8 



HOW TO IDENTIFY THE SAN JOSE SCALE. 



Appearance of the San Jose Scale. — If we take a San Jose Scale infested 

 piece of bark or an infested apple or pear in the summer or early autumn and exam- 

 ine it carefully we shall find the surface studded with small dot-like bodies. If we 

 crush these, juice or fat will run out from beneath, and if we use a pin or a knife we 

 can easily remove them from the bark or the skin of the fruit. These little dot-like 

 bodies or specks are scales. Now if we examine them more closely with a hand lens 

 we shall see that there are a few circular scales several times larger than any of the 

 others. These are the adult female scales, and they are usually grayish or grayish- 

 brown in color. Further study will reveal a good many elongate or oblong scales 

 about twice as long as broad, and usually grayish or blackish in color. These are 

 the adult males. Examining those that are left we shall find large numbers of little 

 black scales about half the size of the males but quite circular. These are a very 

 important stage of the immature females and males, because it is in this stage that 

 all, or practically all, the San Jose scale winters, and by them we usually identify 

 the insect. In addition to these three forms we shall find, especially on warm days, 

 numerous little orange yellow scales running about. These are the larvae, both 



a. ^ 



Fig. 2. (a) A healthy piece of apple bark showing the natural smooth surface. 



(6) A badly infested piece with the bark completely covered by the scale. This piece 



has an ashy appearance. 

 (c) A similar piece of bark to b, but showing the small circular areas from which dead 

 adult female scales have dropped off. Natural size. (Original.) 



males and females. It is onlv while in this stage that females can move about. 

 Intermediate between these active little yellow larvae and the small black circular 

 stage will be seen little white dots, which are the young larvae that have just settled 

 down and covered themselves over with their first waxy coat. As this covering 

 thickens and hardens it gradually becomes darker, until the black stage mentioned 

 above is produced, so that we shall find many very small scales varying in color 

 between white and black. Of course, what we see with the naked eye, with the 

 exception of the little active yellow larvae, is not the insects themselves, but merely 



