64 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



EXTENT OF INJURY TO NEWLY BEARING VINEYARDS. 



As an illustration of the extent of injury done by this pest to young 

 vineyards which came under the writer's observation during the past 

 summer, the condition of a block of vineyard gi'owing on a level 

 piece of ground in a clay loam soil near the lake shore may be cited. 

 The vines had borne but three crops, and previous to the attack of 

 the grape root-worm were very thrifty. The original planting con- 

 sisted of 3,234 vines. An examination of the vineyard on June 17, 

 1907, showed that 543 vines had been so badly injured by the grape 

 root-worm that they had to be cut back to the ground ; 897 vines 

 were cut back to the lower wire and bore no fruit that season, and 

 the remaining 1,794 vines were cnt back to one or two canes. This 

 treatment, made necessary by root-worm injury, resulted in a cur- 

 tailment of 75 per cent of the crop. 



Figure 1, Plate VIII, shows the condition of the above-mentioned 

 vineyard September 2, 1907. Figure 2, Plate VIII, shows vines in 

 a younger vineyard only a few yards distant, bearing their first crop 

 of fruit and not yet infested by the grape root-worm. (The owner 

 informed the writer that at the same age the vines shown in figure 1 

 were quite as thrifty as those shown in figure 2.) 



Another 3'oung vineyard, 6 years old, on a loose gravel soil, showed 

 an even worse condition. In one section of 1,620 vines, 485 vines 

 were killed outright in a single season, and nearly all the rest of the 

 vines were so seriously injured that they had to be very severely 

 cut back. The crop record of this vineyard is given below, and shows 

 a decline in crop value, in 1907, of $379.80, or 87.17 per cent less than 

 in 190(). 



Table 1. — Crop record of vineyard injured hij f/rapc roof-worm. 



Figure 1, Plate IX, shows the stunted condition of the vines in 

 the above-mentioned vineyard, as a result of the grape root-worm 

 injury. Figure 2, Plate IX, shows a normally thrifty uninfested 

 vineyard at North East, Pa. It should be stated in addition that 

 both of these injured vineyards had received the best of care, so far 

 as cultivation and general management are concerned, with the ex- 

 ception of spraying the vines to protect them from the beetles, and 

 previous to 190r) both vineyardists were highly j)leased with the 

 vigorous condition of their vines. The illustrations cited above are 



