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Dorris dust (0,5 percent of roten^-r.e) ar.l spray (U po^onds of powder 
of U percent roten'^ne content) arn eff ^cti-^'c. — Alabana Polytechnic Institute 
(g) in 19^5. 
BotD (^)of the Virginia Agricultural Exporio^nt Station reported 
in 1935 that rcte-ono dust at certain ptrr^-ngthe vas effccti^'e in destroying 
Mexican "bean beetles. 
In 1935 Brannon ("^U) re^^ort-d that sprays were superior to dusts 
in control of the Mexican tran "beetle in Virginia,. A spray composed of 
3 pounds of synthetic cryolite in 50 gallons of water and a derris-r^ot- 
powder spray .containing 0.025 percent "^f rotenone gave perfect folia^ee 
protection pgainst tlie uean "beetle and increased the yields 3^ and 33»5 
'■percent,' respectively, s,s compared with similarly situated untreated plots, 
A dust .'fixture composed of synthetic cryolite and talc (60-U0) and a derris- 
talc 'dust ccntaii-.ing 0.22 percent of roten^ne .gave fairly satisfactory re- 
sults p'nd increased the yields 32,9 an.-". 23.8 percent, respectively, as com- 
pared with mitreated plots. These materials were applied with a traction 
dTister nnd a traction sprayer, respectively^ on l/2-acre replicated plots. 
Cory ( 388 ) in 1935 stated thpt Marcovitch, of Tennessee, reported in 
Decem"ber Vijh that Cutor, 1 pound to 50 gallons '^f wat^^r, gave the ""iest 
control of the Mexican lean "beetle. Turner, of Connecticut, reported that 
Cu"fcor spray and Oul-)or and Ku"batox dusts gave gor,d control of this insect. 
A dust containing O.U percent ^f rotenone applied once on first-generation 
and 3 times on socond-i--renorotion larvae ga^'e excellent control, Sherman, of 
South Carolina, reported that Ku"batox killed 52.5 percent of the old adults, 
55»7 percent of the new adiilts, and 6U,6 percent of the larvae. 
N, F. Howard in a tj-pev/ritten rerort to the Division of Truck Gr^p 
and' Garden Insect Investigations in 1935 reported the results "-f tests with 
cuLe against 'the Mexican "bean "beetle at Columtus, Ohio. Cu"be (rotenone, 
7.7 percent) at 3 pounds per 100 gs.llons , applied at the rate of IIS gallons 
per acre, and derris containing U.U percent of rotenone ga,ve 92 percent 
"better control than the check. The addition of 1 pound of Kayso or 1 pound 
of soap to the cule spray gave a"bout the same result. Both derris and cu"be 
8prR.ys gave "betto-r control than cither magnesium arsenate or synthetic cry- 
olite. A cu"be powder diluted with talc to a rotenone content of 0,77 per- 
cent and applied as a dust rt the rate of 21 pounds per acre gave as good 
results as sprays of magnesium arsenate or cryolite. Derris and cu"be dusts 
did not f-ive s-- satisfactory controls as did th" s^^rays, 
Howard, Brannon, and Mason ( 19U ) in 1935 reported that finely c:round 
derris r^ot in water aprearrd to "be '■•ne of the cest insecticides ever tested 
for the control of the Mexican ""oean Irootle. Vhen used alone it gave "better 
results than when used with pow.'.ored soap, lime-casein, or "be- ntonite-siilfur. 
Derris stays in suspension and sticks well, even to ca"L'":ago leaves, and lias 
a"bout as lasting effect as any material yet treated. "Vrr;' go.od control was 
o"btained at dose.^cs of 3>'"*", ^•^'■'^'' 5 pounds of derris, of L|.,U percent roten-^nR 
content, in 100 gallons of water. The wat.-r suspensions of derris powder 
were superior to the extracts 'f derris r pyret';.rum, or a combination of 
the two. The increase in residual cff-ct of th--^ ground root over thjs.t of 
the extract was marked. L"''^oratory tests indicated that derris dusts and 
spr-'^ys are toric to the eggs of the bean "ueetle. 
