7S INSECTS AFFECTING VEGETATION 



with oilcloth which is coated with a sticky substance, made by using 

 melted resin, 1 quart, and castor oil, 1 pint. 



Early in the season the insects will be found mostly on the lower 

 leaves and the frame need not be high. As the higher leaves are 

 invaded the height of the frame must be increased. In controlling 

 the insects in this way it is very important to catch the over-winter- 

 ing adults before egg laying has begun, thus greatly reducing the 

 number of progeny to appear later, and the operation of catching the 

 insects must be repeated at frequent intervals. 



Extensive tests with sprays were also made, and it was found 

 practicable to destroy the young wingless hoppers or nymphs with a 

 whale-oil soap solution, the soap being used at the rate of 1 pound to 

 10 gallons of water. The spraying must be done very thoroughly, 

 covering the under surface of the leaves, as only those nymphs are 

 killed which are actually hit with the spray. This work should be 

 begun when it is observed that the young are becoming common. It 

 is likely that an 8 to 10 per cent kerosene emulsion could be used, 

 which would obviate this difficulty, and would prove equally effective 

 in killing the young hoppers. 



Thorough cleaning up of fallen leaves and trash in vineyards 

 during the winter will undoubtedly destroy many hibernating adults, 

 and if this work be extended to adjacent areas where the insects are 

 likely to find shelter, the reduction in their numbers will be mate- 

 rially greater. Where practicable the burning over of adjacent 

 meadows, wood lots, and spaces along fences is very advisable. It has 

 been observed that in vineyards in which clean culture is practiced, 

 all grass and weeds being kept down throughout the season, the hop- 

 pers are notably less abundant than where this practice is not fol- 

 lowed. The absence of suitable hibernation quarters in the vineyard 

 causes them, largely, to migrate elsewhere, and vineyards receiving 

 such care are much less seriously infested the following spring and 

 summer. 



The grape leaf-hopper secures its food by sucking juices from 

 the interior of the leaf, and arsenical poisons useful against the grape 

 root-worm and the grape berry moth are quite useless against this 

 pest. 



Grape Leaf-Folder. Observing grape growers have often no- 

 ticed, especially during midsummer and later, grape leaves folded to- 

 gether, the interior (upper) surface of the leaf being more or less 

 skeletonized, and within the fold a slender larva, which, upon being 

 disturbed, is apt to wriggle out and fall or hang suspended by a 

 thread. This insect, the grape leaf-folder, is widely distributed and 

 a few are to be found in vineyards almost every year, while here and 

 there throughout their range they may be so abundant as to do seri- 

 ous injury. There are two broods each year in the more northern 

 States and three or possibly more in the South. The insect winters 

 in the pupal stage in the folded and fallen leaves, the moths appear- 

 ing in the spring shortly after the foliage puts put, and the eggs are 

 placed in small patches here and there on the vine. Upon hatching, 

 the young larvae attack the foliage, folding the leaves as stated. Mr 



