Il8 ON THE SCALE INSECT OF MULBERRY TREES. 
margins of the same is beset with four pointed strong processes 
arranged at regular intervals. When a nearly circular depressed 
cocoon (scale) attains about i mm. in diameter, the pupa be¬ 
neath it undergoes the last or third moult. The moulted skin 
which is of a dull brownish red color, becomes also part of the 
scale, thus the brownish red mark on a fully formed scale is 
nothing else than the moulted-skin of a pupa (Fig. 9. b. PL. I.). 
At the moment of moulting, the pupa-skin is split up lon¬ 
gitudinally on its ventral surface, and a female insect may 
come forth. Remaining in the same position, that is, exactly 
beneath the moult-skin, it attaches itself firmly to the bark by 
penetrating it with its long filamentous rostral setæ. The newly 
hatched female scale insects secrete also fine threads from the 
pores, which open on the posterior region of their bodies, and 
these secretions accumulate at the periphery of the already 
formed scale, thus increasing its dimensions. In this way the 
scales attain their normal size. 
The scales (Fig, 21. PL. II.) are formed either in groups or 
are scattered sparsely over the bark of twigs or branches, and 
most of them, lying beneath the epidermis of the bark, present 
a dull greyish yellow aspect, which makes it very difficult for 
us to observe (especially when they lie very sparsely), owing 
to their color being similar to that of the bark. 
As I have mentioned before, our scale insect breeds only 
twice a year; instead of three times, like the species Diaspis 
pentagonia Targ. observed by Mr. Y. Contagne. 1 
IV ) Determination of the Species of the Scale Insect. 
The want of sufficient literature on the scale insect makes 
it very difficult to determine its exact species. But still we 
may say the scale insect of the mulberry trees unquestionably 
belongs to the genus Diaspis whose characteristics Mr. Albert 
C. F. Morgan 2 has described in his work “ Observations on 
Coccidae.” Its specific characters agree to a certain extent 
with those of the Diaspis pentagonia, Targ., which Messrs 
Targioni-Tozetti and Franceschini, 3 and also Mr. G. Coutagne 1 
have very accurately described ; but still some differences may 
exist between Diaspis pentagonia, Targ, and our Japanese scale 
