.SCALE INSECTS OF IMPORTANCE 315 



find it of advantage, so far as possible, so to locate his orchards as to re- 

 duce to a minimum the danger of this and other insect pests being con- 

 veyed by natural agents from adjacent orchards to his own. A man 

 can never tell what pests a neighbor may unfortunately have in his or- 

 chard, or in a long series of years just how much care that orchard may 

 receive. It is therefore good business to have valuable orchards some- 

 what isolated; and, if one man be fortunate enough to possess several, 

 it would be well to have them somewhat separated and thus offer a seri- 

 ous obstacle to the spread of this or other pests from one orchard to an- 

 other. A row of evergreen trees between adjacent orchards would prob- 

 ably prove of considerable service in preventing the carriage of scale and 

 other insects from one orchard to another. 



Possibility of extermination. There is no one at all famihar 

 with the conditions, who expects to see New York state eventually freed 

 from this pest. It is beyond the possibiHties. The insect may be eradi- 

 cated from certam places where it has not gained much of a foothold, 

 but, as a general rule, it is very doubtful that the pest will be cleared 

 from any locality where it has become even fairly established, because 

 people will not ordinarily adopt the radical measures necessary to exter- 

 minate it. There are records of the insect having been exterminated 

 from Hmited localities, but this line of work is advisable only where the 

 infestation is comparatively recent, the area where the pest occurs sharply 

 defined and distant from other infested trees or shrubs. Exclusion is the 

 most promising method of protecting an orchard and next to that the 

 adoption of methods for keeping the insect within moderate bounds. 

 Because there has been difficulty in controlling this pest, it need not be 

 assumed that such will always be the case. This insect is no longer 

 greatly feared in certain parts of California, and the indications are most 

 favorable for the finding of a practicable method of controlling the insect 

 in the eastern United States. 



Method of extermination. Dig up by the roots every infested tree 

 and others at all likely to have this scale insect on them and burn them 

 at once, unless this work be done in the late fall, when it may be advis- 

 able to allow the uprooted trees to lie in a pile till about June i before 

 burning, in order to permit the escape of any beneficial parasites which 

 may be present. Digging up by the roots is quite important because a 

 few scale insects may be found on portions of the tree below the surface 

 of the ground. A less radical method would be to destroy tiie infested 

 trees as described above and to treat the suspected ones most thoroughly 



