INSECTS OF THE GRAPE 221 



Where systematic spraying with arsenate of lead is prac- 

 tised very Httle damage results from the flea beetle. 



Grape Leaf Hopper. — The leaf hopper is often very injurious 

 in many sections where grapes are grown. These insects 

 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 |th 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 larvte 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 



