10 Farmers’ Bulletin 1246. 
THE PARA-DICHLOROBENZENE TREATMENT. 
In 1915 the Bureau of Entomology began experiments in the use 
of various toxic gases as a possible means of control of the peach 
borer. This work, carried out by Mr. E. B. Blakeslee and con- 
tinued for several seasons, covered a wide range of soil, climatic, 
and seasonal conditions, and demonstrated the usefulness for borer 
control of para-dichlorobenzene and the impracticability of using 
carbon disulphid, sodium cyanid, and certain other materials. 
Many experiments with para-dichlorobenzene showed that when 
properly used it is uniformly effective in killing a high percentage 
of the borers without injurious results to trees 6 years of age and 
Fia. 9.--Adult female of the peach borer. Enlarged. 
over. The results were published in United States Department of 
Agriculture Bulletin No. 796 (Oct. 21, 1919), and resulted in the 
prompt adoption of the treatment by many commercial peach 
growers. There has now been accumulated a sufficient body of 
experience, based on large-scale commercial use, and further experi- 
ments by the bureau and others, principally the New Jersey Agri- 
cultural Experiment Station, to show that a practical economic 
method of control has been found for this heretofore almost invul- 
nerable pest. 
PARA-DICHLOROBENZENE DESCRIBED. 
Para-dichlorobenzene, for which the abbreviated name ‘‘paradichlor” 
is suggested when referred to as an insecticide, is a white crystalline 
substance having an etherlike odor, and vaporizing readily under 
