23 



purchase one that can be used against every enemy which maj^ attack 

 his trees. The apparent commercial success of some of these manu- 

 facturers seems to show that the farmer, like most of his fellows, 

 needs to be warned against humbugs. 



SAP POISONS. 



An enticing idea to everyone that owns a tree is that it may be made 

 immune to insects and fungi by putting some compound at its roots, 

 or preferably in a hole bored in the trunk. Copper sulphate, either 

 alone or mixed with other substances, seems to be a favorite remedy with 

 people who accept the idea. Recently a mixture of this sort has been 

 widely advertised. On analysis it was found to contain copper sulphate, 

 bone charcoal, sulphur, and some washing powder. The charcoal and 

 sulphur, which are insoluble in water, made up most of the mixture. 



The theory of such remedies is to jioison the sap of the tree so that 

 insects will either be poisoned by it or else dislike its taste, and fungi 

 will be unable to thrive on account of it. The unfortunate flaw in the 

 theory is that copper sulphate is quite as poisonous to the trees as it is 

 to the pests, and a suflicient quantitj^ of it to have the desired effect 

 would result disastrously to the tree. 



Faith in these supposed remedies would be largely destroj^ed if 

 farmers would test them impartially. For example, in a horticultural 

 meeting not long since a farmer declared that copper sulphate placed 

 at the roots of young trees protected them from aphis attacks. He 

 had treated thus every tree in his orchard the year before, and not one 

 was attacked by that insect, which proved to him that the copper sul- 

 phate repelled the aphides. As a matter of fact, it did not prove this. 

 The thing was just as well and probabl}" more truly explained b}' its 

 not being an ''aphis year." If the farmer had treated all his orchard 

 save a series of check trees here and there throughout the orchard, 

 and the check or untreated trees had been attacked, while the treated 

 trees were free from the insect, he would have had strong evidence in 

 favor of the truth of his idea. Without such check trees b}" which to 

 compare results, any series of experiments is of little value, because 

 the results can not be clearly interpreted. If farmers would bear this 

 fundamental part of every experiment in mind, there would soon be 

 less success too in the quack insect-destro\^er business. 



INSECT PESTS. 



In the following paragraphs the principal insects affecting orchards 

 in the Pacific Northwest are briefly described, their habits are outlined, 

 and the proper remedies are named: 



SAN JOSE SCALE. 



So well known has this destructive insect become that most orchard- 

 ists are familiar with it. Its presence in an orchard is usuall}' first 



