]8 



Remedial Measures. 



Where lilacs are badly covered it will be best to cut out all the 

 scaly wood that can be spared. Lilac will stand severe trimming and 

 does not require a long time to make new growth. If an infested 

 hedge is carefully looked after and the bad shoots are kept trimmed 

 out, this insect can be controlled without the application of any in- 

 secticides. Judicious trimming will also help willow and other in- 

 fested trees and plants. 



Fig. 9. 



The oyster-shell bark louse, MytUastpls pomorum, Bouche : a. female with the egg mass beneath the 



scale ; l>, same from above, showing the normal appearance of the species ; c, a twig 



infested by females ; d, the male scale, natural size and enlarged. 



From the Dlv. Eat,, TT. S. Dept, Agl. 



If cutting out is not feasible, insecticides must be resorted to, and 

 there is only one time when they can be applied with any prospect 

 of success. It has been shown that the insects winter in the egg 

 stage, covered by the female scales, and no application made during 

 that season stands any chance of producing a satisfactory efEeet. 

 Unless the scales can be actually washed off or corroded, nothing that 

 covers them will affect the eggs underneath. It is in June, when the 



