REMEDIAL MEASURES. 59 



outright in a single season, while the rest were so weakened that they 

 had to be cut back so severely that in the following season they were 

 unable to produce more than from 15 to 25 per cent of a normal 

 crop. Persons not thoroughly familiar with the habits of the pest 

 have frequently charged this death and weakened condition to a 

 variety of causes, such as winter killing, deep plowing, overbearing 

 of young vines, etc. In practically every case of this kind coming 

 under our observation we have found overwhelming evidence of 

 injury wrought upon the roots by the larvae of this pest. There is 

 no doubt that the overbearing of young vines which possess a limited 

 root system and then become subject to a heavy infestation of grape 

 root-worm larvae will serve to greatly weaken the vine, and that 

 severe winter weather following this heavy infestation of larvae, and 

 consequent weakening of the vine, will accelerate the death of the 

 vine during the winter. Yet these are but secondary evils to which 

 the vines, primarily weakened by injury from the insect during the 

 growing season, finally succumb. This is also true of drought condi- 

 tions occurring in August and September. During the drought 

 which occurred in these months in 1906 numerous cases came under 

 our notice where young vines bearing a heavy crop of fruit and having 

 made a heavy growth of vine early in the season were so badly 

 injured by larvae hatching from eggs deposited in July that they 

 were unable to mature the fruit, which actually shriveled on the vine 

 by the last week in August. Other injured vines which carried 

 through their crop died during the following winter. It is the rapid 

 decline in yield of large numbers of vines in young vineyards through- 

 out the whole grape belt and the steady though less perceptible 

 shrinkage in yield of the other vineyards that make it impossible 

 for the increased planting of recent years to more than hold its own 

 with the crop production of the period previous to the general infes- 

 tation of vineyards by this pest, and it will require the greatest care 

 and watchfulness on the part of those planting new vineyards to 

 carry their young bearing vines through that critical period when 

 they are producing their first two or three crops and at the same 

 time establishing a root system sufficient to continue the production 

 of successive profitable crops. 



REMEDIAL MEASURES FOR THE CONTROL OF THE GRAPE ROOT- 

 WORM. 



EVOLUTION OF PREVENTIVE MEASURES. 



Although the occurrence of this insect in numbers sufficient to 

 cause great damage to the foliage of grapevines was brought to the 

 attention of Walsh in 1866, no remedial measures were suggested by 

 him. The first record of an attempt to control the pest was made 



