REPORT OP COMMITTEE ON PUBLICATION 



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out. If a number of pieces are torn out a chain-like appearance is presented 

 on the upper surface. The feeding on thick leafed varieties usually extends, 

 in depth, only to the small veins near the under surface thus leaving a net- 

 work of veins exposed but as the leaves grow older these veins die and fall 

 out thus leaving an irregular chain-like hole. If the beetles are very numer- 

 ous individual leaves may have the tissue eaten so that only shreds remain, 

 but it is very seldom that sufficient feeding occurs on the foliage of a vine to 

 cause injury. The writer recalls only one such instance. In this case a vine- 

 yard of three acres had the foliage seriously injured. It happened that the 

 owner had had an adjoining vineyard so severely infested by the larvae that 

 the vines were badly injured and this vineyard was pulled out in May. As 

 the larvae had completed feeding this did not effect their development and 

 after emergence the adults concentrated on the nearest vineyard. 



Fig. 2. Effect on roots of severe attack of larvae (reduced). 



The greatest damage by Fidia viticida is caused by the larvae, or, so- 

 called root-worms, feeding on the roots of the grapes. The young larvae feed 

 first upon the small fibrous roots usually eating the bark but as the grubs 

 increase in size they gnaw through the small rootlets and channel the bark 

 of the larger roots, often girdling them. This destruction of the root surface 

 decreases the water and food absorption of the plant thus weakening the 

 same. These channeled roots with a scarcity of fibrous roots is the first 

 sign that a grower should seek in a diagnosis of the cause of weakened 

 vines and the presence of these characters would indicate some species of 

 grape root-worm. There are several species of root-worm attacking grapes 

 in the United States and the correct determination of the species must be 



