- 53 - 
Boyce and Prendergast (19_) in 1938 v.rotc that the oil rotcnone 
mixtures are relatively expensive when considered for the control of the 
red spider alonej however, when considered for the combined control of 
aphids, the red spider, and "off-hatch" black scale during the spring, 
they arc very practical. 
The California Fruit Growers' Exchange, Bureau of Pest Control 
(38, 39, 40), in 1938 recommended oil-rotenone combinations for combating 
the citrus aphid, A 'suitable spray is made from 0,5 to 0,75 gallon of 
light medium oil, 1 to 4 pounds (depending on brand), of rotcnone powder, 
and water, to make 100 gallons. This formula may best be used where the 
red spider and black scale are present along with the aphids. One of the 
rotenone oil sprays such as Botano-R, Tox-X, or Rotox with 0,5 percent 
light medium oil will control both aphids and red spiders on citrus. The 
rotenone-oil combinations used effectively against the red spider on 
oranges in the coastal Valencia area also cares for any aphids present, 
Aphids en corn 
Miller (202) in 1935 tried aphids on corn as test insects in deter- 
mining the insec~£Tcidal value of various species of Derr is, but they proved 
too susceptible and difficult to handle; 100-percent mortality was obtained 
each time, not only with the insecticide but also with the control fluid. 
Aphids on currant 
The currant aphid was net controlled by a dust of equal parts of 
derris and hydrated lime. — Kelsall et al. ( 170) in 1926, 
Aphids on dwarf spruce 
The 1 Wageningen Plant enziektenkundigen Dienst ( 29 3 ) in 1933 reported 
that a suspension of rotcnone in water (l: 5,000 ) made by adding an acetone 
solution of rotenone to water and also derris pov/der in water 1:50 (equiva- 
lent to rotenone at 1:2,500) plus 1 percent of soap gave satisfactory con- 
trol of' leaf aphids on dwarf spruce in Holland, 
Aphids on eggplant 
The Japan Seed and Plant Company, Ltd,, of Tokyo, Japan, in 
advertising Derri-Homi (a proprietary derris product), stated [n.d.] 
that the Agricultural Experiment Station of Saitama Prefecture, Japan, 
found that this product at about 1:320 killed 100 percent of aphids on 
eggplant. 
Aphids on flowers and fruit 
The Handelsmuseum of the Koloniaal Instituut of Amsterdam (8) in 
1930 reported derris to be an exceptional material for contrcl of aphids 
on flowers and fruit in the greenhouse. 
Fryer ( 108 ) in 1S26 referred to the use of Derrisol in England for 
the control of aphids on fruit. 
