AERIAL INSECTICIDE CONTROL OF THE SUGARCANE BORER

Transcription

1 AERIAL INSECTICIDE CONTROL OF THE SUGARCANE BORER T. E. Regn, C. D. McAllister, F. R. Posey, T. L. Bcon, nd W.H. White 2 Deprtment of Entomology nd 2 USDA-ARS Sugrcne Reserch Unit, Houm, L. Insecticidl control of the SCB ws evluted in rndomized complete lock design with five replictions using the vriety LCP (Rep -plnt cne, Reps 2-5-first rtoon) t Armlise Plnttion, Belle Rose, L. (Assumption Prish). Tretments were pplied with wter using Recip/Grummn AgCt ircrft (28-foot spry width), clirted to deliver 2 gp. Tretments were rndomly ssigned to field plots rnging in size from 2. to 4.4 cres ech (3-7 swths/plot). All insecticide tretments were pplied with the surfctnt Ltron CS-7 t the rte of.25% vol/vol. SCB infesttions were monitored weekly y rndomly exmining 25 stlks in the center portion of ech plot throughout the seson for live SCB lrve in the lef sheths. Plots were treted when threshold levels were t 5% of the sugrcne stlks infested with lrve in the lef sheths. SCB monitoring continued weekly fter the initil tretment (6 July), nd on 5 August, plots were gin treted. Weekly monitoring continued into Septemer with the SCB popultion never gin reching the threshold. Reltive soil surfce ssocited rthropod undnce ws ssessed using pitfll trps. Three pitfll trps were plced in the center row of ech plot t intervls of -, 2-, nd 4-foot spcings. Contents of the trps in ethylene glycol were collected on 8 August, 3 August, nd 4 Septemer, nd specimens were sorted in the lortory. Confirm-, Krte-, nd Fury-treted plots hd significntly lower percent ored internodes nd percent seson infesttion of SCB thn the untreted check plots (Tle ). Additionlly, oth Krte nd Fury exhiited significntly shorter SCB length of control 29 dys fter tretment sed on weekly infesttion counts. Confirm did not significntly ffect popultions of nts or other nontrget rthropods counted in pitfll trps (Tle 2). Fury- nd Krte-treted plots hd significntly fewer nts thn untreted check plots. Differences were not detected in spider popultions mong ny of the insecticides compred to the untreted check plots. This reserch suggests tht Confirm, Krte, nd Fury effectively control SCB infesttions nd my e used in n effective integrted pest mngement progrm in Louisin sugrcne. All three mterils now hve EPA Section 3 lels for sugrcne orer mngement.

2 Tle. Aeril ppliction insecticide study for control or the sugrcne orer, Armlise Plnttion, Belle Rose, L., 2. Tretment/ formultion Rte (mt/cre) % SCB Live Lvl Infesttion % SCB DAT 7 DAT 24 DAT 29 DAT Seson Infesttion % Bored Internodes Moth Emergence Untreted check ,7. Confirm 2F 8. oz c Krte Z 2. oz Fury.5EC 3.37 oz Mens followed y the sme letter within column re not significntly different (P=.5, LSD). Insecticide tretments were pplied on 6 July nd 5 August. Tle 2. Arthropod undnce in sugrcne field, Armlise Plnttion, Belle Rose, L., 2. Tretment/ formultion Rte mt/cre Seson Arthropod Aundnce Ants Crickets Spiders Untreted check Confirm 2F 8. oz c 3. Krte Z 2. oz Fury.5EC 3.37 oz c 3.7 Mens followed y the sme letter within column re not significntly different (P=.5, LSD). Insecticide tretments were pplied on 6 July nd 5 August.

