GRAPEVINE ROOT WORM 7 



less wood yearly till finally there is not enough to tie up. A 

 portion of a vineyard very seriously injured and where there is 

 not wood enough to tie up is represented on plate 3. This con- 

 dition rapidly becomes worse, and soon, usually in two or three 

 years after the insect has been present in numbers, there is no 

 wood, and the vines are simply a small mass of foliage resting 

 on an old stump as represented on plate 4. 



The depredations of this pest are much more serious and 

 usually first apparent on light sandy or poor soils, and in particu- 

 lar on gravelly knolls, though we have found the beetles much 

 more abundant in rich, low, though not wet hollows. The insects 

 seem to thrive under such conditions, and a deficient growth 

 should lead to immediate investigation. Vines on rich clay soils 

 in our experience are less injured by this pest, due probably to 

 their greater resistant powers; and this appears to be the case 

 in Ohio. It should be remembered that vineyards on heavy 

 clay lands are not exempt from attack and should be closely 

 watched and, if necessary, active measures employed to keep the 

 number of beetles below the danger point. 



The roots also afford a clue to the identity of the depredator. 

 The young grubs eat away the small feeding branches, while the 

 larger individuals gnaw the bark, particularly from the under- 

 side of the larger roots. They frequently eat away long strips, 

 as represented on plate 1, figure 5, though occasionally a single 

 grub may work along a somewhat sinuous path. 



A native species. This serious pest of the vineyards is not, 

 like many of the forms so injurious to agriculturists, an im- 

 ported insect. It has long been known to occur in this country 

 and its work on wild grapevines was observed before its depre- 

 dations attracted notice in our vineyards. This insect may 

 develop into a general pest of the grape and perhaps in time 

 come to be as well known as the very destructive Colorado 

 potato beetle, which is familiar to almost every farmer. It is 

 very probable that this grape enemy was able to exist only in 

 relatively small numbers on wild vines and hence was rarely 

 very injurious. It seems to have developed a great fondness 

 for some of our cultivated varieties, and the growing of these 

 in large areas has enabled it to increase to an almost unparal- 

 leled degree. This may perhaps be cited as one of the cases 



