LEPTOPHOS AND OTHER INSECTICIDES FOR CONTROL OF INSECTS ON FLUE-CURED TOBACCO’
By W. J. METRIC, JR., and F. D. SMITH’ Department of Entomology, North Carolina State University, Raleigh, North Carolina, USA
illxt3c.i icidr methorny1 SP, and ;l nontreated check repli- Control of the tobacco budworm, Heliothis virescens (F.), catt,ti :: times in a randomized block design. Plots were 2 tobacco hornworm, Manduca sexta (I-.), and tobacco flea beetle, Tobacco Science, 1974, 18-31, p. 87-88, ISSN.0082-4523.pdf Epitrix hirtipennis (Melsheimer) on flue-cured tobacco with various roan x 621,5 ft, and there were 2 nontreated buffer rows rates of leptophos WP, encapsulated methyl parathion EC, MC- btqwt~t~n plots. Blocks were separated by 20-ft vacant 4044 EC(O,O-dimethyl-O-(1, 2. 5.thiadiazol-2.yi) phosphate), and methomyl L was compared with that of % lb/acre of methomyl all~~~-s.Plant. height rnnped consir!erably from one ex- SP. One, %I, and l/z lb of leptophos were superior to methomyl Iwl~lmt~tll to another, but no experiments \vere conducted SP against flea bettles. One-half lb of methomyl L was slightly superior to methomyl SP against budworms, hornworms, and flea 011small 01’ ni:iturr plants. beetles, but the difference was significant only with respect to To assuw hravv, uniform larval populations in each budworms. Treatments as effective as methomyl SP against specific ])lot. OIIV budworm larva \vas placed on the bud of each . insects were: 1 lb of leptophos ard methyl parathion against budworms, 1 and 3/h lb of methyl parathion against hornworms of ?,(I rlotlitlfested plants ant1 2 hornworm larvae Lvere and flea beetles, and 1, %I, and Vz lb of leptophos against horn- plxetl on ytrung leaves of each of IO noninfestcd plants. worms. Against budworms. llb of MC 4044 was slightly superior to m?thomyl SP, M lb of MC-4044 was similar to methomyl SP. Thr I~utlworm larvae \vere l-2 days old, arid the horn- and % lb of MC-4044 was slightly inferior to methomyl SP. \~orrn I;wv;I(~ \vew ilr stages 2-4. These inwcts were These rates of MC-4044 were less effective than methomyl SP obtai tletl from laboratory colonies reared on artificial against hornworms and virtually ineffective against flea beetles. meclia at1~1renewed each year w?th local stock. IH~~KY~UQPI/~asc,.s--Tol);~~co, i nsrcticidal control of to- bacco insects on : insect. (tobacc~oljudworm, tobacco horn- \vor’ni. tobacco flc:l beetle 1. inser+icidal control on tobac- co; insecticides (lvptophos, methom~l, methyl parathion, MC-4044) against. tobacco insects (tobacc,o budworm. Thr number of live lawae on the artificially infested tobacco hornworm, tobacco f7r.i beetle) ; Hdiothis vi- lkii~t s \\i,s rtwrded :3, 6, and 10 day* after trratment. J’(‘.scc’JL~; L~londr4rr/ SP.r’tcf; Epitri.r’ hiCtipPJLJ/i:i. I.arv:w l’rorn eggs deposited OJJ these plants during the cSslwrinwtltal pericd were included in the records. The INTRODUCTION sum of Iwrtions of leaves consumed by budworms and The performanw of JICLW v.uI)t,rimt*Jlt;ll in:wclicitl<,s ap- horll\\ c)l.rns \V;IS recorded on thr 10th and 12th day after plied as sprags against the tobacco bud\vorm. Hvlirlfhis t rral rnc>llt, respectively. Leaf consumption was esti- ?!iwscc~ns CF.), tobacco hornworm :I~~rtnd?cm .w.rtm I I,.). m;rttbcl 1 isu:~ll~ to the near& l/l0 of a leaf. In some and tobacco flea beetle. Epit) ix hirtipmJli.s ( ;\Ithlshe- test\. ihr nrlmber of adult. flea beetles 011 10 plants/plot imer), on flue-cured tobacco w;ts wported recently (2 ). \VilS I’t’V~lrtlVd ii, 6, iiJld 10 days after treatment. The most promising insectici~lw tested included Su- 111wct irlfestation ant1 leaf-consumption data \vere pracide* (S-( (2-m~thox?,-:i-oxo-:‘:‘-l,~~,4-thiadiazolin- transformed to the square root of X + lli as suggested 1,~ 4-~71) methyl) O,O-dimethyl I)h,~sphorndithioate), ace- I,eClrrg tat ;I]. I I). The twnsf’ormed data were subjected phate (OrtheneR’), Zwt,ran* (4-dimethvlamino-3. 5x.yl:l to iIJl;ll? SjS Of variance, and Duncan’s multiple range methylcarhamate 1, leptophos, :111d methyl parathion (en- ttsst \vab applied to the treatment mrans. Near1 values capsulated formulation from Pennwalt). Supracide is W~‘I’Vcoll\.erttvl to original units for prchsentation in the now recommended for use 011 1obacco (8 ), registration ta1,k.s. of acephate is pending, and ve5earch with &&an has been discontinued. This report. Ivesen& additional infor- RESULTS AND DISCUSSION mation on t.he performance of leptophos and methyl para- Toh/(.rtr /
