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The Bureau of Sntonology and Plant QvLJirantine of tha Unit-^d States 
DepartTient of Agriculture (_22J) ^^ ^93^ reportrd result? of various tests 
vitb rotencne,. derris, and cute,. Fiold experiments with insecticides in 
Ohio and Virginia, on "beans grown for the green-bean market or for canning, 
havo dera-nstratrd that . the Mexic&n "bean he-tle can "be controlled at a mini- 
muni cost by applying sprays or dusts cont.a.ining rotenone derived from derris " 
or cube without danger of incurring harmful residues on the mark'^^t product. 
Laboratory siudics disclosed that the active ingredients of derris were ad- 
sorbed and tran-slocatod in treated plants in. such a manner as to prevent 
extensive feeding of bean beetle larvae on foliag- that developed on the 
plant-s after- the insecticides had "bepn applied. This residual effect of 
rotenoiB-containing. insecticides ha.d been obs^'rvcd previously under field 
conditions, 
Wallis ( Upg) of Srand Junction, Colo., in 1936 rcportrd that the 
results of field-control exp^'riments performed against Epilachna varivestis 
in 193^ 0^ beans grov/n under irrigation- revealed that a derri.s-spray sus- 
pension containing 0,015 percent of rotenone is- as effective as a derris 
spray containing 0.02 pr-rccnt of rotenone. Sprays containing 3 pou^ids of 
cryolite to 50 gallons of water, or derris contai'iing 0.015 percent of rote- 
none, or cube sprays containing 0.02 percent of rotenone, were more efficient 
than a spr8.y containing 1 pound of zinc ers^nitc to 50 gallons of water. The 
latter sDray is most commonly used by growers of beans in the Grand Junction 
district", 
Eotenone .sprays or dusts after pods have formed were recomnended by 
Bourne and Boyd (^) in 1937. ; ■ 
Brannon (^) in 1937 summarized the results of ins«5cticide tests 
performed against the Mexican bean beetle in 193^ o^^ ForcLhook lima beans 
tt the ITorfolk, Va. , laboratory. The best control was obtained v/ith dust 
mixtures of dorris-sulfur and cube-sulfur, each, contain-'ng 0,5 percent of 
roteno:e. Derris-wettable-sulfur p,nd cube-wet table-sulfur sprays (each 
containing 0.01 percent of rotenone) also gave good control of the insect. 
The percentage of control vdth the dust mixtures V^as slightly superior to 
that obtained with the sprays. 
Brannon (U2) in 1937 reported that recent experi;nents at the Norfolk 
laboratory, designed to determine the relative effectiveness of derrip, 
derris-sulfur , cube, cube-sulfur, pyre thrum- sulfur, and sulfur alone, applied 
as dus-ts or as sprays for the control of the Mexican bean beetle in associ- 
ation with the greon clover worm ( Plathyoena scabra (F.)) infesting snap 
beans, showed tha.t in instances where this ppst occurs in association vrith a 
Mexican bean be-.tle infestation, sulfur should be used as a diluent for derris. 
or cube for the combined control of the two insects. The derris and cube 
dust mixtures contained 0.5 percent of rotenone, the derris and cube sprays 
contained 0.015 percent of rotenone, and the pyrethrum-sulfur dust mixture 
contained 0,1 percent of total pyrethrins. Wettable sulfur was used as a 
spray at the rate of 2 pounds to 50 gallons of wat'^T. 
The Colorado Agricultural Experiment Station (SU) in 1937 report f^d 
that a dust cottaining 0.75 pcrcert of rotenone used on the Mexican bean 
beetle failed to give satisfactory -control. A spray pf U pounds of derris 
containing U percent of rotenone to 100 gallons of water gavr. control eaual 
to th»t effected by zinc arsenite and magnesium arsenate or phenothiazine, 
h pounds to 100 gallons of wat^r, und^r heavy infestation. 
