CULTURE OF THE GRAPE. 255 



its growth, it frequently changes its skin ; and great num- 

 bers of these cast-off skins are frequently found upon the 

 leaf. In August, the insects become mature, and, with 

 their flying and leaping powers combined, become exceed- 

 ingly active, and exhaustive to the vine. In the autumn, 

 they hide themselves under leaves, and come forth in 

 the spring to lay their eggs, and die. They live by 

 suction of the juices from the under side of the leaf, and 

 even from the fruit. They have been much more destruc- 

 tive to the European varieties of grapes than to our 

 native ; so much so, that some writers have asserted that 

 they were to be found only in grape-houses. This opin- 

 ion is quite erroneous ; for though the thrip, or vine-fret- 

 ter, is almost universal in all graperies, and would prove 

 a serious evil if not held in check, yet it by no means 

 confines itself to graperies. I have seen its evil effects 

 in multitudes of vineyards. Attaching themselves to the 

 under surface of the leaves, they greedily suck the life of 

 the leaf, producing the yellowish, spotted appearance 

 which is seen upon the upper surface. I have seen them 

 increase so much, especially in dry summers, as to exhaust 

 almost every appearance of green upon the vine ; and to 

 fly away at my approach, in such numbers as to make it 

 quite disagreeable to walk through the swarm. In the 



