82 



STATE BOARD OF HORTICULTURE. 



stroying the symmetry of the tree. It is well to look the trees 

 over, especially if newly set out; whenever one is found having 

 a hole emitting sawdust, poke a sharp wire into the hole and 



tgive it several turns, thereby destroying the borer, 

 -which is invariably inside. If the limb has broken 

 I or cracked from the effects of the borer, it is best to 

 I cut it off. As the trees grow older they somewhat 

 resist the ravages of the borers, which seldom 

 Mature insect, attack large limbs. The beetle is about half an 

 larged. ^^ ^ n j^g^ o f a d ar k; pitch color, having on its 

 wing-covers small or very minute hairs, and is generally cov- 

 ered with a yellowish powder. 



Branch of olive tree infested with black scale (Lecanium olea}, showing 

 larvae of Rhizoblus ventralis feeding on same. 



Natural Enemies of the Black Scale. The black scale has 

 numerous natural enemies, among which is the twice-stabbed 

 ladybird (Chilocorus bivulnerus), which aids in lessening their 

 number to a considerable extent annually; also, many other 