3 ASSESSMENT OF REGIONAL INSECT PEST MANAGEMENT IN LOUISIANA SUGARCANE, 2 AND 2 T. E. Regn, F. R. Posey, C. D. McAllister, T. L. Bcon, M. E. Slssi 2, nd W. H. White 3 Deprtment of Entomology, 2 Deprtment of Agriculturl Economics & Agriusiness, nd 3 USDA-ARS Sugr Reserch Unit, Houm, L. An experimentl ssessment of insect pest mngement ws conducted in Louisin sugrcne over eight production regions which were selected for comprison of sugrcne orer (SCB), Ditre scchrlis, spring ded herts, SCB nd other insect pest insecticidl controls, end-of-seson ored internodes (nd dult emergence), nd yield. In ech region, two mngement units were chosen to compre: two plnt-cne nd two stule fields in SCB-susceptile vrieties versus moderte or resistnt vrieties. A totl of 7 fields were smpled cross the primry Louisin sugrcne production regions in 2 nd 98 fields in 2. The vrieties smpled were LCP or HoCP9-555 (oth SCB susceptile) nd HoCP85-845, CP7-32, LCP86-454, or LHo83-53 (ll SCB resistnt). Regions included in this survey were s follows: Centrl (Rpides Prish), Southwest (Jefferson Dvis Prish), Upper River (Pointe Coupee nd Ierville prishes), Upper Lfourche (Assumption Prish), Lower Lfourche (Terreonne nd Lfourche prishes), Vermilion (Vermilion nd Lfyette prishes), Teche (St. Mrtin nd Ieri prishes), nd Lower River (St. Jmes Prish). With coopertion from the respective growers, licensed consultnts, nd county gents, spring ded hert smpling, stnd counts, insecticide use, nd end of seson SCB ored internode frequency nd dult emergence holes were compred with the yields of the smpled fields. During the ded hert survey, orer lrve were collected nd rered out for prsite (prsitoid) determintion. Of the 5,35 stlks (65,8 totl internodes) evluted for the eight regions,,33 of the internodes were ored, for totl verge of 2%, nd SCB spring ded herts verged 277 per cre for the 2 growing seson. Results indicted yer of very light insect pressure, with most fields receiving only one or less ppliction of insecticide ecuse of the severity of the drought tht frmers fced during this growing seson. An exception to the drought occurred in the Centrl Louisin region where erly rins were received (Tle compres orer incidence nd control in ove norml rinfll versus drought conditions for ech region), nd some fields required three pplictions for SCB control, with infesttions reching s high s 2% live lrve in the lef sheths. One field surveyed required four pplictions of insecticide. Some of these sme frmers lso were fced with n outrek of the recently discovered sugrcne phid, Melnphis scchri (Zehntner), nd the yellow sugrcne phid, Siph flv (Fores), requiring dditionl insecticide tretments. Regrdless of the trditionl levels of SCB infesttion in ny prticulr sugrcne region, orer infesttions nd need for control were overwhelmingly decresed under reduced rinfll conditions. 2

4 In comprison, of the 3, stlks (39,87 totl internodes) evluted in 2 in the eight regions,,47 of the internodes were ored, for totl verge of 3.7%, with SCB spring ded herts verging 278 per cre. Tles 2 provides nlyzed mens from the ded hert ssessment for ech region during the 2 nd 2 production sesons. Results indicted yer hving closer to norml SCB pressure ecuse of rinfll more evenly spred throughout the regions, with most fields receiving one or less ppliction of insecticide. In few fields throughout the sugrcnegrowing regions, two pplictions of insecticide were required for SCB control. 3

5 Tle. Rinfll nd orer incidence nd control comprison in the eight regions of the Louisin sugrcne industry in 2 nd 2. Selected Regions 2 FEB & MAR Inches of rinfll (+ norml) APR & MAY JUN & JUL AUG & SEP # of Insecticide pplictions % SCB ored internodes Centrl 8.3 (-2.) 2.3 (+3.) 7.5 (-.4) 3. (-5.5) Southwest 2.6 (-5.9) 9.7 (+.) 8.2 (-2.3) 6.5 (-4.). 2.9 Upper River 2.8 (-8.2).9 (-8.2) 8.6 (-.3) 2. (-8.3). 2.8 Upper Lfourche 9.2 (-.). (-8.6) 8. (-5.).5 (-2.3). 2.5c Lower Lfourche 5.7 (-5.).9 (-8.3) 3. (+.6).4 (-3.).2 2.c Vermilion 3. (-5.) 3. (-6.2) 8. (-4.9) 9. (-3.2)..3c Teche 2.5 (-5.7). (-7.7) 2. (-.3) 9.6 (-2.7)..3c Lower River 4.2 (-6.7).2 (-7.9) 6.8 (-5.) 8.9 (-2.8)..7c 2 Centrl 4.7 (+4.4) 4. (-5.2) 2.8 (+3.9). (+2.4)..7 Southwest.2 (+2.6).8 (-7.8) 7. (+6.6) 2.8 (+.2). 2.5 Upper River 4. (+3.) 2.3 (-7.8) 25.7 (+5.8) 2. (+.7) Upper Lfourche 9.4 (+.) 2.7 (-6.9) 28.9 (+5.7) 4.8 (+.) Lower Lfourche 7.8 (-3.).2 (-8.9) 23.9 (+.5) 4.9 (+2.3). 2. Vermilion.8 (+3.6) 3.7 (-5.6) 26.5 (+3.5) 8.7 (+6.6) Teche 2.7 (+4.4) 4.2 (-4.6) 7.6 (+4.3) 24.5 (+2.2).8.8 Lower River 9.7 (-.3) 7.9 (-.) 24.6 (+2.6) 3.2 (+.5) Vlues in prentheses represent the mount the mesured rinfll totl ws ove or elow norml verge Sugrcne orer (SCB) ored internodes vlues represent men of 6 fields evluted in ech region ech yer except the Southwest region, which hd eight fields evluted ech yer, nd mens followed y the sme letter in column for the designted yer re not significntly different (P<.5, LSD). 4

