16 



DKSCKIl'TKiN OK THE SCALE AND INSECT * 



The female scale is shown 

 in Fig. 5, a, of the natural 

 size, on a moderately infest- 

 ed pear, and at b. greatly 

 enlarged. It is quite flat, 

 nearly circular in outline, 

 about one sixteenth of an 

 inch in diameter, and dark, 

 mottled with gray, in color, 

 with a small elevated spot 

 at or near the centre, which 

 is black or yellowish. 



The male scale is "black, 

 somewhat elongated when 

 fully formed. The larval 

 skin is covered with secre- 

 tions ; its position is marked 

 Y / by a single nipple-like prom- 



inence, which is between the 

 centre and the anterior mar- 

 gin of the scale. The 

 scale of the male is more 

 abundant than that of the 

 female. It is often oval in 

 shape and smaller in size 

 than the female." 

 When these scales occur in large numbers on the twigs (Fig. 6) or 

 leaves they frequently overlap, and are not easily distinguished with- 

 out a magnifying glass. The general appearance which they give 

 is of a greenish, very slightly roughened scurvy deposit. The 

 natural color of the limbs of ihe peach and apple is quite obscured 

 when these trees are thickly infested, and they then have the appear- 

 ance of being coated with lime or ashes. When the scales are crushed 

 a yellowish liquid appears, resulting from the crushing of the soft, 

 yellow insect beneath, which indicates the existence of living scales 

 on the trees. 



Fig. 5.— ft, San .los& scales on apeai-; 6, a f e- 

 ■male scale enlarg'ed. — From Department of Agri- 

 culture. 



*Tlie cuts used to illustrate this paper are from the United States Department 

 ■of .\gricnlturc, through the kindness of Prof. L. O. Howard. 



