& 



JOURNAL OF AGRICULTUEE OF P. R. 



The following table shows the general trend of all the experiments 

 conducted with this substance: 



Experiment VIII. — Experiment with Vaporite Against the White Grubs. 



How applied 



Hole in center of stool 



When 

 applied 



.June 8 

 Mav 23 



When 



examined 



June 14 

 May 27 



No. of grubs found 



Alive 



G 



8 



17 



14 



20 



Dead 





 

 1 

 

 



The above results would tend to show that this substance had 

 no effect whatever on the grubs. It is possible tliat the material 

 had deteriorated somewhat before application. 



SOIL INSECTICIDES AND DETERRENTS. 



Under the heading of soil insecticides and deterrents have been 

 grouped experiments with a large number of different chemicals and 

 manurial agents in their relation to the control of the white grub. 

 No special order lias been observed in presenting them other than 

 to arrange them as logically as possilile. 



Experiments with lime and various chemicals and chemical compounds mixed 

 with lime. 



Experiment IX. — Experiment with Ammoniac ' and Lime Against the White 



Grub. 



'Sal ammoniac (ammoiiiuin chloride). 



As may be seen by the al)0V(' tal)h'. the animoiiiiic and lime lin.i 

 little or no effect on tlie wliitc gnibs. 