6 Tle 2. SCB ded hert ssessment in the Louisin sugrcne industry in 2 nd 2. SCB Ded Herts Per Acre Selected Regions 2 2 Centrl Southwest Upper River 5 58 Upper Lfourche Lower Lfourche Vermilion Teche Lower River Ech vlue represents men of 6 fields evluted in ech region ech yer except the Southwest region, which hd 8 fields evluted ech yer, nd mens followed y the sme letter in column re not significntly different (P<.5, LSD). 5

7 SUGARCANE BORER MANAGEMENT THRESHOLD ASSESSMENT ON FOUR COMMERCIAL VARIETIES T. E. Regn, F. R. Posey, C. D. McAllister, nd T. L. Bcon Deprtment of Entomology Four sugrcne orer (SCB) insecticide mngement regimes were studied in four repliction rndomized complete lock experiment on ech of four vrieties plnted in the fll of 2 t the Sugr Reserch Sttion, St. Griel, L. The study conducted during the 2 seson ws designed to ssess SCB injury, potentil re-wide moth production, nd yield loss of resistnt nd susceptile vrieties under different intensity levels (different thresholds) of pest mngement. The vriles were the four commercilly grown sugrcne vrieties in Louisin, () SCB resistnt (CP7-32, HoCP85-845) nd susceptile vrieties (LCP85-384, HoCP9-555) nd (2) four regimes of SCB insecticidl control (sed on 5% nd/or % lrvl SCB infesttion thresholds nd non tretment threshold). SCB lrvl infesttions were monitored weekly with lef sheth smpling. Plots (. cre, three rows ech) were treted when infesttion levels reched the designted threshold levels set y the indicted tretment regimes. Confirm (teufenozide), with the surfctnt Ltron CS-7, ws tnk mixed t the rte of 6 oz/cre nd.25% vol/vol, respectively. All three rows in ech plot were treted using CO 2 spryer mounted on n ll-terrin vehicle. The spry oom covering two rows on one side nd one row on the other contined one flt fn spry nozzle per 6 feet of row width t GPA nd 35 psi. Infesttions were ssessed on the two outside rows, nd the integrity of the center row ws preserved for yield evlution. In ddition, ecuse of enhnced experimentl vriility cused y nturlly occurring rthropod predtion, especilly from fire nts, two pplictions of the soil pesticide chlorpyrifos (Lorsn ) were rodcst for rthropod predtor suppression t the soil level. Dt collected included numer of ded herts per cre (sugrcne shoots killed y SCB lrve), percent SCB ored internodes, SCB dult moth emergence, nd yield loss. Dt were nlyzed using PROC GLM with mens seprted y LSD. As shown in Tle nd Figures nd 2, when using the >5% SCB infesttion threshold (5%) or the 5% erly nd % lte threshold (5%/%), differences were not detected in percent ored internodes or verge percent infesttion. There were different numers of pplictions of insecticide required to control SCB infesttions nd reduced infesttion levels elow the designted thresholds in this study. The vriety HoCP9-555 (highly susceptile) required three pplictions of insecticide during the growing seson for 5% nd 5%/% mngement regimes. In comprison, LCP (susceptile) required three insecticide pplictions for the 5% mngement threshold, ut only two insecticide pplictions for the 5%/% mngement threshold. The resistnt vriety HoCP required two pplictions in the lte prt of the seson for the 5% threshold nd only one ppliction in the lte prt of the growing seson for the 5%/% threshold. CP7-32 required only one ppliction mde in the lte prt of the growing seson under the 5% nd the 5%/% mngement regimes. The verge seson percentge of SCB infesttion ws similr on the 5% nd 5%/% mngement thresholds for ll vrieties (Tle 2). Moth emergence ws significntly higher for vriety HoCP9-555 t the % threshold thn for ll other vrieties t the 5% nd 5%/% mngement thresholds. 6

