142 JOURNAL OF ECONOMIC ENTOMOLOGY . [Vol. 12 



Mr. p. J. Parrott: But you are making that recommendation? 



Mr. Alvah Peterson: Yes, because it is the best recommendation 

 we have, so far as we know at the present time. 



Mr. W. J. ScHOENE : The hatching of these eggs and the appearance 

 of the aphids have been noted for several past seasons, not only by the 

 entomologists but also members of the other departments. The 

 fact has been noticed that the eggs hatch many weeks in advance of 

 the time when the buds show green at the tips. We found them late 

 in February and early in March, when the aphid had no chance to 

 obtain food. 



Mr. Alvah Peterson: What species? 



Mr. W. J. ScHOENE : Avence. 



Mr. R. C. Osburn: I would like to ask Dr. Peterson whether his 

 observations indicate that avence is of any importance in getting out 

 the test? What experiments have you to show that the nicotine 

 should be used one to four hundred, as against one to nine hundred? 

 The bulk of the United States probably uses nicotine sulphate at the 

 rate of three quarters of a pint to one hundred gallons, and it would be 

 very interesting to know why New Jersey reduces the recommendations 

 to one to four hundred? 



Mr. Alvah Peterson: In the first place I might say that our 

 recommendation is one to five hundred. 



In respect to the difference in the amount of injury done by the vari- 

 ous species, of course that which is done by the avence is least of all. 

 I fully expect to see injury done by avence this coming spring for they 

 undoubtedly will be abundant, because I know of one orchard today in 

 New Jersey where the eggs are actually so abundant that you cannot 

 touch a square inch of the large trunk of the tree without crushing a 

 number of eggs. When these eggs hatch and come out and attack the 

 young, green buds, it stands to reason that there will be some injury, 

 even though it may not be as marked as that of sorhi or pomi. 



In respect to one to five hundred or one to a thousand, or whatever 

 might be recommended in using nicotine sulphate, I might say that 

 we do not get as good a clean-up with one to a thousand as we do with 

 one to five hundred. Mr. Barclay carried on experiments in his or- 

 chards with one to five hundred and one to a thousand, which showed 

 conclusively that one to five hundred is much better. Dr. Headlee has 

 carried out some experiments along that same line. Probably he 

 could give you some pointers on this. 



Mr. T. J. Headlee: We have been interested in the study of the 

 control of the apple aphis for three or four years, and we were lead to 

 take it up because of the failure of some of our orchardists to obtain 

 protection by the application of nicotine at the cluster cup or pink bud 



