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The best results were obtained with materials in which rotenone 
was the active ingredient. The most extensive tests were carried on with 
Serrid, a derris extract with a rotenone content of 5 gm. per 100 cc. 
A 0.25-percent solution of powdered Ivory soap in combination with Sen id 
gave nearly as high kills in the insectary as a 2-percent-soap solution 
in combination rath Serrid in the field. Also, Serrid alone and the soap 
alone, even at weaker dilutions, gave higher kills in the insectary than 
in the field. The addition of soao to the Serrid greatly increased its 
effectiveness. Practical field control of adult harlequin bugs on young 
kale has been obtained with 1 uart of Serrid to 200 parts of a 1-pcrcent 
solution of powdered Ivory soap, applied under 150 to 200 pounds pressure. 
The Serrid and soap combination should be used as soon as it is mixed 
because rotenone deteriorates rapidly in the presence of soap, and the 
insects must be thoroughly covered with the spray material in order to 
obtain satisfactory control. 
hoxon Plant Spray was about half as toxic -as the Serrid and Soap 
spray. Ku-ba-tox, a rotenone dust, did not give satisfactory control, 
possibly because of its low rotenone content. 
Preliminary tests with Super Agricultural Spray, a derris product, 
at the rate of 1 part to 200 parts of ".voter, and with powdered air- 
floated derris root with a 4-percent-rotcnone content, used at the rate 
of 1 part to 2 and 4 parts of an inert carrier known as Inert C (a clay), 
have given satisfactory control both in the insectary and in the field. 
However, these tests were so limited in number that further experiments 
must be conducted under varied conditions before their use ean bo generally 
recommended. Sentone and Dcrrax, two rotenone dusts, were not quite so 
effective in insectary tests as was the powdered, air-floated derris- root 
dust. 
White and Brannon (97) in 1933 reported the results of tests made 
with many insecticides to determine their effectiveness against the harle- 
quin bug. Derris extract was tested at dilutions ranging from 1:200 to 
1:1,200 with una without soap (0.5, 1, or 2 percent) and with whale-oil 
soap. Derris extract was used in a small series of experiments with white* 
oil emulsion, summer-strength oils, and tannic acid, and with spreaders. 
Several of these materials gave excellent results in cage tests, 
but were found to be inefficient under field conditions. The best results 
were obtained with derris extract (containing rotenone as the active in- 
gredient and a spreader or wetting agent) at a dilution of 1:200. This 
may be prop; red as fellows: Use 2 quarts of derris extract in 100 gallons 
of water or, in smaller quantities., 2 ounces (4 table spoonfuls) in 3 
gallons of water. Measure the quantity of derris extract required to moke 
a 'iv;n quantity o r finished spray, and thoroughly dissolve this in a 
little water. Then add the dilute derris extract to the quantity ci water 
needed for the finished spray. Agitate the mixture and apply immediately. 
Fix only sufficient spray for immediate use. It should be borne in mind 
that only those insects actually hit ^oy the spray are killed. Thorough- 
ness of application is of prime importance. Preliminary tests indicate 
that commercial dusting powders containing approximately 0.5 percent of 
rotenone are also of value in controlling the harlequin bug. 
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