8 Mngement Regimes Non-Treted Monitoring y Vriety (Check) 5% SCB Mngement Threshold y Vriety Percent HoCP CP7-32 LCP HoCP c c Percent HoCP CP7-32 LCP HoCP # of Applictions % Bored Internodes % Reduction S/A # of Applictions % Bored Internodes % Reduction S/A 5%/% SCB Mngement Threshold y Vriety % SCB Mngement Threshold y Vriety 4 HoCP CP7-32 LCP HoCP HoCP CP7-32 LCP HoCP Percent # of Applictions % Bored Internodes % Reduction S/A Percent # of Applictions % Bored Internodes % Reduction S/A Figure. Mngement threshold y sugrcne vriety showing the vrious prmeters studied. % Reduction S/A= Percent reduction in sugr/cre. Mens followed y the sme letter within ech group re not significntly different, (P<.5, LSD). Economic Injury Level for SCB on sugrcne hs generlly een considered round the % level of ored internodes.

9 Vrieties HoCP 9-555: SCB highly Susceptile LCP : SCB Susceptile Percent % 5%/% % Check 5% 5%/% % Check c c # of Applictions % Bored Internodes % Reduction S/A : Modertely Resistnt HoCP : SCB Resistnt Percent # of Applictions % Bored Internodes % Reduction S/A CP 7-32 Percent % 5%/% % Check # of Applictions % Bored Internodes % Reduction S/A 3.3 Percent % 5%/% % Check # of Applictions % Bored Internodes % Reduction S/A Figure 2. Represents sugrcne vrieties under different SCB lrvl mngement thresholds. The ove legend tretment thresholds in order re: greter thn 5% seson-long mngement threshold; greter thn 5% erly-seson nd greter thn % lte-seson mngement threshold; greter thn % seson-long mngement threshold; non-treted monitoring y vriety (Check). % Reduction S/A = Percent reduction in sugr/cre. Mens followed y the sme letter within ech group re not significntly different, (P#.5, LSD). Tle. Seson-long sugrcne orer injury ssessment, St. Griel Sugr Reserch Sttion, St. Griel, L., 2.

10 Vriety Tretment Mngement Numer of Insecticide Applictions % Bored Internodes c,d Estimted % Yield Loss e /Acre Moth Emergence f/ Acre Dedherts g /Acre HoCP % 2 2.8f.8g 5 LCP % 3 4.7ef 3.2fg 25 HoCP % 3 5.ef 5.efg HoCP %/% 5.6ef 3.7efg 25 5 HoCP %/% 3 6.3def 6.3efg 5 CP7-32 5% 6.4def 4.4efg 5 75 HoCP % 8.def 5.3efg 5 LCP %/% 2 8.def 5.5efg 55 CP7-32 % 9.7cdef 6.6efg 6 75 HoCP Non-treted --.5cde 6.9efg 4 5 CP7-32 5%/%.6cde 7.9def 4 75 LCP % 2 3.6cd 9.4cde 25 HoCP9-555 % 6.5c 6.5c 45 CP7-32 Non-treted cd LCP Non-treted c 5 HoCP9-555 Non-treted Susceptile vrieties include HoCP9-555 nd LCP85-384; resistnt vrieties include HoCP nd CP7-32; Mngements re s follows: 5%: Greter thn 5% SCB mngement threshold over entire seson; 5%/%: Greter thn 5% SCB mngement threshold erly seson nd greter thn % SCB mngement threshold lte seson; Non-treted: Never treted; %: Greter thn % SCB mngement threshold over entire seson; c 25 stlks per plot were evluted for ored internodes; d Mens within column followed y the sme letter re not significntly different (P#.5, LSD); e Moth emergence reflects numer of moths per cre; f Sugrcne shoots killed y SCB; g Estimted percent yield loss ws clculted using conversion fctors from White 2, sed on per internode sis.

