GRAPE PESTS AND THEIR CONTROL 211 



again come near the surface to feed. The grubs form cells 

 from which the pupae emerge, as we have seen, about the middle 

 of June, timing their appearance very closely to the blossoming 

 of Concord grapes. 



The methods of control are three, namely : destruction of 

 the larvse ; cultivation to kill the pupae ; and spraying to kill 

 the beetles. Since the larvse feed on the roots of grasses in 

 sandy soils, it is easy to locate the feeding ground of the pest 

 and plant it to cultivated crops which destroy the grasses and 

 therefore the larvse. The second method of destruction is 

 similar, consisting of cultivation to kill the pupae. This is 

 accomplished by thorough cultivation during the pupating 

 stage to break the cells and crush the pupse, thus preventing 

 the emergence of the beetles. The third method, however, 

 is the most effective and consists of spraying the vineyard 

 with a sweetened arsenical spray. The spraying should be 

 done as soon as the beetles appear, using arsenate of lead six 

 pounds, molasses one gallon and water one hundred gallons. 

 It is often necessary to make a second application a week later. 

 If rain occurs within thirty-six hours after spraying, the appli- 

 cation should be repeated as soon as the weather clears. 



The grape leaf -hopper. 



From Canada to the Gulf and from the Atlantic to the 

 Pacific, wherever the grape is grown, the small leaf-hopper 

 (Typhlocyba comes) infests the grape in greater or less numbers, 

 feeding on the lower surface of the leaf. Grape-growers com- 

 monly call these insects "thrips," a name, however, which 

 really belongs to a very different class of insects. The injury 

 done by this pest varies greatly with the season and the locality, 

 in some regions it being comparatively harmless and in others 

 exceedingly destructive in seasons when it occurs in abundance. 

 There is great variation also in individual vineyards, those 

 near favorable hibernating places and early spring food plants 



