SCALE INSECTS. 



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insect, itself ; others are covered in loose white material 

 like cotton wool wliich completely envelopes them and 

 gives them their name, mealy bugs. In some the 

 covering- takes the form of thick opaque wax, arranged 

 in more or less regular plates. Another large division 

 ^f has no special covering but the skin of the upper 



rj surface is thickened. In nearly all species the size 



•^ is not more than one-eighth of an inch, the insect 



W being flattened and closely attached to the plant. No 



^^ definite characters can be given by which to distin- 



guish these insects from many others which resemble 

 them. 



Zife Histori/. — The female produces very large 

 numbers of eggs, which may hatch at once or remain 

 dormant for a long period. As a rule these eggs are 

 produced slowly and accumulate under the body of 

 the insect or in a special egg* case attached to her 

 body. The number of eggs is generally some hun- 

 dreds, often thousands. The young that emerges is a 

 small insect, flattened, with three pairs of legs hidden 

 under the body, a long suctorial beak, and minute eyes. 

 The young' walk actively and may go for some distance 

 in search of a fresh food-plant. Eventually each settles 

 down, buries its beak in the tissues of the plant and 

 feeds upon the juices. When grown larger, the skin 

 is shed and the insect often becomes a degraded legless 

 creature hidden under its protective covering. 

 The females moult once 



Fig. 291. 

 The Black Shield 

 Scale. 



more and are then matu.re. 



incapable of 

 after the 

 though the 



in particular 

 throuo-hout 



Most are 

 movement 

 first moult, 

 mealy bugs 

 remain active 

 life. 



The male underg'oes 

 two further moults and 

 after passing through a 

 period of rest, emerges as 

 a tiny two-winged fly, 

 so small as to escape 



Fio. 292. 

 Tlic Black Shield Scale, {Magnified five times.) 



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