234 THE GRAPE 



feed upon the under side of the leaves, and they often become 

 very abundant. Their injury causes small white spots to 

 appear on the leaves. These spots are made by the insect 

 sucking out the chlorophyll from the plant. As the amount 

 of injury increases, the leaves turn yellow and the fruit is 

 reduced in size and in quality. The adult insect is about 

 | inch in length. The wings are marked with red and 

 yellow. The nymphes are a light yellowish green in color. 

 They feed in the same way as the adults. The insects come 

 in the early spring and feed on whatever foliage is available 

 until the grape leaves appear. 



Various devices and methods of control are in vogue. 

 Owing to the jumping habit of the insect several patent 

 arrangements have been introduced. The use of sticky fly 

 paper is also effective. A device made by stretching cloth 

 on wooden frames against which the hoppers strike is some- 

 times used. The cloth is painted with a sticky material 

 made by mixing 1 quart of melted resin with 1 pint of castor 

 oil, and as the insects strike the cloth covered with this 

 material they stick fast and are killed. Spraying the vines 

 with 1 pound of whale oil soap to 10 gallons of water is also 

 used. A 10 per cent, kerosene emulsion is effective and often 

 employed. Several applications of an insecticide are usually 

 necessary. If the vineyard is thoroughly cleaned up every 

 year many of the hibernating insects are killed and therefore 

 less damage results. 



Grape Berry Moth. — The grape berry moth is a small moth 

 with a wing expanse of about § inch. Wormy grapes are 

 largely due to the larvae of this moth. The injury done 

 by the first and the second brood is somewhat different. 

 The first generation larvee web the cluster of grapes together 

 either before the blossoms open or soon after the grapes set. 

 The later brood, however, bores into the green fruit, causing 

 purplish spots to mark the entrance of the insect. It is 

 obvious that if the first brood is large greater damage will 

 be done, since each worm practically destroys a bunch of 

 grapes, while the later brood destroys only the berry. 



Spraying with arsenate of lead at the rate of 2 pounds to 

 50 gallons of water is effective in destroying this insect. 



