February, '19] journal of economic entomology 



Plate 4 



Mncliiiu's for Applying I>i(|ui(l Hyrdocyanic Acid in Kiold Fumination; 1, PliiiiKor 

 type used almost cxolusively during 1918; 2, (iravity t\i)e used durinti 1917 and 

 to a limited extent during 1918. 



