LIBRARY 
rATE PLANT BOARD 
August 1948 E-737, Revised 
United States Department of Agriculture 
Agricultural Research Administration 
Bureau of Entomology and Plant Quarantine 
EFFECT ON PLANTS OF DDT APPLIED TO SOIL FOR 
TBE DESTRUCTION OF JAPANESE BEETLE LARVAE 1/ 
By Walter E. Fleming 2/ 
Division of Fruit Insect Investigations 
A very small amount of technical DDT (1 part to 32,000 parts of 
soil by weight) has been very effective against larvae of the Japanese 
beetle in cultivated land and in turf. The use of technical DDT for 
the treatment of beds, plots, and potting soil in commercial nurseries, 
in order that plants with soil about their roots may be shipped outside 
the area quarantined because of this insect, was authorized March 21, 
194-6. To facilitate the proper distribution of this small amount of DDT 
it is specified that each acre of beds, or plots be treated with 250 
pounds of a dust containing 10 percent of DDT, or with $0 pounds of a 
water-dispersible powder containing 50 percent of DDT in 1,000 gallons 
of water, and the material then mixed by cultivation with the upper 3 
inches of soil. It is specified that 3 pounds of a 2-percent dust be 
intimately mixed with each cubic yard of potting soil. 
Preliminary experiments were begun in 1944 at Moorestown, N. J. , 
to determine whether various plants could be grown without serious 
injury in soil treated with the authorized amount of technical DDT. 
In these tests an equal number of seeds or plants in treated and in 
untreated soil were grown side by side under the same conditions. When 
the general development, color, bloom, and yield of the plants were 
about the same in treated and untreated soil, it was considered that 
the DDT had not seriously affected the plants. In view of the 
favorable results obtained with some of the vegetables, annual flowers, 
grasses, and a few nursery plants in these preliminary tests, similar 
tests were conducted at five commercial nurseries in 1945 and in more 
than fifty establishments in 1946 and 1947. In addition to these 
tests, after the treatment was authorized, several kinds of plants 
were grown on a large scale at the commercial establishments. 
1/ This revision brings the information up to January 1948. 
2/ The author is indebted to his associates at the Japanese Beetle 
Laboratory, Moorestown, N. J., to members of the Division of Japanese 
Beetle Control, and to the various commercial establishments for their 
cooperation in this investigation. 
