KECOMMENDATIONS. 91 



When pupae are discovered, the soil beneath the trelHs should be 

 removed by the horse hoe and the soil directly around the base of 

 the vine carefully and thoroughly stirred with a hand hoe. The 

 efficiency of this method of destroying the pupae may be increased 

 by throwing up a ridge of earth beneath the trellis during the last 

 cultivation of the preceding summer. This will tend to encourage 

 the insects to form their pupal cells above the roots of the vine and 

 thus admit of their destruction by cultivation without serious injury 

 to the roots of the vine by the horse hoe. 



It is in these two stages — namely, the pupa and the beetle — that 

 the insect appears to be most readily overcome; in fact, no effective 

 measures have yet been developed for the destruction of the larvae 

 or of the eggs. Experiments conducted against the larvae in the 

 soil with oils, carbon bisulphid, fertilizers, salt, etc., have proved 

 ineffective, and in some cases injurious to the grapevine; and since 

 the eggs are deposited beneath the bark of the canes when the vines 

 are in full foliage, it is practically impossible to reach them with a 

 spray application. 



GENERAL TREATMENT OF INFESTED VINEYARDS. 



In addition to these recommendations dealing with direct means 

 of controlling the insect in producing vineyards, a few suggestions 

 are offered concerning the care and treatment of newly planted 

 vines, and also of old, run-down vineyards in relation to this insect 

 problem. 



Serious injury is most likely to occur to young vines planted in 

 soil on which infested vines were growing during the preceding 

 season, for this soil is likely to be heavily infested with grape root- 

 worm larvae which will transform to beetles. These emerging 

 beetles readily discover the newly planted vines and soon riddle the 

 leaves of these small plants. For this reason it is very desirable, 

 when the replanting of an old vineyard area is found necessary, that 

 some annual crop be grown for at least one season, in order that the 

 soil may be free of the insect when the new vines are planted. 



In order that newly planted vines may be maintained in a thrifty 

 condition during the period between planting and the bearing of the 

 first crop of fruit, the vineyardist should keep a sharp watch during 

 the month of July for the appearance of the grape root-worm beetles 

 upon his young vines. When the beetles are numerous, they skele- 

 tonize many of the leaves, and this greatly retards the growth of the 

 plant. If the infested vines are thoroughly sprayed with arsenate of 

 lead at a strength of 3 pounds to 50 gallons of water, the injury by the 

 beetles may be in a great measure prevented. 



