CONTROL OF THE GEAPE-BERRY MOTH. 39 



mally necessary. These figures do not include interest on money 

 invested in the spraying machine, depreciation, breakage, or inci- 

 dental costs of operation, such as gasoline and oil, since these vary 

 greatly. The details of cost for a single application are as follows: 



Materials for 150 gallons of spray mixture: 



Arsenate of lead (paste), 9 pounds, 8 cents per pound $0. 72 



Lime, 3 pounds, J cent per pound ! 01 



Resin fish-oil soap, 3 pounds, Q\ cents per pound . . . 19 



Labor, 3 men, \ day at $2 per day 1. 00 



1 team, £ day, at $3 per day 50 



2.42 

 For the two applications the cost would be $4.84 per acre. 



The entire cost, however, need not be charged to berry-moth con- 

 trol if a combination spray is used. These two spray applications 

 are necessary in the majority of vineyards to secure the greatest 

 possible profits, even if the berry moth is not present. In a vineyard 

 where control measures are already employed against the rootworm, 

 leafhopper, and powdery mildew, the additional cost per acre in 

 controlling the berry moth would be as follows: 



Extra cost of labor for using ' ' trailers ' ' instead of ' ' set nozzles ' ' in the first 

 application. 



Labor cost with ' ' trailers " (see above) $1. 50 



Labor cost with "set nozzles," 1 man and team \ day at $5 per 



day 675 



$0. 825 



Arsenate of lead (paste), 9 pounds for second application, at 8 cents per 



pound 72 



Soap, 6 pounds (2 applications), at 6J cents per pounds 375 



Total 1. 920 



Thus, if spraying for rootworm, leafhopper, and mildew is properly 

 done the extra cost of spraying for the grape-berry moth is only 

 $1.92 per acre. 



SUMMARY AND RECOMMENDATIONS. 



The grape-berry moth can be controlled by spraying. Other 

 methods will reduce berry-moth infestation, and some of them can 

 be employed profitably to increase the efficiency of spraying, but 

 none offers a dependable control in commercial vineyards. 



Gathering and destroying grape leaves hi the fall is of little use in 

 berry-moth control. 



Bagging grape clusters immediately after the setting of the fruit 

 will exclude the berry moth and prevent infestation, but the expense 

 is prohibitive in commercial vineyards in this region and may be 

 used advantageously only in garden vineyards. Hand picking of 

 grape berries infested by first-brood larvse, if done by competent labor, 

 will reduce berry-moth infestation, but except in extraordinary cases 



