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In 1930 the Unitod States Department of Agriculture (^SO) called 
attention to its research on rotenone, whinh was b^ing tested against 
the Mexican "bean beetle and other destructive insects with r^ronising results. 
Darley (96 ) in I931 sprayed adult Mexican "bean "beetles confined in 
small wire-screen cages with an aoueous suspension of rotenone made by add- 
ing a 2-percpnt solution in acetone to water. Rotenone at 1:50,000 was 
ineffective. Rotenone suspended in wat--^r 1:200 sprayed on lea""'es and fed 
to the larvae as a sandwich killed all. At 1:5,000 all adults on a sprayed 
plant were killed and at 1:10,000, 90 percent were killed, — Davidson, re- 
ported by Campbell ( 66 ) in 1932. Campbell also reviewed work by Howard, • 
who reported the failure of a dust -containing 0.15 percent of rotenone to 
protect beans from Mexican bean beetle attack, Tvro applications of 20 to 
25 pounds per acre gave some temporary protection, bii.t at the close ^;f the 
experiment, 25 days after the second treatment, the folia^pe-had be^^n de- 
stroyed, whereas the magnesium arsenate plots remained green. Howard also 
used concentrated ftaueous suspensions of rotenone in cage" tests against the 
Mexican bean beetle, with disaTopointing results, 
Douglass (105) in 1933 report'-'^d the*results of 'tests of insecticides 
against the Mexican bean beetle in New Mexico , Derris dust a.nd Cubor dust 
killed more beetles than did arsenicpls and barium fluosilicatp, Derris 
dust containing 1 percent of rotenonS was m'-^re effective than Cubor xust 
against overwintered beetles, larvae^ and newly developc;'. bo' ties. 
Howard, Brannon, and Mason ( 193 ) in 1933 reported that in I93I they 
had found a commercial dust containing 0,15 percent of rotenone to be in- 
effective; in 1932 a- commercial dust containing 0.275 P^^rcent of rotenone 
gave fair results. A commercial extract of derris r^^^^t, containing 5 ^. 
of rotenone per 100 cubic centimeters, with other extractives, gp^p satis- 
factory control at Norfolk, Va, , in light to mediiim infestations, vrhcn used 
at dilutions of 1: 250, l: 500, l: 200, and l: 1,000. In medium t- heavy 
infestations, in Ohio in 1932,'at 1: 250 and l: 400, it gave results equal 
to or better than magnesi'im arsenate at 2 pounds to 50 gallons and cryolite 
at 2 pounds to 50 gallons 'of water, and better than a well-knovm pyre thrum 
extract at 1? U,00. Derris extract appears to be superi'^^r to r,.yrethrum ex- 
tract and equal to a comTb'iriation of the tiro, and far superior to pure rot- 
enone. 
The Suffolk County, IT. Y. , Farm Bureau ( 361 ) in 19-^3 called attention 
to: the use of rotenone and jjyrethrum insecticides for controlling the Kox- 
ican bean beetle on both string and lima beans. In spraying lima beans tho 
pyrethrum- or rotenone-spray extracts may be added to the bordeaux mixture. 
In this way the bean beetles, lice, and mildevr or pod mold may be controlled 
with '^ne spray. A-oparently the bordeaux decreases the killing properties of 
the rotenone or pyrethnm a little, but the sprays should gi^e .pod control 
if applied as soon as mixed, Borvdcaux is n'^t needed on string benns. 
Should beans require spraying -against the Mexican bean beetle after 
the pods have set, pyrethrum or derris oxtract«5 must be used. — United States 
Department of Agriculture , Bujreau of Entoraolog,y ( 3io6 ) in 19!''3. 
