216 MANUAL OF AMERICAN GRAPE-GROWING 



In California there is a grape root- worm (Adoxus obscurus) 

 quite distinct from the grape root-worm of eastern America 

 which injures both the roots and the parts of the vine above 

 ground. As in the eastern species, the best evidence of infesta- 

 tion of this pest is the narrow chain-like strips eaten out of the 

 leaves, though the insect also gouges out part of the petioles, 

 pedicels, berries and shoots and works under ground, eating 

 the rootlets and bark of the larger roots. Infested vines 

 show a stunted condition, the canes fail to attain a normal 

 growth and often the vines are killed outright. As in the 

 case of the eastern species, this root-worm is the larva of a 

 beetle, the life history of the insect not being greatly different 

 from that of the eastern beetle. Two methods of control are 

 fairly effective : the adult beetles may be jarred from the 

 vine and captured on a screen when the infestation is restricted 

 to small areas ; or the beetles may be poisoned with the arseni- 

 cal spray recommended for the eastern species. Both jarring and 

 spraying often have to be repeated as new infestations appear. 



The grape leaf-folder (Desmia funeralis) is another insect 

 pest of vineyards in California, and occasionally in the East, 

 which works, however, only in restricted localities and in occa- 

 sional years. In California, the insects are detected in a vine- 

 yard by the characteristic rolling of the leaves in which a tube 

 rather less than the diameter of a lead pencil is formed for 

 the home of the larvae. The larvae feed on the free edge of the 

 leaf in the interior of the roll and are thus protected by the 

 outer layers. In the East the caterpillar merely folds the 

 edges of the leaves together. This leaf -folder hibernates as 

 a chrysalis, coming forth in early spring to lay eggs on the 

 vine shortly after the foliage has appeared. There are two 

 broods in California and the northern states and three broods 

 in the southern states. The leaf-folder is easily disposed of 

 by spraying with an arsenical spray just after the eggs hatch 

 and before the larva is protected by its roll of leaves. 



