INSECTS AND PLANTS 71 



covered with a greyish, rather rough, scurfy deposit, or an 

 equally good description is to say that the tree appears to 

 be coated with ashes, stem, branches, and fruit alike attacked. 

 The leaves also are not immune, but on them the tendency 

 is for the scale insects to arrange themselves in two or 

 more quite regular rows on either side of the midrib. A 

 characteristic feature, though one which occurs sometimes 

 in other scales, is a peculiar reddening effect which it pro- 

 duces on the skin of fruit and tender shoots ; in fact, the 

 quite young scales would be most inconspicuous, when 

 present in small numbers, were it not for the striking 

 reddish-purple circling ring around each one. The scale 

 insects pass the winter in a half-grown state, so small as 

 to be only just visible to the naked eye, the male scales 

 preponderating to the extent of ninety-five per cent. 



Early in April, in America, the winter males (fig. 14) 

 pupate and emerge ; being winged, they are able to travel 

 from tree to tree, and mate with the winter females, after 

 which they disappear, for their work is done. About a 

 month later these females begin to produce living young, 

 and in this respect they differ from most other scale insects 

 which deposit eggs. The production of the new genera- 

 tion extends over a period of six weeks, when the winter 

 females die. The newly arrived, orange-yellow, six-legged 

 larva is at first soft, and remains stationary, with its legs and 

 antennae folded against its body ; soon, however, it hardens, 

 escapes from its mother's protecting scale, and runs about 

 the plant, on which it finds itself, in search of a suitable 

 place to settle (fig. 15, A). When the resting place is 

 selected, the larva works its sucking beak through the 

 bark, and folds its legs and antennae beneath its long ovoid 

 body, which then becomes nearly circular in outline (fig. 

 15, B). Very minute fibrous, waxy filaments are then 

 secreted all over the body (fig. 15, c), and, as they become 

 more and more dense, the insect, within two days, becomes 

 entirely concealed by a pale grey shell or scale, with a 



