SMALL, ACTIVE INSECTS INJURING THE FOLIAGE 313 



Fig. 480. — Work of the Apple Leaf- 

 hopper. Original. 



means of control consists in spraying thoroughly with tobacco extract 

 as soon as nymphs appear. The spray must be directed to the under 

 side of the leaves and must be applied before the insect has reached the 

 winged stage, in order to be 

 effective. 



The Apple Leaf-hopper 

 {Etnpoasca mali Le B.) 

 A very small whitish insect, 

 winged and active in its ma- 

 ture stage, swarms on the 

 leaves of apple trees and some- 

 times on other foliage, suck- 

 ing the juice of the leaf. The 

 feeding punctures cause tiny 

 white spots, which in time be- 

 come numerous enough to give the foliage a distinctly bleached ap- 

 pearance. On young trees, and especially on nursery stock, the at- 

 tack usually results in a curling of the 

 tender leaves, somewhat resembling 

 the work of plant lice. The insect 

 winters partly as adults in rubbish, 

 partly as eggs in the bark of the 

 trees. There are several generations 

 in the course of the summer. 



In orchard trees spraying with a 

 contact insecticide, such as tobacco 

 extract, \\\\\ kill many of the leaf- 

 hoppers if the material is applied 

 early in the season, before the winged stage appears. On nursery 

 stock a desirable preventive measure is dipping in soap solution. 



The Pear Psylla (P.s/y/^a T^T/ncoZa Foerst.) 

 The pear psylla is a minute, sucking insect, wingless in its immature 

 stages, but active and winged as an adult. It sucks the juices of the 



Fig. 481. — The Apple Leaf-hopper 

 Enlarged and natural size. Orig- 

 inal. 



