No. 4.] 



SCALE INSIXJTS. 



427 



Description and Life History. 



The adult feinalo insect i.s lemon yellow in color, but is 

 covered by a hard, dead scale, which is circular in outline, 

 slightly raised in the centre, forming a sort of nipple, and is 

 about the size of a pin head. Beneath the scale the insect 

 lies, with its beak thrust into the plant till it reaches the sap 

 on which it feeds. The scale being dead, and closely fitting 



Fig. 1. — Sac Jose scale : a, twig showing sc^ale, natural size ; h, portion of bark showing 

 crawling young and scales in various stages. (Howard and Marlatt, Bull. 3, N. S., Div. 

 of Ent., Dept. of Agr.) 



the surface of the plant at its edge, it is impossible to reach 

 and kill the insect beneath l)y any of the milder washes. 



The winter is passed under the scale in this condition, but 

 the very 3'oung and adult insects appear to die during this 

 time. In the spring those which are alive begin sucking the 

 sap, and about the first of June become adult. Reproduc- 



