50 BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE [July-Sept. 
B. P. Q.-359 (Supplement No. 1) August 23, 1935. 
SUPPLEMENTAL INSTRUCTIONS TO INSPECTORS ON THE TREATMENT OF 
NURSERY PRODUCTS, FRUITS, VEGETABLES, AND SOIL FOR THE JAPANESE 
BEETLE 
Section II of Circular B. P. Q.-359 entitled " Instructions to Inspectors on 
the Treatment of Nursery Products, Fruits, Vegetables, and Soil for the 
Japanese Beetle ", is supplemented as follows : 
II. Treatment of Soil About the Roots of Plants 
F. PARADICHLOROBENZENE TREATMENT 
The method outlined herein may be employed as a basis of quarantine 
certification under regulation 6 of Quarantine No. 48, revised. 
Plants which may be treated in accordance with instructions given below: 
Azalea hinodigiri. 
Azalea amoena. 
Azalea obtusa kiusiana. var. Coral Bells. 
Azalea kaempferi vars. Othello, Fedora, Salmon Beauty, and Cleopatra. 
The use of paradichlorobenzene in treating plants other than those listed 
above is not recommended. If, as a result of further experimental work, 
its use can safely be extended to include other species and varieties of azaleas 
or other plants these instructions will be further supplemented. 
Material. — Paradichlorobenzene. A technical or c.p. grade should be used. 
If the chemical is lumpy it should be ground into small-sized crystals before 
being used. 
Condition of soil. — The soil with which the paradichlorobenzene is mixed 
should be moist, friable, and low in organic matter; free from lumps, stones, 
and debris; and sifted through a half-inch mesh screen prior to mixing with 
the paradichlorobenzene. 
Condition of plant ball. — The plant balls should be moist but not wet, and 
not over 8 inches in diameter. If the soil is wet the treatment will not be 
satisfactory ; if the soil is dry the plants may be injured during the treatment 
Season. — Treatment can be made at any time between October 1 and May 1, 
providing the proper temperature conditions can be obtained. 
Dosage. — With soil balls or potted plants up to 6 inches in diameter, use 
paradichlorobenzene at the rate of 10 pounds per cubic yard (or 6 ounces 
per cubic foot) of mixing soil. For soil balls or potted plants larger than 
6 inches and up to 8 inches in diameter, use paradichlorobenzene at the rate 
of 20 pounds per cubic yard (or 12 ounces per cubic foot) of mixing soil. 
Temperature requirements. — The treatment should not be applied unless the 
temperature of both the treating soil and the soil ball is 50° F. or above. 
During the period of treatment the temperature should not be allowed to fall 
below 50°, and in order to prevent injury to the plants it should not go 
above 65°. . 
Application. — The treating soil should be mixed immediately before being- 
used, as follows : Spread soil in a thin layer, add paradichlorobenzene at the 
proper concentration, and mix thoroughly by means of shovel, rake, or fork, 
turning it at least three times ; spread layer of treated soil on hard surface 
in box, bin, on the floor, bench, or other suitable surface. Remove the pots 
from the potted plants, or the burlap from the balls of the field-grown plants, 
and place the plants in a row with the soil balls about 1 inch apart, filling 
the spaces between the plants with treated soil, and covering the balls to a 
depth of 1 inch with the treated soil. Place approximately 1 inch of soil 
against the row of plants and repeat the operation until all the plants are 
in place. 
Period of treatment. — The plants must be left undisturbed for a period of 
5 days. During this time they should not be watered. At the completion 
of the treatment period, the plants should be removed from the treating soil 
and they may then be watered. The treating soil should not be used a second 
time for treating purposes. 
Handling after treatment. — Plants can be handled after treatment by the 
usual nursery procedure. Care must be taken to avoid reinfestation. 
Lee A. Strong, 
Chief. Bureau of Entomology and Plant Quarantine. 
