April, '19] GUYTON: CHRYSANTHEMUM GALL MIDGE 165 



Mr. E. N. Cory: I might say that we worked on the box leaf 

 midge some years ago, and in a small way. We were unable to get any 

 results with nicotine sulphate. 



Mr. E. p. Felt: Was the spraying at the time when you would 

 catch the pupae as they were pushing out of the galls? They have 

 just about the same habit. 



Mr. E. N. Cory: It was an attempt to get penetration and to 

 kill the larvae. 



President E. D. Ball: We will call on Mr. Sasscer for a r6sum6 

 of Mr. Woglum's paper on "Recent Developments in Fumigation with 

 Liquid Hydrocyanic-acid." 



Mr. E. R. Sasscer: I am very sorry that you have not time to 

 hear this paper of Mr. Woglum, because it shows the latest develop- 

 ments of hydrocyanic-acid gas fumigation in California. You are all 

 familiar with the old pot method where sodium cyanid is placed in the 

 dilute sulphuric acid. 



[See p. 117-123 of February issue for text of this paper. Ed.) 



Mr. W. E. Britton: I would hke to ask Mr. Sasscer if he has 

 tried this out in greenhouse fumigation. 



Mr. E. R. Sasscer: No, I have not tried it out. I hope to give 

 it a test as soon as a suitable shipping container is found. 



Mr. p. J. Parrott: What is the effect on the valves or the metal 

 parts of your machine? We find that the valves give way after the 

 third year of use. 



Mr. E. R. Sasscer: I am unable to answer this question since 

 all of this work has been under Mr. Woglum's supervision. 



Mr. T. J. Headlee: I would hke to ask the speaker if he has 

 used the ordinary soda bottle, with the CO2 gas? 



Mr. E. R. Sasscer: It is understood that I have not used liquid 

 hydrocyanic-acid and that all of the work referred to was done in 

 California under Mr. Woglum's supervision. I am told that an appar- 

 atus working on practically the same principle as a soda bottle can be 

 satisfactorily used. 



Mr. W. H. Goodwin: Have they in any case used the oxygen or 

 hydrogen steel drums? 



Mr. E. R. Sasscer: I do not know. All of this work has l)oen 

 done in California. 



Mr. W. H. Goodwin: I know that in our cvaiiidc work wIhmc we 

 use the liquid cyanide, all brass connections and valves will soon be 

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