Insect and Disease Control 237 



up of the "scale" that is secreted by each insect very early 

 in its life as a protective covering. Individually each fe- 

 male insect when fully mature appears to be a minute cir- 

 cular grayish speck or "pimple" not as large as a pinhead 

 with a nipple-like prominence in the center. What is ac- 

 tually seen is, of course, the "scale" under which the yellow- 

 ish colored insect itself resides. The male insect, that is 

 the scale, is considerably elongated in form. 



Distribution of San Jose scale. 



The San Jose scale has become so widely disseminated 

 that it may be said almost literally to be unrestricted. It 

 is likely to occur wherever peach trees are grown. 



Life history and habits. 



This insect passes the winter on the bark of the host 

 plant, a large proportion of them in a more or less immature 

 condition. In this stage the scales are dark gray to blackish 

 in color. With the renewal of the growth of the tree in the 

 spring, the insects resume their development, and within 

 a month or so the females begin to bring forth living young. 

 These are exceedingly small, yellowish insects hardly dis- 

 cernible with the naked eye. They crawl about for a few 

 hours only, when they become permanently fixed on the 

 bark, foliage, or fruit, as the case may be. The protective 

 scale is then secreted, or it may begin to form even 

 before the insect locates permanently. When it finally 

 settles down, the insect penetrates the bark with its long 

 thread-like beak and begins to suck the sap by which it 

 is nourished, ^^^len an insect once becomes fixed in a 

 particular spot, it has no power to move further from 

 place to place. 