11 Tle 2. Seson-long sugrcne orer infesttion with respect to different economic threshold levels nd sugrcne vrieties, St. Griel Sugr Reserch Sttion, St. Griel, L., 2. Tretment Insecticide Percent SCB Lrvl Infesttion Smple Dtes Appliction Dte Vriety Mngement 6 Jul 6 Jul 26 Jul 9 Aug 2 Aug 3 Sept HoCP % Jul 6, Aug 24, Sep cd LCP % Jul 7, Aug 24, Sep d HoCP % Aug 24, Sep cd CP7-32 5% Aug d HoCP %/% Jul 6, Aug 24, Sep cd LCP %/% Jul 7, Sep cd HoCP %/% Sep cd CP7-32 5%/% Sep cd HoCP9-555 Non-treted c LCP Non-treted HoCP Non-treted cd CP7-32 Non-treted HoCP9-555 % Sep LCP % Aug 24, Sep cd HoCP % Aug d CP7-32 % Sep cd Percent live lrve sed on 4 stlks/tretment. Mngements re s follows: 5%: Greter thn 5% SCB mngement threshold over entire seson; 5%/%: Greter thn 5% SCB mngement threshold erly seson nd greter thn % SCB mngement threshold lte seson; Non-treted: Never treted; %: Greter thn % SCB mngement threshold over entire seson. c Susceptile vrieties include HoCP9-555 nd LCP85-384; resistnt vrieties include HoCP nd CP7-32. d Mens within column followed y the sme letter re not significntly different y LSD (P#.5).

12 SMALL PLOT ASSESSMENT OF INSECTICIDES AGAINST THE SUGARCANE BORER T. E. Regn, F. R. Posey, C. D. McAllister, nd T. L. Bcon Deprtment of Entomology Nine insecticide tretments were evluted for control of SCB in rndomized complete lock design with six replictions in field of first rtoon LCP sugrcne t the LSU AgCenter Sugr Reserch Sttion, St. Griel, L. (Ierville Prish). Insecticide tretments were pplied to 3-row plots (6 ft x 4 ft) using CO 2 spryer mounted on n ll-terrin vehicle with n 85 flt fn nozzle (one nozzle per row) delivering 2 gp t 35 psi. Prior to test initition, Lorsn 5G (5 l/cre) ws pplied on July to suppress fire nt predtion on SCB lrve. Initil insecticide tretments were mde on 7 July when SCB infesttions reched the Louisin Coopertive Extension Service recommended threshold (5% of the stlks infested with SCB lrve in the lef sheths). Second pplictions were mde on 2 August when re-infesttion reched 5% in the Confirm 2F treted plots. SCB dmge ws ssessed y counting ored internodes, moth emergence holes, nd totl numer of internodes per stlk from 9 rndomly selected stlks (5 stlks/plot) in ech tretment (8 Novemer). The study site received 6.54 nd 6.35 inches of rinfll during the evlution period of July nd August respectively. Following ANOVA, mens were seprted with LSD. All insecticide tretments significntly reduced % ored internodes compred to the check, ut the Dimilin-treted plots displyed higher percentge of ored internodes thn the other tretments. Plots treted with Krte demonstrted significntly lower % ored internodes thn plots treted with Intrepid t 4. oz/a nd Dimilin. All insecticide tretments hd significntly fewer moth emergence holes/cre thn the untreted check. As result of this reserch, oth Dimilin nd Intrepid hve een discontinued from further considertion for SCB control in Louisin mngement progrms. Fury received permnent Section 3 lel in the fll of 2. Tle. Effect of smll plot insecticidl test on (SCB) Ditre scchrlis (F.), St. Griel Reserch Sttion, 2. Tretment /formultion Rte (i/cre) % Bored internodes No. of exit holes/cre Krte Z.92 oz 6.2d 556 Bythroid 2E 2. oz 6.7cd 2,777 Fury.5EC 3.2 oz 6.7cd 556 Isomer.8EC.6 oz.4cd 5,556 Intrepid 2F 6. oz.7cd 5,556 Confirm 2F 8. oz 2.4cd 2,778 Intrepid 2F 4. oz 2.7c 2,222 Dimilin 2L 8. oz ,333 Untreted Check , Mens within column followed y the sme letter re not significntly different (P<.5, LSD). All tretments were pplied with Ltron CS-7 t.25% vol/vol. Numer of exit holes reflects moth emergence. 2

