76 First Report on Economic Zoology. 



Coccidcc ; the male and female scales differ in appearance and size ; 

 the riiale scales are seldom observed. 



The female scale (Fig 8, a and I) is about one-eighth of an inch 

 long ; in form the scales are rounded behind, but taper to a point at 

 one end — the head end ; they may be straight or curved, and even much 

 contorted. In colour they vary from deep brown to almost grey. The 

 male scale is much smaller than the female and of the form shovm 

 in fig. 9, c. They damage the trees by sucking out the sap by means 

 of long, flexible mouths which they insert into the plant tissues. This 

 scale not only occurs on the trunk and boughs of the trees, but also on 

 the leaf and fruit. Foreign apples are frequently imported covered 

 with this and other scale pests. The scale, as in all Coccidm, is a 

 product formed by the insect which lives beneath it, partly by 

 excretions from its body, partly by the cast skins of the insect, the 

 so-called exuvicc. 



LiFE-HISTOEY. 



The eggs (Fig. 3, a^), are laid by the sedentary female under the 

 scale. They resemble to the naked eye small whitish dust. As many 

 as eighty may be counted under a single scale, but the number varies 

 considerably. The eggs give rise in the early summer to very small 

 active six-leij2ed larvae, which crawl from beneath the scales and 

 may be distributed from tree to tree by the wind, by birds, and by 

 predatory insects, such as lady-bu'ds. They are about one-hundredth 

 of an inch long. In a short time they fix themselves to the plant by 

 their short proboscis and draw away the sap ; the scale then commences 

 to form by the excretion of a few waxy threads and gradually grows 

 to the form shown in Fig. 8. During this period the larva loses its 

 legs and becomes converted into a fleshy legless creature ; the female 

 remains feeding beneath the scale and is provided with a long flexible 

 proboscis, which is inserted into the tissues of the plant. Towards 

 the end of the summer she deposits her eggs and dies, her shrivelled 

 skin remaining beneath the scale. 



If the larva is going to become a male, not only is a different 

 scale produced (most often upon the leaves), but a totally different 

 mature insect. The male undergoes a kind of pupal stage and 

 escapes from the scale as a small winged insect, provided with two 

 rather large wings and a pointed process at the end of the abdomen, 

 which it can insert under the female scale and so cany out 

 fertilisation. The males are very rare, most of the females reproducing 

 asexually. A single brood normally exists in this country. 



