- 22 - 
same concentration diliydrorotenpne killed from 65 to 75 percent. — Tan der 
Laan ( 177 ) In 193:;. " 
Eta'Dlissement-p Rotenia in 193^, in a. letter to R. C. Roark, stated 
that this species is repelled by a proprietary product containing 12 "oer- 
cent of cube of 6 percent rotenone content. 
Hyalopterus arundinis (F.) (H. pruni (F.)), the mealy plum aphid 
Garman ( ll6 ) in 1928 reported experiments made in Connecticut with 
insecticides offered as substitutes for nicotine sulfate. Cne of the 
commercial preparations of derris was tried in I927 against the mealy 
plum aphid and showed good killing power. It vas evident that soap or 
casein lime was needed in combination. The product investigated did not 
mix well with lime-sulfur solution of winter strength. Tests with commer- 
cial preparations of derris and pyrethrum against the mealy plum aphid 
g ve the following results: 
Material Dilution Mortality 
Percent 
Derris ^reparation ----- 1 11.. to 100 gal. - - - - 88. 3 
Do - r 2 lb. to 100 gal. 97.6 
Fyrethrura soap - - - - - 53 11. to 100 gal. - - - - 9-.U 
ITicotine sulfate l" lb. to 100 gal. 92.2 
Chec 1 :, no treatment ----- — ____ q 
Derris 01 
1:6,250 were e 
or rotenone suspensions at a concentration of 1:5,000 or 
ffective. — DeBuss'y et al . (^0) in 1935. 
Hystercneura seta.riae (Thcs.), the rusty plum aphid 
Farrar (98) in 193 6" reported that extracts of pyrethnim, derris, 
or cube '-'ere not so efficient against H. setariae as was nicotine mixed 
with oil emulsion. The addition of soap increased the killing nower of 
an oil containine," such extracts, "but not enough to warrant the added cost 
of the extracts. 
Macrc siphoniella, s ar.-'oorr.i (Gill.), the chrysanthemum aphid 
Derris dust was effective. — Mclndoo and Si even ( 188 ) in I92U. 
Ginsburg and G-ranett ( 12U ) in 1935 reported res. Its with a commer- 
cial acetone extract of derris. This extract contained 5 percent of 
rotenone and 16 percent of total extractives. About 2,000 chrysanthemum 
plants infested with M. sanborni were sprayed with the commercial acetone 
extract of derris at dilutions of 1/3 pint to 100 gallons of water and 
0.2 percent of coccnut-oil soap. Observations 2 days later showed practi- 
cally 100-percent- kill of this insect. 
Macro si~ohum liriodendr i (Men.), the tulip tree aphid 
Mclndoo, Sievers, and Abbott ( I89 ) in 1919 reported that the alco- 
