Ii 1936 ChamDerlin (70) al-^o TP-norte:-. te<=tR na-^^e nt Q.ui?icy in IQ"^^ 
in which he fovnd thfit clerri? anc. c.^of ^ diluted Vith a fin--, nearly neutral, 
denicotiniz'-'d t'->'bacco dust t^ a rritr.none C'-^nt^nt of 0.05 P'^^cRnt wprr- (^qnall;; 
effective (S5 I'-ercnnt mr^rtalitr) whan dust-=d on the to"b^ccn fle'a "b'^atlo und-] 
CP gf^ c '1 n '"'.i t i n p . 
Roar'c ( 327 ) in 1^3^'^, i^- '^ rr-^i-^-w of the camT^arative inspcticidal 
r?lnoF '-^f darri? and c^ih?, ref^-Tred to thi? finding "by Cha'n'berliii. 
Howe (201) in I936 rer.art^d te^ts ^a ' e at Clar-pvill'-^, Tonn. , a-rr-in^t 
thr toh^ccr fl'=a bertle, vhich indic^tfd th=-' t ^ c^^hr—root-dupt nixtura hav- 
ing ^ rotano^^.f^ c^ntf-nt of approri-aately 1,5 Tf-rcfnt va? th^ noft toxic ^f 
the nptrrial'' t-^tad -laainpt the flaa "b-^ftlo ^n d-^rk-fired tohacco, ''-.-wt 
th?t a r:inilar du^t m^'xtur^ containin^ 2 percent of roten'^n-- wnc; nost affic- 
ient in the te'^tp ^-dth Surley toh^cco. In ^^'^n r^^l, howpT-,-r, it aaoe^^rpd 
that tha dust raixturr containin._- 1.5 ""orcant of rotenonp Mr.<^ so nc^Tl;.'- 
equal to tha nixtura c^nt^ining 2 percent of rotonon^ tho t the foj-mer di- 
lution ia ar-f"rphl.- oacoiica of it*^ lov;rr cost. The cu"ba-du=;t fixture 
prorad none affr^ctiva than a nixture '^f 50 percent of cryolite and 50 per- 
cent of kaolin, or a. nixture c^maoped of " aarcent --^f ■nori?^ gre-n, '•'•2 •oercen^ 
of lead arpenat", Dnc. 50 '^■^arcrnt '^f kaolin. E-epults indicated ■''■ery little 
difference in tha relrtiv^ toxicity to flea he'-tlep ^n toh^cc"' -i-^lant oed?! 
"between the two la^t^.-nenti -^nad du'^t raixtu-re?:. 
Ex-eriaent? in Plorida and TenneR-^ea disci pod that a darris or cuDf=- 
dust mixture containing 1 •''■'^rc~nt of rotenone was effect i""''= in cntrolling 
tha tobacco fler, tfetlr- in the Dlrint bed, af' well a"=: ^n newly c?r-t nl^nts ^nr. 
on the grovinc: crorj. T^'^t?. with different diluf^-nt?: for th- derris or cuho- 
rcot powder indic't^d that st'^'rilizi^d tolacc^ du^t wnc: th--- -lofit =:uit?':la far 
this ourpopa and did not l''OV<= unr.ightly de-:.-iositf3 on th-- harve^t.-^d plant?. 
The United St^te?. Deaart'-'ient of A;:riciilturp', B'j.re-iu ^f Entomology and Plant 
Quarantine- (^.9-=)) in 1Q;^6. 
Tie South Carolina Agricultural Sx^ariaont Station ( 3^8) in I936 
ra-;iort-d th^t at thr Pee Dee Exioeri-ient Station tests against tohacco flea 
"beetle"? war.- '■aade with d^^r'is dust (l perc-">nt r.f r'-trnone) •-■nd cube dusts 
(0.5 ^■'^-^■' 1.0 ni^rcent of rot^^n-^-n'-" ) . Th- difference in tha norcent^ge of 
r'"-dT.ction of li-i'in^:: I'-etlos with tho rotenone ■-•nd the n^^nrotenone dusts at 
the and r^f 72 h'^ur'^' w^s not sufficiently gr^at to vra.rrant the sol^^-ction of 
a,ny of the nateriols as outstanding. Kow'-VFr, the grentest ■Dcrco--'.tai':;es of 
dead "beetles were o'Ltained fr-^"-'. the p--.lic^' ti-n of dust iiixtures derris e^r.d. 
cube containing 1 -nprcont of rotej^^n-. There vros no significant difference 
between thf=se twn insect ici '.es , elth'^ugii thpre wpt a tendenc^' for the cube 
of l--oorcent-roten"ne c^nt^^nt to lost-' its ef f ;~-cti^'eness f-^st'^r than the dorr' 
In fiold tastq pg.q.inst the tobacco fle^, bei~tle on s'ladf^-^-rown tobacco 
in Flr^rid^, i\ S. Cha'^.berlin (72) r.-i-ort'-d in 19"^7 that cubf- dusts contein- 
^-'■''.g 1 ^r 1,5 V'r-Tcnt of rot<"'none vr^-re more i=ffecti^"p than a cube dust con- 
taining 0.5 percent of roten'^nf. Lat*^r (Tj) he re^'ortod a dust containing 
1 percent of roten'^ne and sterilizr.d tobocco as r? diln.ent o,p-nlied at the 
rate of H to £ nounds r'^r acre to bo . ffective in controlling tha tobaoco 
flea beetle ^'n shade- crowr. t^bncco. A-*:'plic^' tions ma.de once a, wer^k should 
ordi'-'-iril;' nrotect the crop su-f icier.tly. 
