26o Bulletin 144. 



Comparing the results of the sprayings made in June and July with 

 those made in November and December, it would seem that the 

 earlier applications are the more effective. In July, as already stated, 

 no live scales could be found, although later developments make it 

 apparent that there were at that time a few isolated scales unharmed. 

 The more recent sprayings, particularly the last one, were as thorough 

 as it was possible to make them, and while only a few scales are 

 alive at the present time the number is more conspicuous than was the 

 case in July, hence the conclusion that the scales are more easily 

 killed in the spring than in the fall or early winter. That this is true 

 seems reasonable when we consider that in the spring the scales 

 are in a growing condition while during the winter they are in a 

 dormant state. 



Methods of applying the insecticides. — Whale- oil soap in a solution of 

 two pounds of soap to a gallon of water is somewhat difficult to apply. 

 In our work with the San Jose scale, thoroughness was conceived 

 from the first to be the basis of all operations connected with the 

 spraying, and it seemed best to apply the soap solution with a brush ; 

 an old paint brush with stiff bristles was used. This makes an opera- 

 tion of this kind a little tedious, but it is surprising how rapidly the 

 work may be done even with a brush ; and a no more thorough way 

 could be imagined. When this solution is hot it is sufficiently thin to 

 permit its being applied with a pump, but on cooling, as it will do 

 very quickly in small quantities, it becomes more or less stringy and 

 semi-soHd in its nature, so that it is difficult to put it on as a spray. 



The kerosene mixture was applied with a Success bucket pump 

 with a kerosene attachment. This pump is made by the Deming Co., 

 Salem, Ohio, and is an acquisition to spraying apparatus. By means 

 of this pump the necessity of making an emulsion with the kerosene 

 is removed. 



General re7narks. — Diluted kerosene, if as effective as our expe- 

 rience indicates, will have several advantages over whale oil soap in 

 fighting the San Jose scale. Not the least important of these is its 

 cheapness when diluted for use, as compared with whale-oil soap, 

 which costs about four cents a pound at wholesale and about six cents 

 in fifty pound lots. The kerosene may be applied to the leaves or 

 buds at any time without injury, while whale-oil soap, in solution 

 sufficiently strong to kill the scales, will injure the foliage and buds, 



