SCALE-INSECTS, BARK-LICE, MEALY-BUGS. 235 
Diaspis rose Bouche. (The Rose Scale). 
This is a round or circular, pure white or very slightly yel- 
lowish-white scale, sometimes very common on neglected rose, 
raspberry and blackberry bushes, where it attracts the attention 
by forming such a striking contrast to the greenish or reddish 
shoots, hence is readily observed. It is most abundantly found 
on the stems of roses that grow close to a wall, trellis or other 
support, where the insects are better sheltered. As can be seen 
Fig. 186.—Diaspis ros2 Bouche; 1, scales, actual size; 1a, female scale; 1b, male 
seale. After Comstock, Div. of Entomology, Dep. of Agriculture, 
in the illustration, Fig. 186, the male scale is very small and nar- 
row. Fig. 186, Plate XV, shows an infested twig. The life- 
history of the insect is very similar to that of the Scurfy-scale 
described later. 
Diaspis cacti Comst. (The Cactus Scale). 
One of the most conspicuous and beautiful of the green- 
house scales is the zound or white scale of the cactus. The scales 
possess two different forms, of which the female scale is about 
