S6o 



The Canadian Horticulturist. 



SOME INJURIOUS GRAPE INSECTS. 



MONG those which appear somewhat early in the 

 season and affect the vines by puncturing the leaves, 

 sucking out the juices and causing them to turn 

 whitish, and sometimes to become shrivelled or 

 withered, is the Leaf Hopper {Typhlocyba vitis). Its 

 attacks are generally more noticeable on the thin- 

 leaved varieties, and of little consequence on the 

 thicker-leaved forms, such as Concords and Worden. 

 The Leaf Hoppers pass the winter in the adult state 

 secreted under leaves and rubbish, and begin their 

 attacks on the vines almost as soon as the leaves are expanded, also depositing 

 eggs which produce numerous young, which develop during the summer 

 months, the number increasing rapidly until the vines may be so thickly in- 

 fested that a swarm of hoppers will rise upon the least disturbance of the leaves. 

 This insect is not easily treated since it is not affected by any sprays upon 

 the leaves, but any destructive agent must reach the Leaf Hoppers themselves 

 in order to be effective. Spraying with kerosene emulsion, taking pains to reach 

 the under sides of the leaves, is perhaps one of the most effective plans, and is 

 particularly useful while the insects are young, but less likely to affect the adults, 

 which take wing quickly when disturbed, and may possibly escape the spray. 

 A plan which has recently been recommended somewhat is known as the 

 Shield method, and consists in covering a canvas or pasteboard stretched on 

 a frame with tar, and carrying this along the rows of vines. The Leaf Hoppers 

 are disturbed by shaking the vines with one hand, while the shield is held in 

 such position that the insects will hop or fly against the tarred surface and be 

 caught. 



The Grape Berry Moth or Grape Seed Caterpillar {Eudemis botratia\ has 

 not until recently been known as a destructive species in Iowa, but I have 

 learned from a Dr. McDonald, of Des Moines, that a caterpillar which evidently 

 belongs to this species, has caused much injury in his vineyard during the past 

 season. It is a species which will prove very troublesome if it becomes abun- 

 dant. The insect is imported, and has long been injurious to grape culture in 

 Southern Europe. The larvae begin to appear in July, when the injured grapes 

 show a discolored spot where the worm 

 has entered. They feed upon the pulp, 

 and sometimes upon the seeds, and if 

 a single grape does not suffice for their 

 growth, two, three or more are attacked, 

 these usually being fastened together with 

 silken threads. 



They are said to pupate upon the vines, 

 folding a leaf as protection. Two broods 



Fig. 697.— Grape-bekry Moth 



a. Moth ; 6, Larva ; d, Injured Fruit. 



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