36 THE GRAPE-VINE LEAF-HOPPERS. 



but few, if any, of the insects are killed. At the same time 

 another test was made of the effectiveness of the kerosene 

 and water spray against the leaf-hoppers which were at this 

 season largely immature; three strengths were used, viz: 

 1:10, 1:15, 1:20 of water, and beside spraying several rows 

 of vines, leaves which were covered wnth insects, were 

 picked off and sprayed separately. It was found that when 

 1:20 was used it killed ver^^ few, 1:15 killed many of them, 

 while 1:10 killed the great majority, but the difficulty of 

 reaching all the leaves and thoroughly sprajnng the whole 

 vine "v^'as very great as the foliage was at this time fully de- 

 veloped and very dense, and the insect invariably hides on 

 their under side." 



The above report shows that an extract made of tobac- 

 co, and sold under the name "Scabcura Sheep-dip" proved 

 of considerable value, and that if applied early in the season 

 we possess in it the means of protecting our grapes. Experi- 

 ments early next year will show better, however, the true 

 value of this substance. 



Prevention is always better than cure, and much can be 

 done to prevent the undue increase of these insects. They 

 winter in all kinds of rubbish found in and about the vine- 

 yards and adjoining woods and fields. All such rubbish 

 should be collected and burned after the first frosts have driven 

 the insects into their winter quarters. By doing so many are 

 killed by the fire, and still more are exposed to the inclemency 

 of the winter and perish. This burning should be general, as 

 the insects migrate to soiue distance to find suitable quarters 

 for winter; hence the rubbish or dead leaves in neighboring 

 w^oods should also be burned. The neighbors should unite 

 in this work because if one person in the midst of many vine- 

 yards should neglect to do his duty he can harbor enough of 

 these insects to endanger all his neighbors' vines. If mulch- 

 ing is used this material will offer, as long as still fairly fresh, 

 most excellent hiding-places for these leaf-hoppers; and es- 

 pecial care should be taken to prevent them from utilizing 

 such places for hibernation. This can be done in various 

 ways, depending upon the conditions; but everyone recog- 

 nizing this danger will doubtless find means to lessen or over- 

 come the same. 



