(3 LEAFLET 144. U. S. DEPARTMENT OF AGRICULTURE 



Phosphorus Pastes 



Phosphorus pastes, obtainable at drug stores, are excellent fgr the 

 control of roaches, particularly the larger species and the tropical 

 roach. They are ideal when roaches are not numerous. If the paste 

 is spread on a small piece of flexible cardboard, which is then rolled 

 into a cylinder with the paste on the inside, and with the cylinder Held 

 firm with a rubber band or string, it can be inserted behind boots', 

 etc., without danger of soiling anything; or the cylinders or other con- 

 tainers can be tacked to the back of cabinet drawers, the interior 

 framework or springs of upholstered furniture, or in other situations 

 where they will not be seen. They are especially effective in very 

 damp climates. 



Sprays 



Sprays consisting largely of kerosene oil and pyrethrum extract are 

 excellent for killing roaches. They kill only by contact; hence the 

 roaches must be hit and made wet by the spray. As roaches run 

 rapidly, sprays are not so easily applied to isolated specimens. If 

 possible, the liquid should be sprayed into the hiding places, where 

 more of the roaches can be hit at one time. Much good can be done 

 by applying sprays with a hand sprayer, but the liquid can be intro- 

 duced into hiding places more effectively with a power sprayer. 



Vaporizing Machines 



There are on the market today various makes of machines, operated 

 by electricity, which break up oil-pyrethrum preparations and some 

 other sprays into a fine mist that can be made to fill a room. This 

 mist is very irritating to roaches and causes them to run out of their 

 hiding places into the open, where they die if a sufficient amount of the 

 spray particles comes in contact with their bodies. By repeated appli- 

 cations roaches can be controlled by the spray from these machines 

 in modern tight rooms. Vaporizers have a tendency to drive roaches 

 into surrounding rooms; hence, before using them, all openings to the 

 exterior should be closed so that the roaches cannot escape from the 

 room under treatment. When loosely constructed rooms are in- 

 fested, many roaches are in the surrounding wall spaces, and the irri- 

 tating vapors penetrate these only sufficiently to annoy the roaches 

 and drive many to parts of the building to which they normally would 

 not spread, thus complicating the problem of control. 



i 



U. S. GOVCRNMENT PRiNTISG OFFICE: 1937 



For sale by the Superintendent of Documents. Washington, D. C. - - - - Price 5 cents 



