraying should be done. 



This time will vary with the earliness or lateness of the season. In 

 1911 the first spraying was begun on May 16, while in 1912 spraying was 

 not begun until June 13. This, however, was a few days later than 

 the work would have been begun had it been purposed to make two appli- 

 cations. In making the first application no particular attention need be 



paid to coating the undersides of the leaves, 

 since the beetles eat holes entirely through the 

 foliage. 



The second spraying should be done as the 

 eggs begin to hatch, which will be about three 

 weeks after the first application. In 1911 the 

 second spraying was begun nearly four weeks 

 after the first, but probably it should have 

 been begun somewhat earlier. In making this 

 application special pains should be taken to 

 coat the undersides of the leaves. The grubs of 

 the beetle work on the lower sides of the leaves 

 almost entirely, and in order to kill the insects 

 before they have done serious injury the poison 

 should be on the underside. 



The first injury noticed by the grubs is likely 

 to be in the tops of the trees, although the 

 grubs have been seen seemingly as abundant 

 and injurious on the lower branches as higher 

 ^ Never theless, the writer would emphasize 

 the importance of reaching the topmost branches 

 with the spray. If a few grubs are left in these branches they will 

 eventually transform and furnish a crop of adult beetles for succeeding 

 years. 



The writer would also emphasize the necessity of spraying early for 

 beetles and for grubs. If the beetles or a large percentage of them are 

 killed, not many eggs will be deposited; while the grubs are much more 

 easily killed when young than when two thirds or three fourths grown. 



AMOUNT OF POISON TO USE AND NUMBER OF TIMES TO SPRAY 



As already stated, the trees were sprayed twice during the first season 

 of the work and the -mixture used was 3 pounds and 3^ pounds, respectively, 

 of paste arsenate of lead to 50 gallons of water. The brand of arsenate 



FlG * I2 ' 



""*"* 



