INSECTS INJURIOUS TO THE GRAPE 445 



Control. Extensive experiments made by several investigators 

 have shown that the beetles may be very largely destroyed by 

 thorough spraying with arsenate of lead just as they appear. 

 By applying the poison when they are first noticed feeding they 

 may be killed off before many of the eggs are laid, and sprayed 

 vineyards have shown a reduction of over 90 per cent of the eggs 

 found on untreated vines. Arsenate of lead should be applied at 

 the rate of 3 pounds to the barrel as soon as feeding marks are 

 found on the foliage, and again a week or ten days later, and 

 should be added to the Bordeaux mixture used for the diseases 

 of the vine. The spraying must be done with the greatest thor- 

 oughness, as the beetles dislike the sprayed foliage and will seek 

 out that which has been 

 missed . The nozzles on trac- 

 tion outfits should therefore 

 be arranged so as to hit all 

 parts of the vines (see Fig. 

 374) and the pump should 

 maintain at least 100 pounds 

 pressure. With the machines 

 in common use not over 7 or 8 

 acres a day may be covered 



thoroughly, and about 125 



.,! , . FIG. 374. A power sprayer with noz- 



gallons will be required per z l e s arranged for grape spraying (The 



acre. If the work is hurried Bean s P ra y Pum P Co -) 

 to cover greater acreage, the treatment will usually be less effec- 

 tive. When the infestation is unusually severe cheap molasses 

 may be added to the arsenate spray to make it attractive to the 

 beetles. 



The beetle is noticeably less destructive in well-cultivated 

 vineyards, and it has been shown that thorough cultivation in 

 early summer breaks up the pupal cells and destroys large num- 

 bers of the pupae. Most of the pupse are within 2 or 3 inches 

 of the surface and within 1J or 2 feet from the base of the vine. 

 In the fall the earth should be thrown toward the vines to form 

 a ridge along the row, so that the larvse will mostly pupate near 

 the surface of this ridge. The next spring, when most of the 

 larvae have entered the pupal stage, this ridge should be thrown 

 away from the vines, thus exposing the pupse. A "horse-hoe" 