13 VARIETAL RESISTANCE RESEARCH WITH THE SUGARCANE BORER T. E. Regn, F. R. Posey, K. P. Bischoff 2, K. A. Grvois 2, C. D. McAllister, nd T. L. Bcon Deprtment of Entomology nd 2 Sugr Reserch Sttion Sugrcne resistnce to the sugrcne orer (SCB), Ditre scchrlis, is ctegorized s comintion of physicl chrcteristics tht hinders oring ( rind hrdness, lef-sheth ppression), vriety specific tolernce to oring, nd ntiiosis mechnisms tht contriute to differences in survivl of ored in lrve. The extent of this resistnce lso is influenced y the severity of infesttions. Hevy orer pressure results in more ored internodes, even in vrieties considered highly resistnt. Severl fctors contriuting to sesonl re-wide SCB infesttion levels include wether conditions, predtor nd prsite numers, nd indigenous orer popultions. Expnsive crege of cultivrs with elevted moth production increses endemic SCB popultions nd imposes dditionl pressure on the remining crege of resistnt vrieties. This is of prticulr significnce in mjor periods of lte summer nd fll SCB uildup, such s ws experienced in most of the industry during 2. For this reson, we lso report moth production for ech cultivr in these tests. Test plots for ssessing SCB vrietl resistnce in the 998 HoCP nd 999 L series experimentl vrieties cultivrs, nd four commercil vrieties, were plnted Septemer 22, 2, t Glendle Plnttion, Killon, L. A rndomized lock design replicted four times ws used with ech lock contining two plots of the commercil vrieties CP7-32, LHo83-53, HoCP9-555, nd LCP85-384, nd one plot for ech lock of the HoCP-98 nd L-99 cultivrs. No chemicl controls for SCB were pplied in the test, nd nturl control from fire nts ws suppressed y pplying grnulr Lorsn in lte June. A 5-stlk smple ws cut from ech plot on Octoer 25, 2, (four replictions = 6 stlks ech of HoCP-98 nd L-99 vrieties nd 2 stlks per commercil cultivr). Smple stlks were exmined to determine the numer of ored internodes, moth emergence holes, nd the totl numer of internodes. Experimentl vriety L99-23 hd the most ored internodes (28.9%) nd the highest moth production, with 7,347 moths per cre produced. Commercil vriety HoCP9-555 lso hd higher level of ored internodes t 8.4%. LHo83-53 hd the lowest ored internodes (8.2%), followed y CP7-32, nd LCP t 9.9% nd 2.%, respectively. Becuse of low SCB popultions cused y drought conditions in 2, the test plot for ssessing SCB vrietl resistnce in the 997 HoCP nd 998 L series vrieties, nd three commercil vrieties plnted Septemer 22, 999, t Glendle Plnttion, Killon, L., ws ressessed in the first stule stge in 2. A rndomized lock design replicted four times ws used with ech lock contining two plots of the commercil vrieties CP7-32, HoCP85-845, nd LCP nd one plot for ech lock of the HoCP-97 nd L-98 vrieties. No chemicl controls for SCB were pplied in the test, nd nturl control from fire nts ws lso suppressed y pplying grnulr Lorsn in lte June. A 5-stlk smple ws cut from ech plot on Octoer 2, 2, (four replictions = 6 stlks per ech of HoCP-97 nd L-98 cultivr nd 2 stlks per commercil cultivr). Smple stlks were exmined to determine the numer of ored internodes, moth emergence holes, nd the totl numer of internodes. 22

14 Experimentl vriety L98-27 nd commercil vriety LCP hd the most ored internodes (7.8% nd 5.2%, respectively). L98-29 nd HoCP hd the highest moth production t,652 nd, moths per cre produced, respectively. HoCP97-69 hd the lowest ored internodes (2.%), followed y L98-29 nd HoCP t 2.3% nd 3.%, respectively. Host plnt resistnce to trget pest insects remins n importnt component of the sugrcne IPM system providing growers with proven methodology for minimizing the economic impct of the sugrcne orer. Resistnt vrieties reduce pest dmge t little or no cost to the grower. Our reserch now provides dditionl ssessment criteri for selecting resistnt cultivrs. Incorporting the cultivr s pest survivl rting etter llows us to flg vrieties tht will enhnce SCB popultions in n re. Quntifying the impct of dult SCB emergence involves little dditionl dt collection nd enhnces the efficiency nd vlue of the entomologicl component in sugrcne reeding nd vrietl development t the LSU Agriculturl Center. Acknowledgment: The sugrcne entomology progrm would like to express pprecition for help from other memers of the sugrcne vriety development nd reeding progrm for their ssistnce in cutting the seed-cne, plnting, nd hrvesting the plots. Additionlly, Dr. W. H. White (USDA-ARS) provided the USDA vrieties used in these studies. 23

