m ^y - 
The Louisiana Agricultural Experiment Station (184) in 1037 recom- 
mended derris diluted with sulfur, tobacco dust, clay, or talc to e rote- 
none content cf 1 percent for the control of the turnip aphid* 
The Texas Agricultural Experiment Station ( 266 ) in 1937 reported 
that the standard spray formula (ificot^ne sulfate plus penetrol) was 
superior to the rctenone-pyreth rum-sulfur combination in dust Torn, and 
remained more effective for a week or 10 days after the applications were 
made, 
Harrison ( 142 ) of the Bator: Route, La., laboratory, reported in 1939 
that tests with 20 different dust mixtures, involving the use of dilutions 
of 1,0 and 0.5 percent of rotenone with various diluents and conditioners^ 
resulted in no significant difference'.-: in yield between the treatments. 
This indicates that the present standard recommendation for tur hid 
control ( rotencne-dust mixture containing 1-porcent of rotenone with equal 
parts of tobacco dust and sulfur) is not appreciably improved by the addi- 
tion of any of the more common conditioning agents used in combati ' 
aphids. Conditioning agents tested were: One or 2 percent of peanut oil, 
4 percent of soybean flour, and 1 percent each of peanut butter, cottonseed 
oil, pine oil, oleic acid, sulfonated caster oil, sodium oleyl sulfate, and 
an alkyl ate d naph thai ene- s ul £ ona te . 
Haude ( 144 ) in 1939 recommended oube or derris dust (0. 75-percent 
rotenone) pli:s 0.5- to 1-percent of a wetter, applied at 30 to 50 ] 
per acre with a canvas trailer when the .Xante are dry, 
Rhopalos inhum subterraneum Mason 
Rhopal o s i phum sp, [probably R, s ubterrane um, ] 
(See reports of tests made by the South Caroline- Agricultural 
Experiment Station (249) and Rainwater (228) under Anuraphis maidi- rad ic i s 
Forbes, pp . H-5.) 
Toxoptera aurantij (Fonsc,), the black citrus aphid 
Tests ware made by Worsloy (323) in 1934 with Derris, Tephrosia , 
and Lonch o c arpus a citrus ap : ids at the East African Agricultural 
Research Station. Dried ground material was shaken in absolute alc< 
(9 cc, alcohol for each gm. of material) for 24 hours, filtered, and 
brought uo to 10 cc. volume per gn. of material by washing the 
with alcohol. This is called a 10-percent extract of the plant material. 
The method of assessing the effect • spray: bo take 10 aphids 
for each trial ami to examine them 24 hours after spraying. One-half 
percent of soap or 1 percent of saponin was added as a spreader 'he 
spray was applied for \ seconds from a distance oP 18 inches. Tests were 
mads with the root of Derris elliptica ; the flowers, seeds*, leav , .ds, 
stems, and roots of Tephrosia vogeliij the leaves, seeds, nd roots of 
—' toxic ari a; the leave:-, seeds", and pods ol T. nyikensis ; th 
seeds, and roots of T, C andida ; th leaves ai i seeds of T, tocfciflora ; 
and the leaves and roots of 2 sp< .>f Lone ho carpus " nd B, 
Extracts of Dorr is j] 1 ipt lea roots and e of t, vogelii bhe 
most toxic, killing 100 percent of the aphids. 
