REPORT OF THE STATE ENTOMOLOGIST I905 



6l 



others following at intervals of about a week or 10 days. It was 

 stated that the spraying was thorough, though examination leads 

 one to believe that the treatment was concentrated about the mid- 

 dle of the vines for the special purpose of covering the fruit, the 

 lower and upper leaves escaping the application to a considerable 

 extent. The finding of numerous beetles in this vineyard shows 

 that the insects can thrive on sprayed vines and emphasizes the 

 necessity of very thorough work in case one attempts to control 

 them in this manner. The adaptability of beetles to this condition 

 is further demonstrated by finding grubs late in the fall rather 

 abundant under the vines, showing that these insects will select 

 their food whenever there is an opportunity and that they can 

 thrive where other species might succumb readily. 



General summary. The observations of the last few years have 

 brought out certain facts rather conspicuously. 



They have shown first of all that vines growing on heavy clay 

 soils can withstand greater injuries by root worm than those upon 

 light sandy soils. 



They have demonstrated that root worms display a marked pref- 

 erence for the lighter soils, and when vigorous vines are growing 

 thereon the chances of injury are greatly increased. 



Our investigations have shown that this insect is to a consider- 

 able extent a local species ; that is, it may breed in very large num- 

 bers in one vineyard or even in a portion of a vineyard and be 

 almost absent from other parts. The reason for this is sometimes 

 seen in greater thrift of badly infested vines and in other cases no 

 ready explanation can be found for the difference. 



It has been shown that the beetles- fly more or less freely, some- 

 times entering a vineyard in large swarms and depositing a great 

 many eggs. This fact is of considerable importance because a vine- 

 yard free from the pest one season may be very badly infested 

 another. These peculiarities in the behavior of the insect render 

 constant watchfulness necessary on the part of the grower. 



Our experiments with arsenical poisons have not been so suc- 

 cessful as we had hoped, and though the insect is undoubtedly 

 checked thereby to some extent, we doubt the wisdom of relying 

 wholly thereupon. Experience and investigations show that the 

 applications must be exceedingly thorough in order to obtain even 

 a moderate amount of protection in this manner. 



Recommendations. The peculiar and somewhat erratic habits 

 of this insect lead us to emphasize the advisability of watchfulness 



