April. '09] JOURNAL OF ECONOMIC ENTOMOLOGY 173 



we believe that the clipping of the roots of trees in any of the mixtures 

 at any time to be a rather questionable procedure. They also show 

 that only strictly dormant nursery stock should he dipped in any 

 of the solutions used. 



While no scale developed on any of the infested trees after the treat- 

 ment in either experiment, in view of the published results of other 

 experimenters and the limited numlier of infested trees included in 

 these tests, we consider that these results may lie inconclusive. 



Finally these varyinp- results go to show that fui'ther experimenta- 

 tion is necessary in order to establish what may be expected from such 

 treatment, even if its adoption for general use should become desirable. 



President Forbes: Any discussion on this paper? 



A IMember : I would like to ask whether you would recommend dip- 

 ping to the grower who wants to take every precaution to have his 

 trees free from scale? I had that question from a correspondent the 

 other day and would like information concerning it. We get scale 

 right along on our trees when the certificate says they have been fumi- 

 gated. With the average man fumigation is a little difficult. Is 

 fumigation safe enough and satisfactory enough to warrant our ad- 

 vising growers to dip the nursery stock, omitting dipping the roots ? 



Mr. Parrott: We have made some experiments in dipping trees. 

 If the farmer desires to dip, I would suggest that he use one of the 

 miscible oils. I do not believe that the lime-sulfur wash has the pene- 

 trating qualities of the miscible oils, for in our comparative tests of 

 these sprays we have had much better results with the latter. More- 

 over, I do not believe that the average farmer will fumigate, and if he 

 desires to treat his trees before planting, I would suggest a miscible 

 oil, but I think it would be better for him to plant his trees first and 

 then to spray them with either the lime-sulfur wash or a miscible oil. 



Mr. Skinner: INIr. President, I don't know that it has ever been 

 tried in dipping, but I would like to have some one try solutions of 

 potassium cyanide of varying strength. It ought to be very effective 

 and very cleanly and inexpensive. 



jMr. J. B. Smith : I would like to answer Doctor Skinner that it is 

 extremely eft'ective. It kills every plant dipped in it. 



Mr. Skinner: I would like to ask Doctor Smith the strength? 



Mr. J. B. Smith: I run it down to where it wouldn't hurt insects 

 and it still killed every plant I tried it on. 



Mr. Parrott : Since this question has come up, I would like to ask 

 if anv of the members have tried anv of the concentrated tobacco pre- 



