- 5 - 
Fulton and Howard (27, 28) in 19 38 reported on the effect. on 
the toxicity to plant bugs of adding oil to derris and other insecti- 
cides. Derris powder containing 4.5 percent .of rotenone and 14, 
percent of total.. extractives (carbon tetrachloride) was added to 
emulsions of tung, tea seed, corn, cottonseed., linseed, peanut, olive, 
and soybean cils, and also to heavy petrolatum oil, and was tested 
against squash bugs and the large milkweed bug (Oncopeltus fascia tus 
(Dall.)). ~~~ r ~ 
The oil emulsions with derris were prepared with the following 
quantities: Technical sodium lauryi sulfate, 0.1 gm. (0.3 gm. in some 
tests); water 5 cc, oil 2 cc. (4- cc. for 2-percent emulsions); derris 
0.44 gm. (for spray of 0.01 percent rotenone content); and water to 
make 200 cc, unless otherwise noted. The combined sodium lauryi sulfate 
and water v/as stirred with an electric mixer until the former was com- 
pletely dissolved. The measured quantity of the oil was then slowly 
added and the Mixture was stirred for several minutes until an emulsion 
obtained. The derris was introduced and the mixture again stirred. 
Water was then added to obtain the desired dilution. The derris in 
. acetone was prepared by mixing 0.555 gm. of derris with 5 cc. of acetone 
and allowing it tc stand for 24 hours before adding the other materials. 
The triethanol amine oleate used in the derris-acetone emulsions was ma.de 
by stirring together equal volumes oi triethanolanu ne and oleic acid in 
the mixer. It was used at the rate of 0.2 cc. to 200 cc. of the final 
solution. 
The results obtained with the squash bug may be summarized as 
follows: The tonicity of derris, nicotine, nicotine sulfate, and anabasine 
sulfate was markedly increased by the use of oils, especially peanut oil. 
Also, the toxicity oi' derris was greatly increased when acetone was added 
to the powder 24 hours before use, and still further increased when peanut 
oil was used. Freshly prepared derris extract was very effective. The 
vegetable oils increased the toxicity at much greater degree than the 
mineral product. 
The mi Ikweed bug is not so resistant to insecticides as is the 
squash bug, and it is relatively more susceptible at the higher humidity. 
In the few tests with the milkweed bug, -mineral oil was practically as 
effective as the peanut oil, but this was not the case in tests with 
the squash bug. However, all the cils increased the toxicity of derris. 
Foliage tests in the field on five varieties of half-grown 
squash plants indicated that two applications of sprays c i Ling 
derris (0.015 percent rotenone) and 1 percent of one o£ the following 
oils were not injurious to the plant: Olive, peanut, teaseed, and 
petrolatum. 
A cube or derris dust (l percent rotenone) centred led the nymphs 
and partially controlled the adults. — Haude (38) in If 39. 
