Insect and Fungous Enemies of the Grape. 48 
either pest is unusually abundant, spray applications should be made 
according to recommendations for that particular insect. 
To offset as much as possible the injury of the grubs to the roots , 
of vines in badly infested vineyards, 
care should be given to adequate cul- 
tivation, fertilization, and pruning. Se- 
verely injured vineyards, by improved 
care in these respects, together with 
spraying, have been brought back to a 
condition of satisfactory productivity in 
two or three seasons. 
THE CALIFORNIA GRAPE ROOTWORM.” 
Another rootworm attacks the grape 
in California in a way very similar 
to its eastern relative, the grape root- 
worm. This insect, though widely dis- 
tributed in the United States, seems 
to confine its attack torvinifera or Euro- 
pean grapes in California. It occurs 
in Europe, Algeria, etc. In parts of 
Europe it is a pest of importance to the 
grape. Fic. 45, 
The remedial measures indicated for 
the control of the grape rootworm are applicable in the case of this 
species. 
Egg mass of grape root- 
worm beetle. 
THE GRAPEVINE ROOT-BORER.” 
Injury by the grapevine root-borer is confined to the roots of the 
grape, in which channels or burrows are eaten, or the roots often 
an inch or more in 
diameter may be gir- 
dled (fig. 47). In se- 
vere cases most of the 
main roots may be sev- 
ered, leaving only a 
stub or mere stump, 
thus greatly reducing 
or destroying the vigor 
and productivity of the 
vines. The insect, so 
far as known, attacks 
the grape exclusively, wild or cultivated. It is inconspicuous in all its 
stages and thus is likely to be overlooked, the attack of larve on 
Fie, 46.—Grubs and pupex of grape rootworm, 
22 Adorus obscurus L. | 7 Memythrus polistiformis Harris. 
