40 Farmers’ Bulletin 1220. 
INSECTS AFFECTING THE ROOTS. 
THE GRAPE ROOTWORM.”* 
The grape rootworm, as the name indicates, infests the roots of 
the grape, devouring more or less completely the small roots and 
rootlets and eating 
pits and burrows 
into the outer por- 
tion of the larger 
roots: It is. the 
larva of a _ small, 
hairy, chestnut- 
brown beetle (fig. 
42) which makes 
its appearance in 
vineyards at about 
the close of the 
blooming period of 
such varieties of 
grapes as Concord, 
Niagara, Catawba, 
etc. The beetles 
feed freely on the 
upper surface of 
the leaves, eating 
a series of patches or holes through to the lower surface, thus pro- 
ducing characteristic chain-like feeding marks, as shown in figure 43, 
by which their presence in vine- 
yards can be readily detected. The 
injury to the foliage, however, is 
quite unimportant compared to the 
work of the larve on the roots (fig. 
44). When the larve or grubs are 
abundant the vines may be killed 
in the course of two or three sea- 
sons, but usually the plants will 
linger, though making but a feeble 
growth and failing to produce 
profitable crops. The death of 
vines or gradual failure of a vine- 
rard should call for an examina- [!6. 42.—The beetle or parent of the grape 
Ke 3 y a rootworm. Considerably enlarged. 
tion in late spring of the foliage 
for the characteristic feeding marks of the beetle, and of the roots for 
the work of the larve on these parts. 
The insect is a native species, feeding originally on wild grapes, 
as it does at the present time. In addition to wild and cultivated 
Fig. 41.—Grape cane-girdler and its injury to grape shoot. 
% Fidia viticida Walsh. 
