Fruit-growing 



263 



the outer bark into the sap-bearing inner bark and sometimes 

 into the soft wood. 



The females give birth to living young, the time of year vary- 

 ing with climatic conditions. In Pennsylvania the first brood 

 appears from about June 1 to 15. The young are very small ; 

 without the aid of a microscope, they look like specks of corn- 

 meal, but when magnified are seen to be oval in shape, to have 

 heads, with eyes, antennae, and a long thread-like proboscis. 

 These insects crawl about on the 

 bark and leaves of the trees for not 

 longer than one or two days or until 

 they find a suitable place in which 

 to insert their proboscides and be- 

 come fixed. This is usually in the 

 bark of twigs, although it is some- 

 times in the leaves or the fruit. 

 As soon as they become fixed, they 

 begin to secrete a waxy covering 

 which comes from the pores of their 

 skin. Thus a scale is formed over 

 the insect, after which it loses its 

 head, eyes, and antennae and does 

 not resemble the crawling insect. 

 The insects do not usually crawl 

 more than five or six feet from the 

 female that gave them birth. Often they fix very near to 

 her, even overlapping her scale covering. 



The young fixed scales are at first white and circular in shape 

 and have the central point. This is their second stage. They 

 inject poison into the plant where they are fixed, suck out sap, 

 and grow. In a few weeks they reach the third or black stage, 

 the winter-resting condition. They continue to grow until 

 they reach their full size, when they are the brownish color of 

 the adult scale. In summer this happens about a month after 

 they are born. They then begin to bear young and this con- 



FIG. 110. San Jos6 scale on 

 twig (enlarged). 



