134 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



President Glenn W. Herrick: I know there are many comments 

 that could be made on this but we thought it might be best to defer 

 discussion until we have had the paper by Mr. Davis. 



A REPORT ON WHITE GRUB INVESTIGATIONS 



By J. J. Davis, West Lafayette, Ind. 

 (Paper not received in time for publication) 



President Glenn W. Herrick: Now these interesting papers 

 are open for discussion. 



Mr. E. p. Felt: I wish to inquire if any attempt has been made 

 to destroy the white grub in the fall before it goes any depth into the 

 soil? In September I found them mostly a quarter or half an inch 

 below the surface. I wonder if there is any way of destroying them 

 early. 



Mr. J. J. Davis: We have made no effort to destroy them except 

 by fall plowing. It cannot be depended upon to control the grubs 

 except in years when they are transforming to pupae and then fall 

 plowing, especially early plowing will destroy from 75 to 95 per cent 

 of the prepupae, pupse, and recently issued beetles. 



Mr. G. G. Ainslie : I should like to ask Mr. Sanders if he can tell 

 the proportion of sexes that came to light at night? 



Mr. J. G. Sanders: We have no records in Wisconsin regarding 

 the time of appearance of sexes in evening flights. It takes a great 

 amount of work in collecting and determining large numbers of beetles. 

 We were assisted in this work by Mr. Neal F. Howard and Mr. Stewart 

 C. Chandler. 



Mr. T. J. Headlee: The white-grub problem in New Jersey ap- 

 pears to differ from that which has been described. Most of the dam- 

 age has been done to lawns, golf greens and strawberry fields. In 

 none of these places, except in the last, can we use the means of con- 

 trol ordinarily recommended. Because of this fact we have made 

 preliminary trials of soil fumigants. The tests with carbon bisulphide 

 indicated that three quarters of an ounce to the square foot would be 

 sufficient to destroy all the grubs infesting red-shale soil, providing the 

 work were done when the soil was just wet enough to work well and 

 the temperature 70° to 75° F. The experiments in the same series 

 indicated also that one ounce of the carbon bisulphide per square foot 

 would not seriously injure blue grass or white clover under the condi- 

 tions of temperature and moisture above stated. 



Mr. William Moore: I was interested in Mr. Sanders' paper as 

 we have been doing a little white-grub work in Minnesota. The one 



