14 



United States, and the conclusions they warrant would be that, con- 

 sidering the higher cost of the self boiling washes, the small amount 

 of time they save in preparation, and their reduced effectiveness in 

 most cases, offset only by the fact that no kettle to boil in is needed, 

 these self boiling mixtures are not a success and should only be 

 recommended where such a small number of trees is to be treated 

 that the expenditure of fifteen dollars or so for a kettle would be 

 unwise. 



THE K-L MIXTURE. 



This material has been highly recommended by the Delaware 

 Experiment Station and has been tested at a number of places. It 

 was tried here last spring, the formula used being — limoid 33 ys lbs., 

 kerosene 8 ys gals., water 25 gals. The limoid cost one and a quar- 

 ter cents per pound in barrel lots in Delaware, the nearest place at 

 which it could be obtained, and the kerosene at that time cost eleven 

 cents per gallon, making the cost of the materials $1.34 per barrel 

 besides the freight charges. 



It was found quite difficult to produce a satisfactory emulsion of 

 the materials, considerable time being needed, and the results on the 

 scales were far from satisfactory, the trees being badly infested again 

 as early as July twenty-first, while others all around them, treated 

 with the ordinary lime-sulfur wash costing about one-third as much, 

 were in excellent conditon. 



This is the result of only one test, but so far as it goes, it would 

 lead the writer to hesitate to advise the use of the K-L mixture. 



SUMMARY OF EXPERIMENTAL WORK IN THE UNITED 



STATES. 



The San Jose Scale has probably been the subject of a larger 

 number of tests of treatment in this country than any other insect, 

 over five hundred separate experiments having been published. To 

 summarize these is a difficult and perplexing task, but has been 

 undertaken in the hope that at least a few general facts might be 

 brought to light, and the following statements represent what has 

 been found. 



