- 40 - 
A dust containing 2,5 parts of derris and 97.5 parts of hydrated lime 
gave 100-percent control in 5 daj^s when the foliage was first dipped 
in water and the dust then blown on. Derris in spray form required 5 
pounds per 100 imperial gallons of water to rroduce 100-percent mortal- 
ity, while nicotine sulfate (40 percent), \fl pint to 100 gallons, gave 
control. In all tests derris ■ 
nicotine. 
the same control. In all tests derris was much slower in action than 
x . . j. 
McDaniel ( 186 ) in 1928 wrote that the potato aphid was controlled by 
Derrisol. 
Derris dust failed to give satisfactory control in the field. — Walker 
and Anderson ( 298 ); also reported by Cory (277) in 1935. 
Manschke (191) in 1937 reported that 96.5 percent of red and green 
potato aphids on tomato were killed by a spray consisting of 2 pounds 
of derris powder (4 percent rotenone) per 100 gallons of water plus about 
3/4 ounce of coconut-oil soap (40 percent dry soap) per gallon. 
The rotenone preparations Cvbor, Fiagron, and Kubatcx and derris 
were effective. — Massachusetts Agricultural Experiment Station ( 194 ) 
in 1937, 
Pepper (224) in 1937 reported on the control of pink and green 
aphids, M. solanifo lii, on tomatoes in New Jersey. Nicotine was more 
effective than derris or pyre thrum. The estimated results of pyrethrum, 
derris, and mixtures of pyrethrum-derris dust, as compared with 4 percent 
nicotine dust, are tabulated as follows: 
Treatme nt Estimated 
control 
( Percent ) 
Pyrethrum- talc (25:75) 50 
Derris dust (0,75 percent rotenone) 35 
Pyrethrum 50 pounds, derris root (4 percent 
rotenone) 20 pounds, and talc 30 pounds 70 
A commercial mixture of derris and pyrethrum 
(0 3 5 percent rotenone and 0.2 percent pyrethrins) 60 
Four percent-nicotine dust 95 
Approximately 30 to 35 pounds of the above mixtures was applied per 
acre. Oils impregnated with pyrethrum and derris extract were sprayed 
from an airplane. Poor kill (about 25 percent) was obtained from the 
application of regular kerosene 10 gallons, concentrate of pyrethrum plus 
derris 1 gallon, and highly refined petroleum distillate 10 gallons plus 
concentrate of pyrethrum-derris 1 gallon. There was little difference 
between the treated plots; and, since the percentage kill of aphids was 
so low and time was limited, actual counts were not made. The airplane 
sprayer did not break up the spray as fine as was expected. Poor dis- 
tribution of the fog or oil particles was, no doubt, a part of the cause 
of 000 r results. 
■1 ■ i \ mmmmmmmmmmBmmmmmmmmmmmmmmmmmmmmfmm 
