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or bird, and thus be carried to some other tree, where they 

 may crawl off and infest that tree, or they may be blown by 

 gusts of wind on to trees near by. When ready to settle 

 down, they work their beaks into the bark till they reach 

 the sap upon which they feed, then begin to produce waxy, 

 white threads on their backs. These threads soon mat to- 

 gether, forming a circular white scale, and to this are added 

 molted skins as the insect grows. These skins and the action 

 of the weather turn the scale gray or blackish, so that young 

 scales may often show black, white and gray, arranged more 

 or less in concentric rings, though they are so small that this 

 can be seen only under a magnifying glass. In a month or 

 less from the time they were born these young have become 

 mature and in their turn are producing young, and there is 

 accordingly an almost continuous production of young from 

 the middle of June till cold weather begins, the process in 

 Massachusetts usually ending before the first of December. 

 At this time there will be scale insects of all ages on the 

 trees, but all the adults and yoimg scales die during the win- 

 ter, leaving only those which are half or two-thirds grown. 

 The early spring months are used by these in completing 

 their growth, the adult condition being reached and repro- 

 duction beginning, as already stated, about the middle of 

 June. 



Treatment. 



This pest can be successfully treated only during the 

 winter months. Many different methods have been used, 

 but most of these are either worthless or too expensive to be 

 available. 



Trees nearly dead can probably be saved by treatment; 

 but this does not usually pay, it takes the trees so long to 

 recover. In most cases it is better to destroy such trees. 



Where treatment is advisable miscible oils and the lime- 

 sulphur wash are now much in favor for this purpose. 



Lime-sulphur Wash. — This may be made where it is to be 

 applied, or can be purchased ready made. Apparently the 

 home-made material is slightly the better, but this is often 

 offset by the inconvenience or impossibility of preparing it 

 where it is to be used. 



