October 1944 r-626
United States Department of Agriculture
Agricultural Research Administration
Bureau of Entomology and Plant Quarantine
AN AQUEOUS SOLUTION OF ETHYLZE DICHLORIDE FOR
FUMIGATION OF JAPANESE BEZTLE LARVAE IN SOIL
By R. D. Chisholm and L. Koblitsky, Division of Insecticide
Investigations,and A. C. Mason and L. W. Coles,
Division of Fruit Insect Investigationc
The effectiveness of an emulsible mixture of ethylene dichloride for the control of immature stages of the Japanese beetle ha recently been reported by Mason, Chisholm, and Burgess (2)17. Infested plant material and soil were treated with 1 gallon of mixture per 100 gallons of water, either by dipping or by surface application, and this treatment was authorized (3) and has been used extensively as a basis of certification of infested plant material under the Japanese beetle quarantine.
The preparation of the diluted mixture involved the making of an emulsion from the specified emulsible mixture and a small quantity of water, which was then diluted with the remainder of the water. Since the emulsible mixture contains a fatty-acid soap, some difficulty has been encountered in a few cases in the making of uniform dilutions owing to the hardness of the only available water. This condition was indicated by the formation of curdy material in the diluted mixture. A method of
preparation has been found which overcomes this objectionable feature.
Since soaps of the nature of that used in the authorized
mixture are converted to water-insoluble compounds by x.i water, attention was directed to other surface-active agents, a larre number of which had been described by Cupples (1). These cozpounds in general overcome the principal disadvantages of fattyacid soaps. A preparation manufactured by the Atlas Powder Conmpany and described by the company,as a polyoxvalkylene derivative of sorbitan monolaurate is soluble in ethylene dichloride and in water.
SUnderscored figures in parentheses refer to Literat are Cited, p. 2.
UNIVERSITY OF FLORIDA
I HI l IIll I lltllllulll
3 1262 09230 4087
An emulsible mixture prepared by dissolving 2-1/2 pounds of "ween 20, as thick -roduct is called, in 97-112 pounds of ethylene dichloride (a-pproximately 1f).--pound of Tweer. 20 per gallon of mixture) makes a clear product that will withstand low temperatures, rnd may be diluted uniformly with hard water.
It is diluted for use in the following manner: One volume
of the emulsible mixture is dispersed by vigorous shaking with an equal volume of water in a closed container for about 1 minute. The resulting uniform emulsion is then diluted at the rate of 1 gallon of this mixture to 200 gallons of water and stirred gently for a few minutes. If the final dilution contains less than enough ethylene dichloride to saturate the water a substantially clear solution will result. If more than enough ethylene dichloride is used the excess will collect on the bottom of the container and may be ignored.
This emulsible mixture in aqueous solution has been successfully used for the control of Japanese beetle larvae. In this dilution the ethylene dichloride content is about the same as that of the diluted mixture previously authorized, and comparative tests have shown it to be at least as effective. Since the active ingredient is in solution, maximum penetration is obtained in soil masses. The use of the aqueous solution here described is now authorized as a Japanese beetle quarantine treatment (4+).
Fmulsible mixtures containing other liquid fumigants such as
dichlorethyl ether or dichloropro-ane-dichloropropylene (DD mixture) have been prepred in a similar manner using Tween 20. Emulsions and aqueous solutions may be prepared from these mixtures as described above, and may be used for the control of various insects.
(1) Cuples, H. L.
1943. Proprietary surface-active agents of possible use in
insecticide preparations. U. S. Bur. Ent. and
Plant iuar. E-607, 40 pp.
(2) Mason, A. C., Chisholm, R. D., and Burgess, E. D.
19i3. Ethylene dichloride treatments for the immature
stages of the Japanese beetle. Jour. Lcon. Ent.
(3) U. S. Bureau of Entomology and Plant quarantine.
!042. Ja:.rnese beetle administrative instructions mollified.
U. S. Dept. Agr., B. Z. P. Q,. 499, Sup. 6, 3 PP.
1943. Treatments used as a basis of certification under
Japanese beetle quarantine. U. S. Dept. Agr.,
B. E. P. !. 529, 3 P-.