February, '17] DAVIS: LACHNOSTERNA FOOD VALUES 41 



to carry on a spraying test with Bordeaux mixture, to which was added 

 a large amount of Ume — 60 to 80 pounds to 100 gallons of the mixture. 

 In this connection it is of interest to note that the spraying did not 

 apparently deter the insects from ovipositing. 



Vice-President G. A. Dean: If there is no further discussion, we 

 will listen to the next paper by Mr. J. J. Davis. 



A CHEMICAL FEEDING ANALYSIS OF WHITE GRUBS AND 

 MAY-BEETLES (LACHNOSTERNA) AND ITS ECONOMIC 



APPLICATION! 



By John J. Davis, West Lafayette, Indiana 



The practice of hogging off corn, thereby saving the labor and ex- 

 pense of harvesting and marketing the crop and producing more pork 

 from the crop, is becoming a common farm practice and the value of 

 this procedure has been demonstrated by federal and state investi- 

 gators. However, the additional value and utilization of hogs for 

 the destruction of soil-inhabiting insect pests, more especially white 

 grubs and cutworms, has been given but little attention and seldom 

 consistently applied, although pasturing hogs in grub-infested fields 

 has been more or less practised for the past hundred years. 



Their fondness for white grubs is well known, being evidenced 

 wherever unringed hogs have been turned into pastures and their 

 utilization for the eradication of grubs has been excellently shown by 

 Dr. S. A. Forbes who reports^ the destruction of 99 per cent of the 

 grubs in a ten-acre, badly infested cornfield after being pastured for 

 twenty-seven days with 100 pigs and 8 sows. 



Notwithstanding these demonstrations, farmers have been slow in 

 making use of hogs for the control of grubs, largely because their fields 

 are not hog-tight and it therefore becomes necessary to prove the 

 practicability and profitableness of the practice beyond the simple 

 eradication of insect pests. Consequently a chemical feeding analysis 

 of the grubs and May-beetles was made by Messrs. C. Cutler, J. H. 

 Roop and M. S. Libbert, through the cooperation and courtesy of Mr. 

 W. J. Jones, state chemist of Indiana. 



The analyses as furnished us by Mr. Jones, which were made from 

 one- and two-year-old grubs and recently matured adults, respectively, 

 collected in the fall of 1916 behind plows, together with the analysis 

 of dent corn as given by W. A. Henry ,^ follow: 



1 Published by permission of the Secretary of Agriculture. 



^ On the Ufe-history, habits and economic relations of the white grubs and May- 

 beetles. Bui. 111. Agr. Expt. Sta., No. 116, Aug. 1907, p. 478. 

 3 Feeds and Feeding, 1910. 



