REPORT OF THE DEPARTMENT OF 

 ENTOMOLOGY. 



THE GRAPE LEAF-HOPPER* 



F. Z. HAKTZELL. 



SUMMARY. 



This bulletin deals with studies on the hibernating habits and 

 spring food-plants of the grape leaf-hopper and with experiments 

 to establish efficient spraying practices. 



Large numbers of adults survived the winter of 1911-12 and 

 threatened many vineyards, but weather conditions during the 

 summer were unfavorable for the nymphs, causing a decrease of 

 the insects during the late summer and autumn of 1912. 



The most favorable hibernating places for the leaf-hopper are 

 fence rows, woods, brush and waste land, weeds or situations 

 where leaves accumulate by the wind. Grass which has lodged 

 also affords winter shelter to the insects. The drier, well-drained 

 soils are more conducive to the safe wintering of the adults 

 than the heavier soils. 



Green cover crops do not afford suitable hibernating places for 

 the grape leaf-hopper during severe winters. 



The foliage of raspberry, strawberry, blackberry, currant, 

 gooseberry, catnip, Virginia creeper, burdock, beech and sugar 

 maple is eaten by the grape leaf-hopper before it migrates to 

 the foliage of the grape. Strawberry and raspberry are the 

 preferred spring food plants. The insects migrate from the 

 strawberry to the raspberry during early May and from the 

 raspberry to the grape during the latter part of May. 



Mating of the hibernated adults takes place on the spring 

 food plants. 



The foliage of the grape is injured by the overwintering adults, 

 but most of the feeding is restricted to the lower leaves, 

 especially those on the young shoots or suckers at the base of 



* Reprint of Bulletin No. 359, February, 1913; for Popular Edition, see 

 p. 727. 



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