23 



If neglected, the tree is doomed to an early death and might as well be cut 

 down and burnt at once. Where peaches are grown on a large scale, it 

 will pay to fumigate with hydrocyanic acid gas, for which it is necessary 

 to have tents large enough to cover an entire tree. As this is a very 

 dangerous poison, the fumes being destructive of all animal life, it shou'd 

 not be employed by unskilled persons. With proper care and the requi- 

 site knowledge, it may be used to great advantage and will be found :o 

 clear the trees of injurious insects of every kind that may be upon them. 

 The Peach Lecanium Scale (Lecanium persicce). On the twigs and 

 branches may sometimes be found large, soft-shelled, brown scales, very 

 convex and resembling in size and shape the half of a split pea. Like all 

 other scale insects, these live by sucking the sap of the tree and when 

 numbers are present impair its vitality very much. The remedies pre- 

 scribed for the other scales are equally effective for this. Lecanium 



Fig. 37J — Terrapin scale Ev.levanium nigrqfasciatum. Adult females on twig of peach. 

 Enlarged about three times. (After Sanders, U. S. Dept. Agriculture. ) 



scales of many kinds may be found on most fruit and forest trees and 

 upon a great variety of shrubs and plants ; usually they are not very 

 numerous or injurious, but occasionally they occur in immense numbers, 

 crowded thickly together, and inflicting much damage. If the affected 

 tree cannot be treated in the prescribed manner, it had better be cut 

 down and burnt in order that it may not become a centre of danger to 

 others. Several of the species do not confine themselves to any one kind 

 of tree, but will spread to all that may be within reach. 



The Terrapin Scale (Eulecanium nigrofasciatum), Fig. 37^, to which 

 public attention has recently been drawn in the daily press, is a hard 

 hemispherical scale, red in the middle, with black streaks proceeding to 



