238 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 14- 



Just one more point I have in mind here, and that is really an entomo- 

 logical problem and some day at the entomologists' meetings when 

 interest lags, we might start the discussion. It is very doubtful that 

 nicotine functions entirely in its volatile condition. It is more likely a 

 true contact posion and does not function as a gas. That is all I want 

 to say now; I don't want to start anything at this time. 



Mr. N. J. GiDDiNGs: It was suggested by Dr. L3rman, before I gave 

 my paper, that a word as to the activity and interest in regard to this 

 project might not be out of place. Last year the Advisory Board of 

 American Plant Pathologists asked me to act as leader in an endeavor 

 to encourage cooperative work on the dusting project. In this connec- 

 tion a general outline or plan was sent to twenty-six states. Twenty- 

 three of those replied, indicating that the interest was great. Eighteen 

 states were strongly favorable toward further work in connection with 

 dusting, and at least nine states reported experimental work during the 

 season. Seven of them have already turned in data to me. These 

 statements relate particularly to the pathological side. I might add 

 that the outline was not sent generally to the South because it was rather 

 late in the season. This is merely an indication of the interest that the 

 dusting problem has for the whole country. 



President Wilmon Newell : We have undoubtedly gained a great 

 deal of good out of these discussions. 



Adjournment. 



ARSENIC FOR GRUB-INFESTED SOILS 



By J. F. Illingworth, Gordonvale, near Cairns, North Queensland 



For some time we have been experimenting with poisons applied to 

 the soil for the control of white grubs, since, as is well known, these pests- 

 are a serious menace to the growth of sugar-cane, particularly on the red 

 volcanic soils in North Queensland. 



Naturally our earlier experiments were in the laboratory, where the 

 poisons were tried in small pots of soil. This was done by mixing the 

 two together thoroughly before introducing living grubs, which by their 

 natural process of ingesting quantities of soil inevitably absorbed some 

 of the poison. Alost satisfactory results were obtained with the ordin- 

 ary crude white arsenic (arsenious acid). 



By using a liberal sprinkling of the arsenic through the soil we found 

 that the grubs all succumbed in from one to four days, and this same result 

 was secured with each repetition of the experiment. 



