SCALE-INSECTS. 



stationary, although in some cases, before reaching their full 

 development, they move about, carrying their houses with them. 

 The naked insects may be either stationary or active. 



They attach themselves either to the bark or stem of a plant 

 or to the leaves. In the latter case it is rare to find them on 

 the upper side ; but, on turning over a leaf, the under-surface 

 is frequently found covered thickly -with them. 



In many cases they exude, in the form of minute 

 globules, a whitish, thick, gummy secretion, answering probably 

 to the "honeydew" of the Aphididse. This secretion drops 

 from them on to the plant, and from it grows a black fungus, 

 which soon gives an unsightly appearance to the plant. This 

 fungus or " smut " is an almost invariable indication that a 

 plant is attacked by insects,* and may, indeed, give a useful 

 warning to tree-growers. It is not, however, produced in 

 appreciable quantities by all species. 



The manner of feeding upon the plant is the same as in all 

 the families of Homoptera namely, by means of a protruding 

 rostrum, beak, or trunk, situated on the under-side of the 

 insect. As there is not, in the female Coccididse, any well- 

 defined division between the head and the rest of the body, this 

 rostrum is seen, on turning over the insect, in the form, usually, 

 of a minute conical projection between, or nearly between, the 

 first pair of legs, if the legs are present, or a little within the 

 circumference, if the legs are absent (Plate i., Fig. 5). An 

 ordinary lens will generally show, springing from the point of 

 the conical rostrum, three or four longish, very fine, curling 

 bristles. These bristles are, in fact, hollow tubes, and the insect, 

 inserting them into the leaf or bark of the plant, sucks through 

 them its food. It is thus plain that, with often great numbers 

 of scale-insects sucking at it pumping, as it were, its life-blood 

 through their rostra a plant must of necessity suffer greatly. 



Birds do not, as a rule, seem to care much about eating 

 the Coccididae, whose work is thus little interfered with by 

 them. The " white-eye " (Zosterops) or " blight-bird " has 

 been seen feeding on scale-insects ; but its visits are few and far 

 between, and its assistance to the gardener in this respect not 

 great. The Coccididse are, however, much subject to attacks 



* Not necessarily a Coccid insect : the fungus may also grow on the honey- 

 dew of Aphis ; but it is easy to recognize the difference between these insects- 

 In every case there is come insect at work where the fungus is. 