5.6 lb/gal EC 8.0b 28.2b Tobacco Science, 1974, 18-31, p. 87-88, ISSN.0082-4523.pdf MC-4044 2 lb/gal EC 1.04 9.9a 8.0~1 5.0a l9.Oa Methomyl I.8 lb/gal L .3a 2.0a .50 l6.2b 13.9b 8.6sc 34.0ab 90% SP 2.2a 2.3a 25 24.3~ 22.9c l5.7c 51.3bc Check 43.le 82.5~ Methomyl 90% SP .5l 8.ba 8.9a 7.0ab 22.5a Check 27.4~ 23.2~ l3.6bc 59.lc Exoeriment 6 lJune 6-16. 1973) Methyl 2 lb/gal E& I.00 l2.6b 8.Oab 4.2a 22.4a parathion .75 l7.9bc I I .9b 9.oa 32.5a Leptaphor 45% WP 1.06 18.6bc lO.bab 8.ba 28. I a .74 l9.9cd I2.Ob 5.4a 35.lab .52 2 I .7cd l2.9b 7.ba 40.8a b Table 3.-Insecticidal control of the tobacco flea beetle on flue-cured Methomyl 90% SP .50 6.4a 5.9a 5.4.a 23.l.s tobacco as measured by number of adult beetles. Clayton, N.C. Check 27.6d 23.bc 18.9b 56.7b Experiment 7 [June 13-23. 1973) Insecticide Formulation No. adult beetles/ 10 plants~ days .6a .6a MC-4044 2 lb/gal ;C .9b .3a after treatment .5l l.8ab 3.0b 3.2ab 5.9bc 5.9b .25 6.8de 3 6 10 5.6 lb/gal EC .5l 2.6bc 2.7b 2.3ab Mathomyl I.8 lbfqal L .5l 5.0cd 3.8b 2.6ab Experiment 1 (Aug. 4-14. 19711 90% 5P .5l IO.le 8.4~ 4.2b MC-4044 2 lb/gal EC 0.49 252.5b 717.2a Check 25.3f 22.bd 17.6~ Methomyl 90% SP .53 118.4.~ 543.a Check 335.3b 592.9.a Exoeriment 2 IJulv 13.23. 1972) 2 Ib/gdl EC ml- 3:2a l5.9ab lb2.3a .50 3.3.a 16.7ab 99.6a .2b 2.2a 14.7ab 225.6a 90% SP .5l 8.2a 192.4a tion in the cotttro] obtained lvith 31(1-4044.(:omparisons 16% 24.2b 141.4a Experiment 3 [July 27.Aug. 6. 1973) based on damage showed that, 1 lb of ;\IC-4044 W:M Methyl pdrathion 2 lb/gal ECh I.01 205.9bc 241.5ab superior to methorny SP in 2 tes:.s and similar in 2, Yz .75 23b.Pc 339.7b :;i::: Leptophos 45% WP .98 lb9.3at , ll4.3a Il4.ld lb of MC-4044 was similar to mrthompl SP in 4 tests .74 l42.ba l56.8a 136.2a .5l I68.8at 156.3a 141.9a and superior in 1, attd ‘~3 lb of p\l(‘-4044 ~vas similar to Methomyl 90% SP .50 223.5~ 358.3b methomyl SP in 2 tests and inferior in 1. Similar con- Check 378.3d 733 3c :7,‘,:;: trol was obtained with 2 lb and 5.6 lb/gal EC formul;t- Experiment 4 (Aug. 3-13. 1973) MC-4044 2 lb/gal EC 31?.,b 278.7a tions of MC-4044 i Eqwrimrttt 711. 249.0a :E;:E 275.6a 5.6 lb/gal EC 294.lab 243.4.a Methomyl I.8 lb/gal L 227.7a 302.l.a 90% SP 27O.ba b 340.8a r\lethomyl SP at ‘3 lb/‘avre cottt rolled larvae atld Check 235.0ab 260.8a damage in all expwimwts (Table 2 1. Methomyl L at ?/z lb was used only in Experiment 3, Lvhere it was slightly but not significantly more effective than methomyl SP. In Experiment. 2, one and ?i 11,of methyl p:trat.hion were as c,fTective as methomyl SP :I and (i days after and 1, V, and % lb of leptopho; \vertx as effrctivc ;~s ;tpplicat iotl. ,Kone of these treatments wduced the in- met.hontyl SP in controlling 1arv:w 3 days aftrr ttwtt- I’estaticbn IO tl:tys after application. One, ?i and !5 lb of ment and in reducing darn;tacL. l)~~l)o~itiott of eggs dur- leptoi)hos ~wluced the infestation for 10 days, and these ing the posttreatmrttl, period resulted in an irtctwtse in I rest mrnts \wt*t’ superior to methomyl SP throughout the larval inftA:ttion in Al twwtntt~nt~ and the check 1)) i his period. the 10th day. The only treatm~~ttts &‘wt ive against In Exp~~rimt~tit 2, one, !A. and Ii lb of MC-4043 were these small larvae were 1, ‘,j, and ‘2 lh of lcptophos. as r,ffect ivt* as mothomyl PP. These MC-4034 trewtmclnts One, l/z, and ‘~4 lb of .\Ic’-1043 \vt~re less effecti\,e t.hatt wrre itlrafl’wti\.e in Experiments I ;Lnd 4. In Experiment methomyl SP against hortt\vornt:: ( Experiments 1 and 4, no sigttificattt difference was noted in the per- 3). In Experiment :<, littIc’ cliffewttcr was noted in the formance IIf t! lb and 5.6 Ibigal EC formulations of performance of 2 lb and 5.6 lb/gal EC‘ formulations of MC--3044. NC-4044.
Methomyl RP at f i lh/act~ retluwd adult beetle itt- festations in all expcsrimvnts f Tal~le 3 1. JIethomyl L ;tt $5 lb was used onlv in Exprrinlcat 4, where it ~~21s slightly bui not ~ian;fic~atrt.ly more effwtive than metho- my1 SP. In Experiment 3, onv and ?i 11,of methyl parathion
(‘Tobacco Science 88)