16 MISSOURI AGRICULTURAL EXPERIMENT STATION BULLETIN 176 



with a nicotine solution promptly. It may be combined with the regular cluster 

 or calyx sprays. Commercial nicotine sulphate containing 40% nicotine used 

 at the rate of one pint to one hundred gallons of water or combined with one 

 hundred gallons of regular spray mixture is very effective. On young orchard 

 trees the same solution may be used. In the nursery where the buds, leaves 

 and growing tips are being injured spray promptly with the nicotine solution 

 or where practical dip the infested tips in the solution. 



Leaf-hoppers. Apple trees in the nursery and orchard are attacked by 

 two common leaf-hoppers. In the orchard the rose leaf-hopper and the apple 

 leaf-hopper are often both very 'troublesome while on nursery stock the latter 

 is especially injurious. 



Since 1910 the apple leaf-hopper (Empoasca mali) has repeatedly attracted 

 attention in the nurseries of the state. In 1911 and 1912 it was especially in- 

 jurious. Like the plant lice it feeds by extracting sap from the young leaves 

 both as the immature nymph and as the adult. This causes a curling of the 

 leaves attacked somewhat like plant louse injury. The characteristic white 

 speckled appearance on the upper surface of injured leaves on bearing trees is 

 less pronounced on the young vigorous nursery trees tho in severe cases it may 

 show up some. This species passes the winter in the adult winged stage in 

 dry grass and other protection about the orchard or nursery. In the spring 



FiG. 18. Apple Leaf -hopper; trap used for running over rows of nursery trees to catch 



adult leaf-hoppers 



