242 



INTERNATIONAL CONGRESS OF VITICULTURE 



abundant the foliage in the fall presents a specked appearance that is very 

 noticeable. 



A few individuals of the hibernating brood of beetles live and remain 

 upon the vines until as late in the season as the first of October. Most of 

 the beetles, however, that are to be seen on the vines during the fall months 

 belong to a new brood that begins to appear in July. These young beetles 

 may be distinguished for a while from those of the old brood by their 

 darker color and fresh appearance. They feed freely on the foliage and 

 deposit a few eggs which are mostly infertile. 



With the coming of cold weather they leave the vines and hibernate, 

 probably under objects of various kinds that they may find scattered on the 

 ground. It is possible a few beetles remain in the cocoon over winter and 

 emerge in the spring. As previously stated, the beetles reappear on the vines 

 during the month of May, or, at about the time grape vines are in bloom. 



Natural Enemies. 



Two hymenopterous parasites, Bracon mellitor Say and Stiboscopus 

 brooksi Ashm., commonly attack the grape curculio. The former destroys 

 the larva while in the grape and the latter attacks and devours the larva or 

 pupa while in the cocoon. Ants and other predacious insects destroy many 

 of the larvae, especially at the time they are leaving the fruit to pupate. 



Methods of Control. 



As has already been suggested, the application of arsenical poisons to the 

 foliage of the grape is an effective method of destroying the adult grape 

 curculio. The most satisfactory time to apply the poison is in the spring 



Fig. 8. Grapes protected by paper bags. 



