ATTACKING THE LEAVES. 287 



empty skins remain for some time attached to the leaves. 

 The insects feed together on the under side of the leaves, and 

 are very quick in their movements, hopping briskly aoout by 

 means of their hind legs, which are especially fitted for this 

 purpose. They have a peculiar habit of running s'lOeways, 

 and when they see that they are observed upon one siae of a 

 leaf they will often dodge quickly around to the other. They 

 are furnished with a sharp beak or proboscis, with which 

 they puncture the skin of the leaf, and through which they 

 suck up the sap, the exhaustion of the sap producing on the 

 upper surface yellowish or brownish spots. At first these 

 spots are small and do not attract much attention, but as the 

 insects increase in size the discolored spots become larger 

 until the whole leaf is involved, when, changing to a yellow 

 cast, it appears as if scorched, and often drops from the vine. 

 Occasionally the vines become so far defoliated that the fruit 

 fails to ripen. 



As the leaf-hopper enters the second stage of its existence, 

 corresponding to the pupal state in other insects, diminutive 

 wings appear, which gradually grow until fully matured, the 

 insect meanwhile becoming increasingly active. With the 

 full growth of the wings it acquires such powers of flight 

 that it readily flies from vine to vine, and thus spreads itself 

 in all directions. It continues its mischievous work until 

 late in the season, when it seeks shelter for the winter. 



The Clinton, Delaware, and other thin -leaved varieties 

 suffer more from the attacks of these insects than do the thick, 

 leathery-leaved sorts, such as Concord. These leaf-hoppers 

 are sometimes quite abundant in a vineyard one season and 

 comparatively scarce the next, their preservation depending 

 80 much on favorable weather and suitable shelter for the 

 perfect insects during winter. 



Remedies. — Various measures have been suggested as reme- 

 dies. Since the insect does not consume the outer surface of 

 the leaf, it becomes difficult to deal with it. Syringing with 

 strong tobacco- water or soap-suds, or fumigating with tobacco 