15 Tle. Vriety Sugrcne orer dmge nd moth production on 998 HoCP series, 999 L series vrieties, nd four commercil vrieties during 2, Glendle Plnttion, Killon, L. Test ws plnted Septemer 22, 2, nd smples cut Octoer 25, 2. % Bored internodes Stlks/cre Moths/cre production L ,89 7,347 HoCP ,386 2,735c L ,889 5,482 TUCCP ,24,54cd L c 4,296,47cd HoCP cd 3,429 6,24cd L cd 48,96,42cd LCP cd 43,523 3,627cd CP d 33,24 3,45d LHo d 34,326 2,288d Mens followed y the sme letter re not significntly different (P <.5, LSD). Stnd counts provided y Dr. Kenneth Grvois, Sugr Reserch Sttion. Tle 2. Sugrcne orer dmge nd moth production in first stule 997 HoCP series, 998 L series vrieties, nd three commercil vrieties during 2, Glendle Plnttion, Killon, L. Test ws plnted Septemer 22, 999; first stule smples hrvested Octoer 25, 2. Vriety % Bored internodes Stlks/cre* Moths/cre production L ,934 9,656 LCP ,85 7,89 CP ,493 8,373 HoCP ,799, L ,63,652 HoCP ,56 6,76 Mens followed y the sme letter re not significntly different (P <.5, LSD). Stnd counts provided y Dr. Kenneth Grvois, Sugr Reserch Sttion. 24

16 EVALUATION OF LOUISIANA SUGARCANE VARIETIES AGAINST TWO EXOTIC INSECT PESTS CAUSING ECONOMIC DAMAGE IN TEXAS. T.E. Regn, B.L. Legendre 2, M. Setmou 3, nd M.O. Wy 3 Deprtment of Entomology, 2 Louisin Coopertive Extension Service, 3 Texs A&M Reserch nd Extension Centers t Weslco nd Beumont, respectively. The Mexicn rice orer (MRB), Eoreum loftini (Dyr), is potentilly serious thret to rice nd sugrcne in Texs nd Louisin. In 98, MRB ws discovered from Mexico in the Lower Rio Grnde Vlley (LRGV) of Texs, nd it immeditely ecme serious pest of sugrcne, cusing complete crop filure in some fields. Since invding the Texs rice elt (TRB) in the lte 98s, the MRB hs ecome n incresingly severe prolem. A recently completed insecticide experiment in rice sustined 5% yield loss in untreted plots. Sugrcne yield loss studies t Weslco hve shown tht 25% MRB ored internodes cuses s much s $25 economic loss in sugr per cre. Without dequte controls, the MRB is on the verge of ecoming mjor prolem to these multi-stte griculturl systems. In view of the poor history of reserch success on iologicl control nd insecticides to control MRB, proctive efforts were undertken to plnt nd ssess the reltive resistnce to MRB exhiited y four Louisin recommended commercil vrieties (LCP , HoCP , CP 7-32, nd HoCP 9-555) nd fifth former Louisin vriety (NCo 3) tht ws plnted s susceptile check. Both NCo 3 nd CP 7-32 re currently grown in LRGV s commercil vrieties. There were six replictions of ech vriety (ech plot one row y 2 foot long) in this experiment conducted t the Weslco Sttion Annex. The vrieties LCP , HoCP , nd HoCP were trnsported disese- nd insect-free from Louisin. No insecticide ws used during the growing seson. However, there ws irrigtion t regulr intervls, which tended to cuse the experiment to e less ttrctive to MRB. The percent MRB ored internode ssessment of vrieties in this experiment (plnted /2/) evluted on // using Tily stlk-splitting mchine is shown in Tle. It is noted tht the reltive dult (moth) emergence vlues (distinguished y n ovl-shped exit hole on the stlk) lso re presented for this MRB ssessment. Tle. Susceptiility of Louisin commercil vrieties to the Mexicn rice orer, Weslco, TX, 2. Vriety % Bored internodes Moth emergence/cre HoCP LCP NCo c CP c HoCP c Lest Significnt Difference Mens within column followed y the sme letter re not significntly different, LSD P<.5. A rndomized complete lock design with five replictions, nd 2 stlks/plot ws used. 25

