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through the winter until they hatch in the late spring or early sum- 

 mer. Then the very small, yellowish insects move out from under- 

 neath the parent scale and settle in suitable spots, where they he- 

 come fixed, and insert their beaks into the wood for the absorption 



of food. 



Scale insects are best controlled by a dormant spray. Com- 

 mercial lime sulphur is commonly used ; Dendrol, Sunoco, and other 

 miscible oils are also effective when applied, according to the direc- 

 tions of the manufacturer, in the late winter or very early spring. 

 In the summer very badly infested branches may be cut out and 

 burned. 



Lilac Borer. — Lilacs are often infested with insect borers. Per- 

 haps the commonest one is the lilac borer, which also occurs on the 

 ash. The borer is the larval stage of a moth, which appears late in 

 May or early in June. In a short time the eggs are laid in cracks 

 in the bark, and soon hatch out into minute larvae. These bore 

 their way into the tender stems, gradually increasing in size, feeding 

 on the woody tissues of the plant. When winter approaches, the 

 larvae pass into more or less of a resting stage, but renew their ac- 

 tivities again in the early spring. About the first of May the larvae 

 reach the adult size and pupate, hatching out in a few days into the 

 adult moths. 



The most effective control is the pruning out of the infested 

 branches. This is best done either in the late summer or early 

 spring. 



Powdery Mildew of the Lilac. — The only common fungus dis- 

 ease of the lilac is caused by a powdery mildew. In the late sum- 

 mer and fall the leaves are likely to be more or less covered by a 

 whitish growth, the vegetative stage of the fungus. Later in the 

 season the small, dark, spherical fruiting bodies of the fungus ap- 

 pear. 



The mildew is quite superficial in its growth on the leaves and 

 ordinarily it docs relatively little damage, aside from the discolora- 

 tion. Year after year, however, it may be expected to appear, 

 particularly on the leaves of the younger, more vigorous growing 



branches. 



Except for the discoloration, it is hardly worth-while bothering 

 with attempts at control. However, the application of very fine 



