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Diaspinz, or Armoured Scales—e.g., the Rose Scale, Diaspis rose ; and the, 
White Seale of the Orange, Chionaspis citri ; indeed, in the latter it is the male 
that is the more conspicuous of the two, and has suggested the popular 
designation assigned to the insect. 
During its first or larval stage of existence both male and female are alike 
in every Scale Insect. The tiny young issuing from the egg presents the same 
external characters, and is also indistinguishable by size. his casts its skin, 
and then goes through a nymph and pupa stage, a similar molting of the 
tegument marking the passage also from one to the other. The third or pupa 
stage is followed by one in which the insect assumes a winged form (such as is. 
represented on Plate III., Fig. 10). In the Mealy Bug—Dactylopius (Plate 
IL., Hig. 8)—the nymph resembles the larva in having legs and feelers, but the 
mouth organs become obsolete, the peculiar hair-like rostrum being already 
lost with the larval skin. In the second nymph or pupa stage certain pad-like. 
organs are present along each side of the body. ‘These contain the rudiments. 
of the wings that are to appear after the next shedding of the skin. During 
these transformations the Mealy Bug takes little or no food; indeed, it is 
incapable of doing so, and remains in or near the cottony secretion surrounding 
the adult female whose progeny it represents. In the next or adult stage the 
insect is dipterous, or two-winged ; it has comparatively well-developed legs as 
in the preceding ones, relatively large 10-jointed antenne or feelers, two large: 
eyes, but still no mouth-organs. ‘This is the perfect male, which, though 
comparatively large in the case of the Mealy Bug, is still a diminutive insect, 
measuring (in Dactylopius citri) only three-tenths of an inch in length. 
The Soft Scales, or Lecanidew, agree with the Mealy Bugs in that in the 
nymph and pupa or two-nymph stages the legs and feelers are maintained, 
but, unlike that which occurs with these insects, they are throughout their 
duration protected by a hardened shield, resembling that of the female, but 
smaller, relatively longer, and having also a smoother surface. Moreover, 
immediately prior to the issue of the winged insect, this scale becomes pale- 
coloured and ultimately white. The winged form differs trom that of the 
Mealy Bug insomuch as the hind-body does not terminate in a simple rounded 
prominence as in it, but is endowed with a long slender style that is ancillary 
to the sexual union, and arises from the fact that the female insect in 
Lecanium is otherwise inaccessible owing to the expanded border of its shield- 
like covering, and notwithstanding the presence in this of an anal cleft 
therein. But, as already remarked, male forms of Lecanium are but rarely 
encountered. 
The Armoured Scales, or Diaspine, present us with insects of which tbe 
males, like the females, are during their intermediate or nymph and pupal 
stages endowed with well-developed protecting scales—partly formed of 
rejected skins, but principally of specially secreted matter. ‘Their general, 
form, as exhibited in several genera, is shown on Plate I., of which Hig. 2B 
represents the male of the Red Scale (Aspidiotus aurantii); Fig. 14, that of the 
Purple Round Seale (Aspidiotus ficus); Fig. 84, that of the Rose Diaspis (Diaspis 
rosé); Hig. 4c, that of the Peach Diaspis (D. amygdali) ; Big. 7, that of the 
Orange Mytilaspis (JZ. fulva); and Vig. 9a, that of the White Orange Scale 
(Chionaspis citr’). Krom an examination of these figures it will appear that 
the scale of the male is much smaller than is that of the female, also that it is 
narrower. Again, that whereas in some cases it repeats the female scale in 
miniature, in others itis structurally different. This is especially so with the two 
males of Diaspis (Pigs. 84 and 4¢) and with the White Orange Scale (Chionaspis 
citrz) figured. In their case the secreted portion is quite white, and is provided 
in each of them with three low longitudinal keels. It is, as already remarked, 
the white male scale that isso conspicuous in the case of citraceous trees infested 
with Chionaspis citri—the female, greyish brown in colour, being, on the other 
hand, difficult of discernment when occurring upon the bark thereof. The animal 
itself, in both nymph and pupa stages, differs from the young of both the 
Lecanidw and Mealy Bugs (Coccidw) at these periods in their growth, As with 
