N). fi. DEPARTMENT OF AGRICULTURE. 571 



operator thinking- that if a little is good, more is better aud coiise- 

 quently applying his insecticides so strong as to cause injury or 

 even death to the plant. 



The winter remedies for this pest are various and while oil is 

 recommended by some persons, and I would use it upon my own 

 trees, it is not to be recommended by me for you to use upon your 

 trees. The reasons for this are that you are likely to put it on 

 in a way that will kill the tree and this can be prevented only by 

 extreme care and observation of various essential conditions. If 

 I were to use oil I should choose either common refined kerosene 

 or lamp oil or lijjlit crude petroleum. I should prefer the latter of the 

 heavy grades with a specific gravity of 43 degrees Baurae, or heavier. 

 The reason for this is that the heavy oils contain the paraffine and 

 other heavy substances that do not penetrate readily but stick 

 to the bark and this makes it permanent and lasting, as do the 

 latter oils. I should also choose a sunshiny and windy day in order 

 to make the evaporation as rapid as possible. Then I should select 

 the Vermorel nozzles, each with an orifice of not more than one- 

 thirtieth of an inch and I would see that the pressure upon the 

 liquid for the spray was as great as my apparatus could bear in 

 order to make the finest possible spray. I would thus endeavor 

 to secure a fine spray and rapid evaporation and by a single sweep 

 up and down each side of each infested branch I would finish the 

 operation, aiming to give only a mist of oil and not enough to make 

 the branches even wet. By no manner of means should enough 

 be applied to run together in drops upon the twigs or limbs. ^Yhile 

 I could do this and kill the pest, and save my trees, I fear that my 

 hearers would not be sufficiently careful and consequently, in order 

 to save your trees, I would recommend the lime-sulphur washes 

 which have been used with complete success and satisfaction. Be- 

 fore mentioning this in detail, however, I wish to speak of whale 

 oil soap, Vviiich is a first class insecticide. Two pounds in one gallon 

 of warm water will kill insects but it is likely to prove injurious 

 to the fruit buds if applied at any other time than very shortly 

 before they open in the spring. For any trees and shrubs that are 

 not going to produce fruits this is a desirable substance to use as 

 a wash or spray for the San Jos(? Scale. I should also call atten- 

 tion to the fact that our trees vary in hardiness. The apple and 

 pear are the most hardy; then, in order, come the plum, cherry, 

 peach and finally the apricot. Most substances that can be used 

 with safety upon the apple and pear will injure and may even kill 

 the peach and sometimes the plum. However, it may be said in 

 favor of the lime-sulphur washes that these can be applied in any 

 amount ilpon any and all kinds of trees and shrubs with safety 

 and one does not need the experience and precautions that are 



