THE GRAPE-BERRY MOTH. 49 



DEGREE OF VINEYARD INFESTATION IN ERIE COUNTY, PA. 



The infestation of vineyards by this pest is by no means general. 

 It frequently happens that serious infestation will be confined to one 

 or two rows along the edge of a vineyard or running in for a few 

 vines at the end of a number of rows, or again, in an irregular patch 

 at the corner of a vineyard. Usually such areas of very serious 

 infestation are adjoining hedgerows, fences, or bordering rough 

 lands which admit of the accumulation of leaves and trash. On 

 the other hand, the worst infestation over a large area coming under 

 our observation was in a vineyard which was surrounded by neither 

 hedges nor ditches, was a considerable distance from woodlots or 

 rough land, and was subject to clean culture and excellent care. 

 Again, it is not unusual to find a vineyard portions of which have 

 been badly infested for a number of seasons but adjacent vineyards 

 comparatively free from infestation. Because of this seemingly 

 erratic infestation it is exceedingly difficult either to estimate the 

 actual damage wrought by the pest or to secure reliable results for 

 comparison as to the amount of benefit from remedial treatment. 

 Another result of this erratic infestation is that the vineyardist 

 will minimize the extent of the injury or even entirely overlook it 

 until picking time, when he is astonished to discover the large amount 

 of damage that has been done. When this abundant evidence of 

 injury is brought so clearly to his attention at picking time he is 

 likely to make a vow to take some steps toward the eradication of 

 the pest next season, but only too often, unless the first brood is 

 extremely abundant, the period for effective treatment is again per- 

 mitted to slip past and the extent of injury at picking time is likely 

 to be the same as in previous years. An additional result of this 

 somewhat restricted and local infestation is that methods of control 

 of the pest are not so freely discussed among the vineyardists and 

 there is not the impetus of a general effort to effect its control that 

 there is in the endeavor to combat an insect whose injury is more 

 apparent and widespread, as in the case of the grape rootworm and 

 the grape leafhopper. 



The statements dealing with the destructiveness of this insect in 

 the preceding paragraphs apply to the depredations of the pest in 

 the vineyards of the Lake Erie grape belt, where local conditions 

 have been studied closely for several seasons. In the township of 

 North East, Pa., there is an area stretching east of the town to the 

 New York State line and lying south of the Lake Shore Railroad in 

 which are located the vineyards most heavily infested by the grape- 

 berry moth in this region. In the summer of 1906 one large vine- 

 yard was visited in this area in which the infestation was quite gen- 

 eral and on limited portions of it the fruit was almost unmarketable. 



