•232 JOUKNAL OF THE EOYAL HORTICULTURAL SOCIETY. 
Descri^ption of the Insect. 
To the unaided eye the scale or covering shield of the female 
{'puparium) is more or less circular, and closely resembles the common 
Rose Scale {D. rosce), but is of a dusky white, the old examples being 
:smoky grey or ochreous, and harmonising with the colour of the bark. 
They are of the size of an ordinary pin's head, and measure from 
1 to 2 mm. (Fig. 99, A, B.) Beneath this scale the wingless, legless, 
inert, fixed body of the female undergoes its transformations, lays its 
eggs, and dies. For the purpose of identification it will be necessary 
briefly to describe the salient characters of the female (fig. 99, D), 
which alone affords us the means by which we can separate it from the 
numerous allied species belonging to the same sub-family. It is necessary 
first] of all to boil the insect in caustic potash, stain, and ultimately 
Fig. 100. — Japanese Fkuit Scale 
(Diaspis ainygdali), Pygidium of the female x 250. {Gardeners' Chronicle.) 
mount in Canada balsam, when we shall find the margin of the tail 
(pygidium, fig. 100), which is composed of several segments, to be 
curiously fringed with spines and lobe -shaped organs. In the central 
position above is the anal orifice, and a number of cylindrical tubes con- 
nected with the derm, and it is through these latter that the scale 
covering or shield is secreted. On the ventral surface is the vaginal 
opening, and surrounding it are five groups of circular spinnerets. As 
none but the expert student can discern the minute structural difterences 
between species and species, it is useless here entering further into detail 
concerning them. 
The covering scale of the male (fig. 99, C) is pure white, narrowly 
elongate, and much smaller than that of the female. Within this 
•covering, which somewhat resembles the finger of a glove, the insect 
