April, '09] JOURNAL OF ECONOMIC ENTOMOLOGY I35 



every bit of color out of the lime-sulfur mixture and a slate colored 

 precipitate was thrown down, showing that there is a pronounced 

 chemical reaction. I do not consider it a safe mixture to use. 



]\Ir. Quaintance : ]Mr. Haywood of the Bureau of Chemistry made 

 an analysis for us and found that the arsenate of lead, when added 

 to the self-boiled wash was changed. Lead sulfide is formed and 

 arsenate of lime. The arsenical is present in the form of arsenate 

 of lime and, of course, might do considerable damage, as there might 

 be more or less uncombined arsenic. Paris green has also been used 

 in combination with the wash. Mr. Scott had some tests of these 

 combined sprays under way in the Ozarks, and I saw the plats my- 

 self, and we were not able to detect the slightest injuiy. 



President Forbes : The next paper will be presented by Mr. San- 

 derson. 



NOTES ON RECENT EXPERIMENTS FOR THE CONTROL 

 OF THE CODLING MOTH 



By E. DwiGHT Saxderson, Durham, N. H. 



Investigations of the life history of the Codling Moth in 1908 add 

 little that is essentially new to the results given this association last 

 year.^ 



Experiments concerning the time and method of spraying have, 

 however, more fully confirmed our previous work and we feel we have 

 established certain points which need emphasis. The results of three 

 years' work also show the necessity for the most careful arrangement 

 of plots and recording of data in order to secure definite results. The 

 details of our results will not be given here, but can be studied in the 

 forthcoming 20th Eeport of the New Hampshire Agricultural Experi- 

 ment Station. 



1. Time of Spraying. — All experiments have shown the first spray- 

 ing just after the petals fall to be the most efficient, giving an average 

 benefit of 82% when used alone. 



Formerly we were advised to spray a week or two after this. Un- 

 der some climatic conditions this may be advisable, but there is little 

 reason for an application for the Codling Moth in New England at 

 that time. The second spraying should be applied when the eggs are 

 hatching, tkree or four weeks after the first spraying. An average 

 of five plots given this spraying only show 72% benefit for the season. 

 Recently there has been a tendency to magnify the value of thorough 



^Journal of Economic Entomology. I, 129-140. 



