THE WAX MOTH AXD ITS CONTROL 



* 



strips of gummed paper (fig. 5). Three ounces of the crystals to a 

 stack of five 10-frame hive bodies may be sprinkled directly on the 

 top bars of the frames, as in figure 5. or preferably put on a piece 

 of paper or cardboard laid on the top bars. The cover should then 

 be put tightly in place. Since the gas is nonpoisonous and not dis- 

 agreeable, treatment may be made in ordinary storage, it being un- 

 necessary to take the infected material out of doors. At intervals 

 during the storage season the covers of the stacks should be raised, 

 and if no crystals are still present more should be added. 



Figure 5. — Supers loaded with comb ready fur fumigation. The joints are 

 sealed with gummed paper tape, and the crystals of paradichlorobenzene hare 

 been sprinkled heavily over the top bars. 



Paradichlorobenzene is most effective at temperatures above 70 c F. 

 and volatilizes more rapidly as the temperature rises. Stored materials 

 should be inspected at intervals of 2 or 3 weeks, depending on the 

 temperature of the storehouse and the prevalence of moths. 



CARBON DISULFIDE 



Carbon disulfide has been a standard fumigant for wax moths and 

 similar insects until recently, and with proper precautions it is still 

 considered satisfactory. The commercal product is a yellowish, 

 somewhat oily liquid, which changes readily at ordinary temperatures 

 into an ill-smelling gas. The liquid is about one-fourth heavier than 

 water, and the gas is heavier than air. It is highly inflammable, 

 and the vapor is explosive when mixed with air in certain pro- 

 portions; therefore, this chemical must not be handled around 

 fire of any kind. At certain concentrations it can be ignited by 



