residue on the treated surface 

 The residue does not keep cock- 

 roaches out. but those that come 

 in contact with it are killed. A 

 single treatment in the right places 

 gives protection for several weeks. 

 A liquid insecticide is often the 

 best for use in the home. A dust 

 or water-base spray may be used 

 when there is danger of fire from 

 oil-base liquids. Both a liquid and 

 a dust may be used when cock- 

 roaches are abundant, difficult to 

 control, or firmly established. 



For restricted-use 



Chlorthion and Dipterex are ef- 

 fective in controlling roaches, but 

 their uses are restricted. 



Chlorthion. may be used any- 

 where except in homes and in 

 places where milk is processed or 

 stored. It should be applied as a 

 1- or 2 -percent spray or paint. 



Dipterex should be used only by 

 pest-control operators. It should 

 be applied in a 1 -percent water 

 spray. 



Application 



Spray 



Apply a liquid insecticide with 

 an ordinary household plunger- 

 type sprayer that produces a coarse 

 spray. 



If large areas are to be treated, 

 compressed-air sprayers, power 

 sprayers, or other special equip- 

 ment may be used. The sprayer 

 should deliver a fairly coarse mist 

 that will wet the surface being 

 treated. If the mist is too fine, it 

 will float away in the air. Apply 

 enough spray to moisten surfaces 



Oriental cockroach: Above, female: below, 

 male. [\ X A times natural size. 



thoroughly, but not so much that 

 the liquid begins to drip or run. 



A paintbrush may be used for 

 applying the liquids in cracks or 

 along baseboards. 



Dust 



Apply a dust insecticide with a 

 puff duster of the bulb, plunger, or 

 bellows type. Blow the dust into 

 hiding places that are hard to 



