April, 1886.] 245 



perfect. The scale is formed by the moulting of the successive skins 

 lof the insect, combined with and augmented to a greater extent by 

 the secretion by the insect of a waxy matter, which soon hardens into 

 Ispecial forms ; in some genera the scale is wholly formed of such 

 secretion. The insect in all cases lives beneath the shield, the apterous 

 female laying her eggs there and her body then drying up ; the male, 

 losing its mouth organization when it becomes a pupa, when it has 

 attained its wings emerges backwards. The scales of the male, as a 

 rule, are different in form and size to those of the female, as will ap- 

 pear in the following notes. Directions for rearing the males from 

 the scales will be found p. 14, ante. 



From the adult female scales many Hymenopterous parasites of 

 different genera will be sure to appear, and may be obtained by securing 

 the scales in the same way as those of the males. I have several 

 reared from Lecanium which are very much at the service of any 

 specialist. 



Scales. 

 DIASPINA. 



Scale formed in part of moulted skins and in part of secretion by the insect. 

 Aspidiotus — circular or nearly so ; exuviae central or lateral in ^ , concealed, covered 



with a pellicle with a raised point in the middle. 

 Diaspis — ? circular ; <? long, carinated, larval skin at one end. 

 Chionaspis — $ elongate, narrow in front where the larval skin is, greatly widened 



posteriorly ; <J small, narrow, linear, elongate, mostly carinated. 

 Mytilaspis — long, narrow, mussel-form, alike in both sexes, larval skin anterior, $ 



smaller than $ , with only one moult, $ with two moults. 

 Fiorinia — ? , larval skin anterior, the rest of the scale wide with almost parallel 



sides, and formed of secretion anteriorly ridged lengthwise ; <? smaller, of 



similar form. 

 Asterodiaspis — $ , circular, lenticular, somewhat drawn up in the centre, the mar- 

 gin showing a filmy fringe, which is secreted by spinnerets on the margin of 



the insect ; S long-oval. 



LECANINA. 



Scales formed wholly of secretion, with a deep cleft in the posterior margin ; form, 

 $ , gibbous, hemispherical, inverted boat-shaped, or sacs covered with cottony secre- 

 tion ; (? , oval, plano-convex, thin and waxen. 



Lecanium — $ , form various, more or less convex, hemispheric, or inverted boat- 

 shaped ; (J , oval, slightly convex, waxen, delicate ; imago in April. 



JPulvinaria — $ , form like the preceding, but flatter, with a mass of cottony material 

 containing the eggs protruding from beneath (ovisac) ; J imago in April. 



Signoretia — a complete sac of very thin felted pellicle ; very small. 



Eriopeltis — ? , an oval sac covered with woolly matter ; (? in a waxen scale ; imago 

 in July. 



Lichtensia—8SiC of cottony material, but with a skin beneath. 



