10 SCALE INSECTS. 



is surrounded by a narrow, reddish band. This, though 

 not characteristic of this sj^ecies only, is one of the first 

 outward marks to be observed around the scale of the fe- 

 males. When a tree becomes badly infested the scales 

 frequently overlap each other and present an outward ap- 

 pearance similar to that produced by dusting the tree with 

 ashes. Under a hand lens, the appearance presented to 

 the writer is much like that given by innumerable minute 

 conical sea-shells sticking to the bark. Upon young twigs 

 the layer of tissue between the outer bark and wood 

 proper becomes a dark red or purplish. The rings thus 

 formed, when scales are not closely situated, is the more 

 striking. This feature should not be overlooked in exam- 

 ination for possible cases of the scale. 



If the tree survives, the parts attacked become knotty 

 and irregular. Young peach trees will usually survive the 

 scale only two or three years. Pears frequently die at once 

 or maintain a feeble existence for a very limited period. 



Leaves are not so liable to attack. When scale is very 

 numerous, however, one or more rows may be found upon 

 upper side of midrib. The infested leaves turn purplish 

 brown. 



Fruit is frequently attacked, and when badly covered by 

 the scale becomes unshapely, rough, and pitted. If it does 

 not fall prematurely, it is always rendered unsalable. Its 

 effects are especially noticeable upon pears. See fig. 1. 



Life-History. 



This term, as applied to in.sect.s, refers to the manner of 

 growth from the egg stage to maturity. The life circle of 

 this scale has received much attention from Mr. Pergande, 

 of the division of entomology at Washington, and it is from 

 his account that this is in the main taken. 



Like all armoured scales, this one spends, save a few 

 hours, its whole existence under the protection of a waxy 

 scale. The short period of active life of the female is 

 passed as a small creeping, immature insect seeking a place 

 to insert its long, slender fibrilhp composing its beak into 

 the tissue of the plant, to remain stationary ever afterwards, 



