Two Grap: Pests. 133 



and their grubs later, is a new and very alarming fact. For it means 

 that the best-cared-for vineyards are constantly menaced by neigh- 

 boring infested vineyards where no fight is being made against the 

 pest. 



Many of the grubs were foimd on the roots of the vines in our 

 experimental vineyard in the fall of 1903, and the next June 15 pupse 

 were hoed out from beneath some vines. Thus the vineyard was 

 well infested by the insect, and as the vines were very thrifty and in 

 heavy foliage during the season, the conditions were ideal and seemed 

 to meet the objections made against our previous year's work. 



The first root-worm beetle was seen in the experimental vine- 

 yard on Jime 23, and spraying was begun two days later, or on 

 nearly the same date as in 1903. Six rows of vines through 

 the center were left unsprayed for a check experiment, and the 

 remainder of the vineyard on one side the check rows was 

 sprayed with arsenate of lead, and on the other side this poison 

 was used with Bordeaux mixture. Four pounds of the poison 

 was used in fifty gallons of water or Bordeaux mixture. The 

 first spraying was finished on July 2, and on July 11 and 12 

 the vines were again sprayed with the same mixtures. The work 

 was thoroughly done by the jimior author, who is an expert in this 

 kind of work. Part of the first spraying was done with a hand-power, 

 horizontal pump on a large tank (Fig. 28), and the remainder of 

 the work was done with a carbonic-acid gas sprayer (Fig. 28), which 

 thoroughly sprayed in one day seven and one-quarter acres. The 

 total cost of the first spraying on eight and one-quarter acres was 

 $39.10, and 1,500 gallons of poison was used. The second application 

 cost only $23.15 to apply 1,000 gallons of poison. This difference in 

 cost was due to the more rapid but equally as thorough work with the 

 carbonic-acid gas-power machine that required the services of but 

 two men, one to drive and one to attend the fixed nozzles. The gas- 

 power pump with its higher pressure gave a finer spray, and thus used 

 less of the poisonous mixture in the second spraying. With proper 

 apparatus, vineyards can be sprayed thoroughly and effectively for 

 the root-worm beetles at the rate of six to eight acres a day for not 

 over $3 an acre for each application. 



Results of spraying experiments in 1904. — Soon after the second 

 application of poison on the experimental vineyard, it was very 

 evident that the foliage on the sprayed vines was being much less 

 eaten by the beetles than on the check rows. On July 21, the junior 

 author applied our decisive test by counting the egg masses on 15 

 vines in the sprayed sections each side of the check rows, and then 

 on 15 unsprayed vines, with the following results: 



