- 61 - 
Ginsburg (121) in 1933 stated that -when only aphids are present, 
1/2 pint of an acetone extract of derris (5 percent rotenone, 20 percent 
total extractives) to 100 gallons of water, containing about 0.2 5 percent 
of coconut oil soap, is sufficient, 
Gnadinger ( 128 ), in the first edition -of his hook, "Pyrethrum 
Flowers," concluded that the on] r it c ] a Ivantage in adding rotenone 
to pyrethrum sprays is to increase bhe toxicity to aphids, Unpublished 
work tr Ginsburg is cited which indicates that rotenone is rore toxic 
than the pyre thr ins tc aphids, 
Hamilton (136) in 1933 stated that derris and cube powders have a 
distirct repellent effect anc si [Yrrni -tin:- effect against certain 
insects, such as plant lice. 
Spoon (250) in 1. '0, r oorted sprays of derri: powder with half its 
weight of soap and red: tone ensions made by pouring an acetone solu- 
tion into '.rater plus 0.1 percent Agral or 0,05 percent Lethalate as a 
spreader (rotenone concentrations 1:2, 50C and 1:5,000, respectively) to bo 
effective agaj ] : aphids in holla: d. 
Benkert and Company, Inc., oh her: York, N, Y. , in March 1934 stated 
in advertising literature that derris dust is effective against plant lice. 
An alcoholic extract of derris plus soap was effective against 
plant lice. --Bock (15) in 1934, 
The lubber Service Laboratories, Inc. (235), in 1934 reported that 
a spray containing 7 ports of derris resin, 35 parts of dry Aresco, and 
60 parts of pine Til (or oleic acid) is effective against aphids at 1:800. 
The Alabama Polytechnic Institute (3) in 1955 reported that derris 
dust alone is not very effective in controlling plant lice hut -alien mixed 
with sulfur is of soae value in repelling these insects. 
DeLussy et al. (32) in 1935 reported that aphids can readily be 
controlled by spraying with a suspension of dsr.ris having a rotenone 
concentration of 1:10,000 or by spraying .ltd a pure- rotenone suspension 
containing rotenone at a concentration of 1:5,000. During 1955 dehussy 
associates usnd derris dusting powders against ;reon and black 
Ids with the following results: 
