- 2h - 
1935 potted pea slants were sprayed with derris and later infested with 
aphlds. -The spray 'consisted of 'ground derr-'is; '-root i^.2 percent rotenone 
and 13 percent total .extractives) used at \a 'dilution to .'obtain O.0115 
percent of rotenone '{3 pounds per -i'OO ga'llons'Adf ":water) and one of -two 
spreaders and wetting : - agents j either 'a 7 sulfated'butylated diphenol 
[Aresket -2^0] at a dilution'-of l:600 ; of-^ tt®"^percent'- aqueous solution, 
or a sodium oleyl sulfate, special, at the dilution of 1:1,000. Small, 
uninfested potted pea plants were sprayed thoroughly, allowed to dry for 
2U hours, then lightly infested with third and fourth 'pea aphid instars, 
and. arpperly caged, there being an average of four plants to the pot. ' 
Bronson concluded that derris spray, containing either of the two spreaders 
and wetting agents used in these .experiments, protects potted pea r plants 
artificially infested with the pea aphid for a period of 7 days against 
any "building up of the original infestation. 
. . In' 193b Bronson described a hall mill for mixing cube or derris 
powder' with a diluent and with an activator or conditioner. These dusts 
have proved to be toxic against the pea aphid and it is believed that - 
thorough mixing greatly increased their effectiveness. In 1937, he .des- 
cribed an irrir 1 oyed apparatus for mixing derris or cube powder .with a 
diluent and a conditioner. One hundred pounds of dust containing 1 percent 
of rotenone for use against the pea aphid is made ''oy mixing 25 pounds of 
derris. or cube root powder (^ percent rotenone), 72 pounds of. talc or 
other suitable diluent, 1 pound of conditioner (wetter and spreading 
agent), and 2 pounds of water. Satisfactory conditioners are sodium 
oleyl sulfate and an alkylphenylbenzenesulfonic acid. Tests were made 
in a greenhouse at Madison, Wis., with different spreading, wetting, and 
sticking agents used with derris sprays against the pea aphid. A commer- 
cially prepared product containing a sodium oleyl alcohol sulfate was 
the most effective agent used with derris, and resins or other adhesive 
agents were not effective in protecting the active ingredients of derris 
from loss either through decomposition or from being washed with a water 
spray.' The pea plants vere first sprayed with a derris solution contain- 
ing one of the spreading, wetting, or sticking agents. Some of these- 
treated plants were hand-infested ?}\ hours after they had been sprayed: 
others were washed twice with water and inf-ested 5 days after being 
sprayed. The results showed some residual effect of -derris in all the- 
tests in which plants were infested with the pea aphid 2U hours after 
being sprayed, but probably no residual effect of derris was apparent in 
the' plant? washed twice after being sprayed,, and then infested with the 
pea aphid. 
In July I93S Bronson issued revised directions for mixing rotenone 
dusts (see 26) -in a cement mixer. The derris or cube root powder should 
be of such p. degree' of fineness" that not less than 90 percent of it will 
pass through' a 200-me-sh sieve and all the material (100 percent) should 
pass through an SO-mesh sieve. The talc or other diluent used should 
be of such a' degree., of fineness that .all the material will pass through 
a 300-mesh sieve." . Tn most of '.'the experiments and field tests against 
the pea aphid thus far, a sodium oleyl sulfate (Avirol, IIT-U3S ) was used 
and proved satisfactory.. Other proprietary conditioners also proved 
satisfactory. 
Dudley, Br'p'n'son,' and Carroll (87, S3, g£) in 1936 reported the 
