SHADE TREE PESTS 57 



now on the market for that purpose. Or a solution of i pound of whale 

 oil soap to 4 gallons of water will be found effective. In the use of any 

 of these compounds, thoroughness is of first importance. They may be 

 sprayed on the insects, applied with brushes or in any other way that is 

 convenient, provided the tree is not subjected to such drenching that the 

 insecticide used will collect around the trunk and cause serious injury. 



EXPLANATION OF PLATES 



Plate i 



Fig. i Elm leaves showing eggs and work of young larvae. 



Fig. 2 Elm leaf beetle (x2). 



Fig. 3 Vertical and lateral view of eggs, very much enlarged. 



Fig. 4 Young larva, very much enlarged. 



Fig. 5 Full grown larva (X5). 



Plate 2 



Fig. 1 Leaf showing holes eaten by elm leaf beetle. 

 Fig. 2 Leaf skeletonized by elm leaf beetle grubs. 

 Fig. 3 Females of elm bark louse, slightly enlarged. 



Plate 3 



Fig. 1 Maple tree borer, Plagionotus speciosus. 



Fig. 2 Elm borer, Saperda tridentata. 



Fig. 3 Work of elm borers, Saperda and Neoclytus. 



Plate 4 



Hand spraying outfit in operation. 



Plate 5 



Power spraying outfit in operation. 



