CHAPTER XII 

 GRAPE PESTS AND THEIR CONTROL 



In common with other cultivated fruits, grapes are at the 

 mercy of numerous insect and fungous pests unless man inter- 

 venes with remedial or preventive treatment. Happily for 

 viticulture, knowledge of the pests of the vine has made such 

 advancement in recent years that practically all are now con- 

 trolled by remedial or preventive measures. Possibly no field 

 of agriculture has had greater need, or received greater aid from 

 science in the study and control of insects and diseases than 

 grape-growing. A separate treatise would be required to treat 

 the pathological troubles of the grape fully ; only such details 

 of the life histories of the several pests to be discussed as are 

 essential to a proper understanding of the control of the para- 

 sites can be given here. 



Insect Pests 



Insects troubling the grapes are numerous, at least '200 hav- 

 ing been described in America, most of which have their habitat 

 on th(> wild ])n)totypes of the cultivated vines of this continent. 

 For this reason, with a few exceptions, the insect pests of the 

 grape in America are widely distrii^uted, abundant, and, there- 

 fore, often very destructive to vineyards unless vigorously 

 combated. The many pestiferous species vary greatly in 

 importance, depending on locality, weather and the variety. 

 Phylloxera, however, the country over, is most common and 

 deserves first attention. 



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