E-482 June 1939 
United States Departmont of Agriculture 
' Bureau of Entomology and Plant Quarantine 
THE EFFECT ON PLANTS OF METHYL BROMIDE FUMIGATION IN 
JAPANESE BEETLE TREATMENT TESTS; PRELIMINARY REPORT 
By Heber C. Donohoe, Division of Control Investigations, 
and V. A. Johnson, Division of Japanese Beetle Control 
The writers have been investigating the possibilities for the use of 
methyl bromide as a fumigant for the destructior of immature stages of the 
Japanese beetle in greenhouse and nursery stock which moves from withir to 
beyond the boundaries of the area under Federal quarantine against this 
insect. Early in the work results indicated that complete mortality might be 
expected with a fumigation treatment of 2-|- pounds of methyl bromide per 1,000 
cubic feet of space, including the load, for an exposure period of 2-^ hours 
at a minimum temperature of soil and air of 63° F. This indication has since 
been confirmed, and approval has been given for the use of the treatment for 
bare-rooted, potted, or balled plant material, with certain limitations on 
the size of pots and soil balls. 1/ 
Concurrently with the investigations for insect mortality, tests have 
been made to develop information on possible injury to plants as a result of 
this treatment. All tests were made at a dosage of 2j pounds of methyl 
bromide for an exposure period of 2j hours. The lists which follow record 
the observed condition of experimental plants on which information has been 
obtained to April 1, 1939. Other tests are under observation and additional 
ones are contemplated. The data on these will be summarized as soon as the 
accumulated information justifies so doing. 
Individuals using these records as a basis for commercia l trea t ment 
QX plants do so :t their own ris k. The data shown s hould be regarded as 
ex perim ental evidence which may be subj_ect to change with a dditiona l experi - 
mental and prac tica l experience . In no case can the United S tates Dep?rt- 
ment of A griculture or employees of the Depa rtment be held responsible for 
injury to pl ants as a resu lt of fumigation thereof . 
In many cases the number of test plants is too small to be of definite 
experimental value. In other cases cultural conditions both before and 
after treatment may have affected the results obtained. 
1/ B.E.P.Q.~359 (Supplement No. 4), H. Methyl Bromide Fumigation, 
Feb. 15, 1939. Bur. Ent. and Plant Quar., Div. of Control Inv. 2 pp., 
mimeographed. 
