Scale-Insects, 



2/7 



brood a year. The young are much Hke mites and are active. They have six legs, 

 a pair of antenncC, and a long hair-like rostrum or sucking-tube. Their activity 

 does not last long. They select a place on the shoot or leaf, thrust in the long 

 rostrum, which looks too feeble for such use, and become fixtures. In most cases at 

 the first moult legs and antenn?e are thrown off with the old skin as being of no 

 further use, and a protective shield, formed partly of a waxy exudation and ])artl\' 

 of cast skins, begins to form around and behind them. This is the " scale " that is 

 the distinguishing feature of so many of the species, and which has suggested the name 

 by which they are known to gardeners. There are a few genera in which the grubs 

 retain their limbs and their activity. 



•W •v 



-^^ »*^ 



Some of these are known as mealy 

 bugs, from their excretions taking 

 the form of long flocks or strings 

 of a meal-like powder ; in both 

 cases these emanations consist of 

 wax. 



The scale of the male grub 

 becomes its puparium in which it 

 rests as a chrysalis. In this stage 

 the wings and legs of the perfect 

 Insects are free from the body, 

 though immature and encased each 

 in its separate sheath. When the 

 chrysalis skin is cast off it is pushed 

 out of the scale from the hinder 

 margin, and the winged Insect 

 follows backwards through thc^ same 

 aperture. It is usually yellow or 

 crimson in colour, though a few- 

 species are mauve or brown. The 

 wing is transparent, free from scales, 

 and has not the netted character 

 of the wings in other Insects, there 

 being only a single nervure, which 

 forks, and the two branches run 

 parallel with the fore and hind 

 borders of the wing. A second pair of wings is indicated, as in the diptera, 

 by a pair of balancers, in this case taking the form of " hooked bristles, 

 which fit into minute turned-up haps or pockets in the wings." When not in use 

 the wings lie flat along the body and usually overlap behind. The body ol the male 

 is frequently terminated by two or four very long white lihinients. 



Although the grubs that arc> developing into females are at first indistinguishable 

 from those of the male sex, the difterencc becomes manifest when the latter enter 

 the chrysalis stage, for the females at the corresponding change of skin are unaltered. 

 They grow larger and the scale becomes broader. They have lost all their external 



^ 



PhoU, hy\ 



iir 



- J^ 



\Vc<.t. 



Felted Beech-Scale. 



Ill certain parts of the country this is aconspicuous Insect by association. 

 Biich-trc'cs attacked by it have the appearance of having their trunks 

 lightly coated with driven snow (see pagi' 279). In this photograpli 

 a fi'W of the Insects have been carefully cleaned from the abundant 

 •' wool " tliat completely hides them in nature. That will be at once 

 evident when it is stated that as shown they are niagnilied si.\ty-six 