17 Both sugrcne orer (SCB) susceptile vrieties (HoCP nd LCP ) re lso susceptile to MRB, with LCP significntly more susceptile thn the previously known MRB highly susceptile NCo 3 (when moth emergence is considered). HoCP is significntly more MRB resistnt thn either LCP or HoCP The sugrcne lce ug, Leptodicty tid (Herrich-Scheffer) (Hemipter: Tingide), is present on sugrcne in Florid, Texs, nd Hwii, s well s in numerous countries throughout the Crien re. It is often considered reltively minor insect pest. However, t times, numers of this lef-feeding, sp-sucking insect cn ecome high enough to cuse entire fields in region to pper ple green, with n ovious impct on photosynthesis. These conditions, sometimes verging over lce ugs per plnt, were present in severl res of LRGV of Texs in lte July nd erly August of 2. Assessment of lce ug infesttions (oth immture nymphs nd dults) on the test of Louisin sugrcne vrieties ws initited in the lst week of July, with dt summrized s shown in Tle 2. Tle 2. Louisin sugrcne vrietl susceptiility to the sugrcne lce ug (Tingide) in studies t the Weslco Texs A&M Reserch Sttion Annex, July, 2. Vriety % Plnts Infested Totl dults nd nymph 2 % Nymphs 3 (immtures) NCo c c CP LCP c c HoCP HoCP plnts smpled (ll leves) in ech plot. Six-repliction experiment with 2 ft. one-row plots. Mens within ech column followed y the sme letter re not significntly different, (P<.5, LSD). 2 Adult nd nymph forms per 5 plnts smpled in ech plot. 3 % in nymphl stge of totl numer of lce ugs counted. Vrietl differences were oserved showing tht sustntilly fewer lce ugs occurred in HoCP 9-555, which ws more resistnt thn vriety NCo 3 nd LCP Dt included oth plnt nd lef infesttion levels, lce ug densities per plnt, nd the proportion of immture (nymphl stge) to totl lce ug infesttion numers. The sustntilly reduced proportion of immtures in HoCP ws n indiction of plnt resistnce. The sugrcne lce ug hs not een oserved in Louisin sugrcne or in the,-cre production ner Beumont, Texs. 26

18 MONITORING MOVEMENT OF THE MEXICAN RICE BORER TOWARD SUGARCANE AND RICE IN THE UPPER TEXAS RICE BELT AND WESTERN LOUISIANA, AND EVALUATION OF INSECTICIDE MANAGEMENT OPTIONS T. E. Regn, M. O. Wy 2, nd F. R. Posey Deprtment of Entomology nd 2 Texs Agriculturl Reserch nd Extension Center 59 Aggie Drive, Beumont, TX 7773 As follow-up to pheromone trp smpling for the Mexicn rice orer (MRB), Eoreum loftini (Dyr) (Lepidopter: Crmide), djcent to sugrcne fields in Southest Texs nd Southwest Louisin in 2, coopertive studies etween Texs A&M nd the LSU AgCenter were undertken in the summer nd fll of 2 to define the insect s present rnge. Using twice weekly monitoring of pheromone trps in nine Texs counties nd seven Louisin prishes, new MRB loctions were found in Austin nd Hrris counties in Texs. (See Figure for reltive loctions). The insect still is not known to occur in Louisin, ut it now ppers in reltively high popultions within 5-6 miles of the new sugrcne production re ner Beumont, Texs, (Austin, Hrris Clhoun, Colordo, Jckson, Mtgord, nd Whrton counties), nd within 2 miles of sugrcne in Southwest Louisin (See Tle ). In ddition to pheromone trp ssessment, lrvl infesttions in rice nd other grsses hve een discovered in mny of the newly invded res. In ddition to extensive prticiption y Texs rice elt county gents, western Louisin sugrcne prish gents, personnel from oth the Texs Deprtment of Agriculture (S.S. Nilkhe) nd the Louisin Deprtment of Agriculture nd Forestry (Td Hrdy) supervised collection efforts. Mngement studies involving vrietl resistnce nd insecticide control lso were ssessed with coopertors in the USDA, LSU AgCenter, nd Texs A&M Systems, s well s with chemicl industry collegues nd the Rio Grnde Vlley Sugr Growers Assocition. The most promising MRB pesticidl controls in sugrcne, though indequte compred to the sugrcne orer stndrds, were cyfluthrin (Bythroid ) nd the ecdysone gonist teufenozide (Confirm ). Replicted vriety ssessment to determine reltive MRB resistnce of rice nd sugrcne hs shown t lest 4.5-fold differences in susceptiility mong selected commercilly ville vrieties. MRB hs proven to e very severe pest of sugrcne in South Texs nd Mexico, nd it would e n especilly serious prolem to Louisin growers under drought conditions similr to those experienced in recent yers (prticulrly ecuse most of the Louisin growers hve no fcility to irrigte). 27

19 Tle. Pheromone trp collections of Mexicn rice orer (Eoreum loftini) moths in Southest Texs during 2. Texs Counties My June July August Septemer Octoer Novemer New Discovery Austin Hrris Previously Known Counties Clhoun Colordo Jckson Mtgord Whrton No MRB Collected Lierty Ornge Numer of moths per two trps per month. Moths were removed from trps twice weekly; pheromone lures nd insecticide strips were replced monthly. 28

20 Figure. Mp of Mexicn Rice Borer Pheromone Trpping in the Min Texs Rice Are (Southest Texs), 2.