REPORT OP COMMITTEE ON PUBLICATION 241 



noticed by a casual observer, even where they are abundant. They spend 

 much of their time feeding or resting upon the upper surface of the grape 

 leaves and it is in this position that they may be observed most readily. 



I 



Fig. 6. Adult (x!2). 



They are quite shy and when disturbed are apt to leap vigorously and take 

 wing before alighting. When captured and confined closely in the hand, they 

 gives forth a distinct squeaking sound, a peculiarity which sometimes serves 

 to distinguish the beetle from a lump of clay or a pellet of excrement dropped 

 by a large caterpillar. 



Fig. 7. Adults depositing eggs. 



The beetles feed freely upon the upper surface of the leaves and 

 the bark of the fruit stems. The female, also, devours the tissues removed 

 from the fruit in excavating her egg-chamber. In feeding on the foliage only 

 the green, upper layer of the leaf is removed. The mark on the leaf made 

 in feeding is somewhat circular in form and is composed of distinctive zig- 

 zag lines with minute transverse ridges. The spots vary in size and shape 

 but average about one-tenth of an inch in diameter. From the practical 

 standpoint of the vineyardist, the habit of feeding on the foliage is of great 

 importance, since it makes it possible to destroy the beetles very readily by 

 spraying the vines with arsenicals. 



The beetles issue from hibernation in the spring several weeks before 

 egg-laying begins. They are rather inactive when they first appear but food 

 is taken from the leaves about as soon as they ascend the vines. Thereafter, 

 throughout the season, the peculiar feeding marks on the upper surface of 

 the leaves increase in numbers and conspicuousness. Where the insects are 



