April, '16] DAVIS: WHITE GRUB INVESTIGATIONS 261 



plant was creosote. Grubs apparently avoided the region where 

 corn seed which had been dipped in creosote had been planted and 

 did not attack the young corn which sprouted from it. These results, 

 however, had not been anticipated and have not yet been followed 



up- 



In connection with the insecticide experiments it should be stated 

 that of the sixty-three larvse which were reared in the flower pots, 

 but on which no experiments were tried, ten died of bacterial or 

 other diseases within forty days. This gives an average mortality 

 in the check pots of 15.9 per cent for the six weeks. 



In conclusion, it may be stated that the results in connection with 

 temperature and the nature of the food supply seemed most significant. 

 It is also of interest to note that white grubs are not immune from 

 arsenical poisoning as wireworms have been said to be, and that there 

 is a possibility that repellants will prove of some value in controlling 

 them. 



A PROGRESS REPORT ON WHITE GRUB INVESTIGATIONS^ 



By John J. Davis, U. S. Bureau of Entomology, West Lafayette, Indiana 



The white grub {Lachno sterna) investigation was begun at the 

 Lafayette Station of the federal Bureau of Entomology in 1911 and 

 has been one of the major problems of this station continuously since 

 that date. The report herewith presented is very brief and but an 

 outline of some of the more important studies made by the writer or 

 under his direction and is given at this time as a guide for those in the 

 federal Bureau as well as station and state entomologists who are 

 cooperating with us in this large problem and for others who are or 

 may have occasion in the near future to take up this problem. 



The plan and scope of our studies are comprehensive in the broadest 

 sense, including not only life-histories and habits of the different 

 species of Lachnosterna and means of control in this section of the 

 United States but studies in the embryology, the distribution of species 

 in all parts of the country in relation to soil, timber, farming methods 

 and other environmental conditions, destructive broods of different 

 species, systematics, etc., as well as thorough studies of the related 

 genera, with especial reference to the economic importance and life- 

 history of these related genera and means of distinguishing the larvse 

 of the different genera and of the different species in each genus. It is 

 hoped eventually to have worked out the life-history and habits of 

 every species of Lachnosterna and species of related genera for the 

 various localities where each mav occur. 



Published by permission of the Chief of the U. S. Bureau of Entomology. 



