122 
ease of White Scale of the Peach (Diaspis amygdali, Tryon),* it may secrete 
tortuous threads fromits body-surface and these by interlacing give rise to a more 
or less dense covering. Meanwhile also, in-anticipation of its growth, it has 
commenced to form—also by secretion—a supplementary shield by pouring out 
a waxy substance from certain peculiar glands that occur just within the hind 
border of its body (and elsewhere in the case of some kinds of Diaspinw—e.g, 
Parlatoria), and whose nature and function have both been so ably elucidated 
by A. Berlese.+ This material soon becomes matted together, and, as the 
resulting supplementary shield that thus arises increases; it forms the protecting 
body alluded to. On Plate III. these features, in a scale insect that occurs upon 
the sugar-cane, and is named Chionaspis sacchari-folii, as described by 
Dr. L. Zehntner,f are illustrated: Fig. 4 representing the stationary larva; 
Fig. 5, the skin of this—(a) partly protecting the pupiform nymph, (é) that 
arises in succession to this after its first molt. This has already formed by 
secretion a semi-transparent scale (c), that not only covers but also extends 
beyond it. The nymph, having accomplished this work, again casts its skin, that 
becomes in turn added to the protecting covering, and continues to still 
increase the extent of the scale proper by secretion as before. (This is shown 
in Fig. 6 (Plate II1.), that offers a representation of—(a) the first skin, (0) 
the second skin cast, and (c) the secreted portion of the scale.) This increase 
is made either all aroundit, as in the Circular Scales (Plate I., Figs. 1 and 2) ; 
or in one direction, as in the Mussel Scales (Plate I., Figs. 6,7, and 8). 
Thus the young scale insect undergoes two molts, and has attained a form 
and structure that, in the case of the female, is not to any extent departed 
from until it becomes distended with, or gives rise to, an egg or larva progeny. 
Unlike, however, what has been stated to occur in the Soft Scales, or Lecanide, 
not only is the power of locomotion lost with the first molt but the members 
on which this depends; and, with its legs, it loses also its antennw or feelers. 
It now lies inert, and presents an appearance similar to that shown in Tig. 7, 
Plate ILI., that portrays a magnified image of the insect seen lying naked 
beneath the scale proper when this is raised as above described. Size, shape, 
and general outline, however, vary with the particular Armoured Scale under 
observation, even more so than do these attributes in the protecting scales 
(vide Plate I.). One insect may be kidney-shaped, another top-shaped, another 
circular, another elongate, &c. The same remark also applies to colour— 
white, pale-yellow, orange, red, and purple being exhibited by different 
insects. The features that appear most conspicuous in it are now its mouth- 
organs: a fact in accordance with the experience of what now constitutes its 
predominant habit—that of feeding. 
This peculiar mouth-organ (illustrated on Plate III., Fig. 9) consists of 
a frame-like apparatus with inner (94) and outer (ventral) buckler-like plates 
connected together anteriorly with strap-like bodies. The outer of these plates 
(9a) is named, and answers to, the clypeus in other insects. Beyond the front 
border of the latter in the majority of scale insects are one, and in others—e.g., 
Mealy Bug, Dactylopius—two, much smaller plates (9c). ‘These are jointed to 
it so as to be freely moveable. They form what A. Berlese names the 
“succhiatoio,’’ or sucker-organ, and the mentum of other authors. This 
small plate, or the terminal one when more than one is present, is pierced, 
near its extremity, by a small hole. Through this pass two hair-like bodies 
or set (9e), each of which arises, from beneath the ventral plate or clypeus, 
from two distinct roots (97). These hair-like organs are elastic, may have a 
horny consistency, and correspond to the maxilla (smaller jaws) and mandibles 
Gaws proper) of other insects. They are usually very long, even often 
exceeding in length the body itself, a considerable portion, when the whole is 
not extended, being held in reserve in the form of a loop between the orifice in 
* Insect and Fungus Pests, p. 91. Brisb. 1889. 
+ ‘Le cocciniglie italiane viventi sugliagrumi—Ghiandole sericipare.”—Rivista di Patologia 
Vegetale, vol. iv., pp. 212-246. Firenze, 1896. 
... = “De planten luizen van het Suikerriet op Java,” pp. 10-11.—Mededeelingen van Het 
Proefstation Oost-Java, Nicuwe Serie, No. 36. Soerabaia, 1897. 
