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INTERNATIONAL CONGRESS OF VITICULTURE 



Fig. 1. Larvae feeding on foliage. 



they resume feeding. At such times they travel a distance, usually with the 

 wind, and upon entering a vineyard begin feeding on the swelling buds of the 

 grape, eating holes in them (Pig. 2b). 



They tear off small areas of the bud scales and eat. into the green por- 

 tion of the bud, tearing the tissues with their mandibles. The circular hole 

 results from the insect eating all the food it can reach without removing any 

 more of the dry bud scales and continuing this process until the interior of 

 the bud is often entirely eaten. The more common effect of feeding is to eat 

 to the center of the bud. By this time the appetitie is satisfied, for a short 

 period at least, and the beetle moves elsewhere. Such injured buds never 

 develop and the crop of grapes, which normally would have developed from 

 them, is destroyed. Later from beneath these buds, new ones usually develop 

 but these seldom, if ever, produce fruit. On severely infested vines, often 

 every bud is destroyed. In fact, we have seen several hundred vines thus 

 injured. Of the 4,020 vines in this vineyard, 1,048 vines escaped injury, but 

 56 per cent of the fruit was ruined in the buds, making a monetary loss of 

 $220.00. When the buds which remain uninjured have opened, the beetles 



