No. G. UEi'AliTMENT OF AORICULTURE. 245 



come unsaleable. He can expect uo present help from nature; but 

 I (U) not mean to sa}- that changes in natural conditions will not in 

 time make maiters more oas}'. California sull'ered for a quarter of a 

 century and still must fight in some localities. We have had the in- 

 sect scarcely more than a decade; yet in New Jersey, horticulturists 

 are hokling their own against it. 



If the fruit grower decides to fight, he must, if he expects success, 

 realize that it will not Le a short, sliar]) effort, but a long, steady task 

 that is before him. He must become fully ac(iuainted with all stages 

 of the insect and its habits; not from reading this bulletin alone, but 

 from personal verification of its statements, in the orchard. He 

 must become ac(iuainted with the peculiarities of his trees; what 

 treatment they will stand, and what he must avoid. He must de- 

 termine by actual experiments, based upon the information here 

 given, just what he can do most effectively and most economically. 

 No one application of any material can be completely successful, be- 

 cause it is a physical impossibility to hit every scale on a tree of any 

 considerable size. There are always a few protected examples that 

 escape our most thorough treatments and these will serve to restock 

 the trees. A little carelessness may allow so many to escape that 

 in a single season a tree may become as bad or worse than it was when 

 the treatment was originally made. Finally, he must determine 

 whether he will depend nminly upon summer or winter work, or 

 whether he will combine the two. 



In summer the presence of the foliage makes the use of the more 

 powerful insecticides impossible; but on the other hand the insects 

 are much more easily killed. In winter very caustic or very pene- 

 tratiug applications may be made; but the insects are dormant ane 

 better protected than at any other period of their existence. 



SUMMER TKEATMENTS AND THEIR RANGE. 



Summer treatments may begin with the date when the scale first 

 begins to reproduce — June 10 — and need not end until reproduc- 

 tion ceases — about November 15. Before the former date the scales 

 are not more easily penetrated than during the winter; after the latter 

 date those that may be killed l)y summer mixtures would die even 

 if no application was made. 



Summer mixtures are such as may be applied to living foliage or 

 actively growing shoots without causing injury. To be worth con- 

 sidering here, they must also kill the scale at the strength at which 

 it is safe to use them on foliage. 



