~ 6g - 
Ground derris r'-"-t vith' a carri ;r used a?' a dust ;~-'3."^.'^ very "r'-.nis- 
irrg results. The general C'.nclusi^n from a lar.^r numter of arplications 
WPS that a dust should contain from 0.5 to 0.75 percent cf rotennne (10 
pounds of 5 percent derris to ^0 pounds of. carrier or 15 pounds of 5 per- 
cent derris to 85 pounds of carrier). Of six carriers, ?.nd con"l:in?tions 
of carriers, ccnpriiiing talc, tobacco dusts, infusorifil earth, ground narc 
(extracted pyrethrum flovrers) . inert cla;^, and hydrated lime, ta.lc is generrl 
proved to "be the test. Ycrv good control of the 'bean "beetle was '^'btained 
when 20 to 25 pounds was used to the acre. Eydrated li-ne in sor-e instance? 
appeared to reduce toxicity and should not "be recoTimended, 
The same authors ( 19^ ) in 1935 issued instnacticns for tlie eontr-^l 
of the Mexican "bean "beetle in the Eastf^rn States, Derris was one of the 
insecticides recommended. To prepare a derris spray use U or 5 P'^unds of 
finely ground derris (rotenone content ^ percent) to 100 gallons of wat-T, 
These sprays will ha.ve a pot-^nor.e content of approxinately 0,02 and 0,025 
percent, respectively. No spreader or sticker is renuirod. Directions are 
given for preparing dusts containing 0,5 or 0.75 percent rotenore from derris 
of U percent rotenon^ content and talc. Other diluents which nay oe used 
are infusorial earth, kaolin (china clay), dusting gypsum, wheat flour, and 
totacco dust, Fine dusting sulfur may "be mixed with the infusorial earth or > 
clay to the extent of 25 pounds of the sulfur ■su"bstituted for a like fimoiuit 
of the earth or clay. Some prepared dusts may "be thoroughly mixed "byplacing 
the ingredients in a drum or "barrel, not over two-thirds full, and rolling 
and tilting for 5 minutes. Commercial dusts may "be o'btained alrcp.dy mixed, 
Dusta are usually applied at dosages of 20 to 25 pounds per acre on snap and 
"bush "beans, "but vdth careful application thr dosage may sometimes "bo reduced, 
Howard and Da""'idpon ( IQJ ) l^i 1935 tested the devil's -shoestrings 
root against the Mexican "bean "beetle in Ohio, They reported that. "both a 
dusting mixture of this root containing a- proximately 0t6 percent of rot en- 
one and a spray with a content of 0.01 percent of rotennne gave satisfactory 
control on small plots of heavily infested "beans in the field, 
Howard, Mason and Davidson ( 200 ) in 1935 reported that 3 po'^andfl of 
derris containing U.U percent of rotenone to 100 gallons of water was 
effective against Mexican "bean "beetle, Derris spray v^as "better than derris 
dust "but 20 to 25 pounds per acre of the dust (0.5 to 0,75 pf'-rcent of roten- 
one) was fairly effective, 
Huckett (20U) in Septemher 1935 recommended derris as a spray or ^ 
dust for the control of the Mexican tean "beetle. As a spray, use U pounds 
of derris (U.5 to 5 percent rotencno content and 15 to 18 percent total 
extractives) and U poimds of Kayso or skia milk powder to 100 gallons of 
water. A suita"ble dust may "be made "by mixing 12 pounds of derris of a'ove 
grade with 88 pounds of talc, clay, or r'ir-floate.d .lyT^sum, 
Huckett and Hervey (207, 388) in 1^35 roport'^d that derris and cube 
sprays and dugts have shown promising result.e for the control of the Mexican 
"bepn "beetle on lima and snaji "beans on L-ng Island, 
