October I9UU "-626 
 
 United States Department of Agriculture 
 Agricultural Research Administration 
 Bureau of Entomology and Plant Quarantine 
 
 AN AQUEOUS SOLUTION OF ETHYLENE DI CHLORIDE FOR 
 FUMIGATION OF JAPANESE BE3TL2 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 Investigations 
 
 The effectiveness of an emulsible mixture of ethylene di- 
 chloride for the control of immature stages of the Japanese 
 "beetle has recently "been reported "by Mason, Chisholm, and Bur- 
 gess (2)i/ . 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 (j) 
 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 for- 
 mation 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 hard water, 
 attention was directed to other surface-active agents, a large 
 number of which had been described by Cupples (l_) . These com- 
 pounds in general overcome the principal disadvantages of fatty- 
 acid soaps. A preparation manufactured by the Atlas Powder Com- 
 pany and described by the company as a polyoxyalkylene derivative 
 of sorbitan monolaurate is soluble in ethy 1 ene dichloride and 
 in water. 
 
 — ' Underscored firures in oarentheses refer to Literature Cited, 
 P. 2. 
 
UNIVERSITY OF FLORIDA 
 
 - 2 - 
 
 3 1262 09230 4087 
 
 An emulsible mixture prepared by dissolving 2-1/2 pounds of 
 Tween 20, as this product is called, in 97-1 '2 pounds of ethylene 
 dichloride (approximately 1 Z^- pound of Tween 20 per gallon of 
 mixture) makes a clear product that will withstand low tempera- 
 tures, fnd 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 (k) . 
 
 Emulsible mixtures containing other liquid fumigants such as 
 dichlorethyl ether or dichloropropane-dichloropropylene (DD mixture) 
 have been prepared in a similar manner using Tween 20. Emulsions 
 and aqueous solutions may be prepared from these mixtures as des- 
 cribed above, and may be used for the control of various insects. 
 
 LITERATURE CITED 
 
 (1) Cupples, H. L. 
 
 I9H3. Proprietary surface- active agents of possible use in 
 insecticide preparations. U. S. Bur. Ent. and 
 Plant Q,uar. E-607, HO pp. 
 
 (2) Mason, A. C, Chisholm, R. D., and Burgess, E. D. 
 
 19^+3 • Ethylene dichloride treatments for the immature 
 
 stages of the Japanese beetle. Jour. Econ. Ent. 
 36: 73^-737- 
 
 (3) U. S. Bureau of Entomology and Plant Quarantine. 
 
 l n U2. Japanese beetle administrative instructions modified. 
 U. S. Dept. Agr., B. E. P. Q. U99, Sup. 6, 3 pp. 
 
 (4) 
 
 I9U3 . Treatments used as a basis of certification under 
 Japanese beetle quarantine. U. S. Dept. Agr., 
 
 b.'e. p. q,. i>29, 3 ps.