PESTS OF THE HOP CROP. 



137 



LEAF HOPPKKS WHICH AKKKCT TIIK HOP 



Several species of the little insects properly called 

 leaf lio])i)crs, hut which vine ,i;r(j\vers have become 

 used to calling "thrips," occur upon the hop ])lant, 

 and in dry seasons sometimes cause the leaves to turn 

 brown and wilt, thus doing about the same character of 



Fia. 70. HOP VINE LEAF HOPPER. 

 Tettigonia confluenta, with enlarged structural details. Enlarged (original) 



damage in dry weather which the hop plant louse does 

 in damp weather. The most serious case which has 

 been brought to our attention was in 1891, when speci- 

 mens of the species here figurctl, namely, Tettigonia 



