GRAPEVINE ROOT WORM 41 



period when beetles were to be found in cages, failed to disclose 

 any substantial difference between the insects on the poisoned 

 vines and those on the untreated ones. These cage experiments 

 were further supplemented, as detailed on page 29, by exten- 

 sive spraying. This was done June 25, and July 1 no dif- 

 ference could be detected between the sprayed and the un- 

 sprayed vines. This, in connection with our cage experiments, 

 led us to abandon reluctantly further outdoor tests, and the 

 poisoned areas were collected over in order to prevent what we 

 deemed would be an extensive deposition of eggs. In other words, 

 no experiments, other than those confined to small tumblers where 

 the beetles could obtain absolutely nothing except poisoned 

 foliage, gave results which are at all decisive. The reasons for 

 this are several: the beetles do not succumb readily to poison, 

 and being more or less secretive by nature, feed to a considerable 

 extent on under leaves and in concealed situations where it is 

 difficult to throw the spray. In addition they have a marked 

 tendency to feed on the more tender leaves, which at the time 

 spraying should be done appear almost daily on vigorous vines. 

 These factors make it very difficult to control the insect. 



The most decisive results obtained with an arsenical spray are 

 those published by Mr John W. Spencer of Westfield, in the 

 issue of the Grape Belt for July 24, 1903, in which he gives some 

 definite figures in favor of spraying. Our only regret in this 

 connection is that his experiments were not conducted on rapidly 

 growing vines, because in our judgment these need protection 

 much more than those in poor condition and on which the insects, 

 as previously pointed out, can not be controlled nearly so 

 readily. 



Several vineyardists sprayed their vines in 1903 for the pur- 

 pose of controlling this insect, and as it was stated by various 

 growers that the poison applications had been successful, at their 

 request these vineyards were inspected by us the first week in 

 October, and much to our regret, we found that the reported good 

 results were more apparent than real. 



An examination in the vineyard of Mr Frank Monfort, of Broc- 

 ton, resulted in finding 5, 45, 10 and 9 grubs respectively under 

 as many Concord vines. The first record relates to a 



