15 I 



The cuttings should be burnt or taken to some distance from any 

 plants likely to become infested by crawling young, should any hatch. 

 If this cutting is for any reason undesirable, the question of apply- 

 ing insecticides arises. 



In ordinary seasons the insects are not sufficiently abundant to be 

 a real menace to a tree and may be left without treatment. There 

 is sometimes a period during which they become increasingly abund- 

 ant; but with this increase comes also a corresponding development 

 of the natural enemies. So, as a rule, a season, during which the in- 

 sect is unusually plentiful, is followed by one in which it is practically 

 harmless. 



Where it is desired to keep trees or shrubs entirely clean, a diluted 

 petroleum, either crude or distilled, to which some soap has been 

 added, will be most useful. This matter of insecticides is more fully 

 referred to later, and in this connection it is only necessary to say 

 that, whatever is used, it should be applied as soon as possible after 

 tho fluffy masses become fully apparent on tlie trees. The oily or 

 soapy materials penetrate into the masses, clog or mat the cottony 

 fibres and make it impossible for the developing young to get through. 



If, for any reason, it is impossible to make an application at that 

 time, it will be better to wait until the young are noticed. That can 

 be easily determined by cutting an infested twig and placing it in a 

 box with white paper. As soon as the paper begins to be covered with 

 brown moving atoms, the time is at hand for an effective application, 

 and then a thorough spraying of the infested trees with fish oil soap, 

 one pound in five gallons of water, i\'ill result in the destruction of 

 the young. At that period the insects are entirely unprotected, and 

 even under normal conditions not more than 3 or 3 per cent, of 

 the larvffi ever succeed in fixing themselves to the surface of the plant 

 tissue. A thorough drenching with a proper insecticide will reduce 

 this percentage to so small a one that the trees may be considered 

 clean for the season following. 



As the tendency of this scale is always toward the outside, it will 

 not be necessary to get into the interior of the tree, nor to spray 

 beyond the region actually infested by the white scales. It is quite 

 usual for trees to have the upper branches clean, even though the 

 lower ones are badly infested. In such cases the lower branches only 

 need be treated, care being taken to reach the full extent of the in- 

 festation and a little beyond it. 



