- 99 - 
0.5 pTcont of rotrnonr pnd. thr drrri<= sprpy contain^.ng 0.025 prrc<~nt of 
rotcnono in vatrr, vrith or vrithout a sprradrr, wctp not rffrctive against 
th" Inrva-. Prpliminp.ry field nxperimontF: in Louipiana. indicptr-d tha,t 
rotf'nonC' compounds may 'b'- off "cti-"'-^ against vog-tabl'- vr-^pvii lar"-ap if appli'^d 
at frfouont intervals to plants infost' d with small la.rv»r, .Ag-'^inr:t adult 
•^rgetatlp- w-'pvils, darris dust containing 1 Torrcf^nt of rot"nonr killed 6,66 
pr-rcnt pnc. derria dupt containing 2 pr-rcnt of rotanonr killed 2^,ii- percr-nt. 
China cl?y vrap used as the diluent. All mortalities vr-r^ ots'-^rv-d ^ days 
after trentment. 
The Louisiana Agricultural Sxp^^rinont Station ( 26^ ) in IP3S called 
attention to the report of Harri??on ( igO ) , who foun:^ that a dust containing 
1 pTcent of rotenone^ vrith eithrr tohacco dust or sulfur ac a carrier, is 
•^cry satisfactory for controlling th' vegetalDle vrervii on turni"Ds, mustard, 
swips ch^rd, ^nd oth^r leafy vegntablrs. G-ood control vras ohtainrd "by dust- 
ing one-' "■•"■' ry 2 weeks during th'^' gro^'dng season. 
Par, to moras Irucolom^' (Boh.), tho '-'hite-fringrd "b etl^. 
Englisi and G-r.^ha-, ( II5 ) in 193? r~port-^-d that experiments vrith a. 
number of ins cticideg for sterilizing soil contain'ng larvae of the white 
fring-d hr-etle, ( Uavpactus ) F^ntonorus lencoloma (loh.), gave negati^p results 
a.t concentrations which were s=^f'" for nur^^ry plants. Potassiim cyanide in 
aquoeu? solution vras the only chemical that showed definite toxicity to the 
larvee in the soil. This che-iical offers promis~ f^-^r sterilizing soil that 
does not contain plants. Results with hot vrat r, st'-'am, and electrical heat- 
ing devices were negative, Earth balls (12 inches in diameter) containing 
Inrvof vrere submerged for I5 m"=nutes in various insecticides -^nd wern examined 
Ug hourrs lat-r with the following results: 
In. 
F-ecticiee 
Dilution 
rail 
lerccnt 
Derris ex' 
bract (pine 
oil) 
20 cc. p'-^r gallon of 
1:500 "4/ IF U3g 
21 
Derris-1 
8 cc, p.'-r gallon of 
1 J 500" \/ li" i^3S 
17 
Cub' root 
19 gra. ner gallon of 
1:500 \VlH U^8 
10 
roliafu-ic 
20 cc. T) r gr^llon of 
1:500 4'-IiT-'-^3? 
13 
Florida v. 
olck (g^vc 
the 
highest 
kill) 
1:8 
90 
ITurs -r ' ■-'( 
Dick 
1:50 + cub- root 1:200 

^/' This i^ a sulfnt-d nlcohol. 
Phi 1 or) e don plagi-^ tus (Schall'r) (^yn, , ( Cn'-orhinus ) Curculio g^-min^t^xs F.) 
Resistant to derri^, — Anonymous (2) in l'^'^7, 
Phyllcbius oblongus (L . ) , a graft we.^vil 
P. pyri (L.), -i grpft '^.r^evil 
Sep Krarns end Umpl.-by (2-- 1) un^.-^r Er^chyrhinu^ ^ing^il-'ri"- (L,), -oagss 
9.U and 39. ' 
