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scalc control, straight oil spray will also control the red spider • llihero 
rotcnonc is used with a light dosage of oil, the control wiliL. he only temporary 
unless aided greatly by weather unfavorable tc the /spider. 
In April 1940 the Exchange (36) reported or. control of red spiders 
oranges. In coastal areas, if aphid's beccno a pest altn ■ with the red spider, 
one of the rotenone-oil sprays rath 0.5 percent of light-nediun oil should be 
the preferred treatment to handle both pests. The formula given: Light-medium 
oil l/2 to 3/4 gallon, rotcnone powder 3/4 pound to 3 pounds (depending on the 
brand), and water to make 100 gallons. 
The Exchange (37) in January 1941 reported on the control of red spiders 
or citrus fruits. If scales are also present in immediate coastal areas, 
light-medium oil or cil-rotenonc night be used. In March 1941 the Exchange 
(3c) recommended one of the DK dusts as the preferred treatment at that time of 
year. If rain falls soonerj n than 3 or 4 days after tho application, its effec- 
tiveness is greatly reduced./ Valencia areas along the ccast, where aphids may 
be a post along rath red spiders, one cf the rotenone-oil sprays at 0.5 tc 0.75 
percent of light-medium oil ' is the preferred treatment to control both insects. 
T.hcrc oil is used fcr scales on lemons, it will also control tho red spider. 
Tetranychus althaea® v. Hanst." . 
De3ussy ct al. (1C) in 1936 reported that (Epi tetranychus ) Tetranychus 
althaeae was not Controlled by derris dust and was imperfectly controlled by 
dcrris spray, which was more effective than pure rotencne (both on a basis of 
rotcnonc 1:3,000). In each spray material 0.05 percent of lethalato was added 
as a spreader. 
Tetranychus mcd anieli T.cG. 
The Michigan Agricultural Experiment Station (103) in 193]. reported that 
Derrisol at 1:800 plus 2 pounds cf Ivory soap per 100 gallons killed active 
raspberry mites thai; were fairly hit by the spray; and in 1932 this station ( 104 ) 
reported that many sprays were tried fcr the control of this species, among 
then glue, oils, nicotine, pyrethrum, derris, soap, and as many combinations as 
time permit-ted. It was finally demonstrated that summer oils used at the rate 
of 1 percent, cither alone or in combination with bordeaux, controlled this pest. 
Hutson (77) in 1933 reported that in tests of single applications of 
insecticides, Derrisol 1:800 plus 2 pounds of Ivory soap in 100 gallons was 
sprayed on raspberries with an orchard sprayer developing 250 pounds pressure. 
Alter this treatment 247 live mites of this species wore found per 100 loaves, 
as compared with 822 on the check. The host control, 114 live mites per 100 
leaves, was obtained with glue at the rate of 15 pounds in 100 gallons cf water. 
Tetranychus pacif icus T.'cG. , the Pacific mite 
The Washington State College Extension Service ( 1 55 ) in 1940 stated that 
rotcnone material (powdered dcrris, cube, and Timbo) containing not less 
