Fumigation 
A roach infestation can be destroyed immediately by fumigation. 
However, this method has several limitations. Loosely constructed 
buildings cannot be fumigated because the fumigant gas escapes too 
rapidly. It is an expensive operation and premises within congested 
or commercial areas are likely to become reinfested in a short time. 
Moreover, in such areas fumigation is especially dangerous. It is 
restricted in some localities and should be done only by a professional 
pest-control operator. Fumigation is seldom used for roach control 
now that effective residual insecticides have become available. 
Boric Acid and Borax 
Finely powdered boric acid or borax can be used to combat roaches. 
They are less poisonous to man than are some other insecticides, but 
also less effective and very slow acting against roaches. These ma- 
terials are sometimes mixed with ingredients attractive to roaches and 
compressed into tablets to be used as bait. ‘The powders or bait tablets 
may give satisfactory results when used in offices or other places where 
there is little food for roaches. 
Phosphorus Paste 
Phosphorus paste can be used against all the domestic roaches except 
the German cockroach. It is especially effective in very damp cli- 
mates. The paste should be spread on small pieces of cardboard, 
which can then be rolled into cylinders with the paste inside and 
fastened with a rubber band or string. ‘The cylinders should be placed 
where children and pets cannot reach them, where they will not be 
seen, and where things will not be soiled or contaminated with the 
paste. When brown-banded roaches are present, insert the cylinders 
behind books, place them on closet shelves and in framework of up- 
holstered furniture, or tack them to the back of cabinet drawers. 
U. S. GOVERNMENT PRINTING OFFICE: 1950 
OO 
For sale by the Superintendent of Documents, U. S. Government Printing Office 
Washington 25, D.C. - Price 10 cents 
