Quantifying Efficacy and Avoidance Behavior by Tawny Mole Crickets (Orthoptera: Gryllotalpidae: Scapteriscus vicinus) to Three Synthetic Insecticides

Transcription

1 Quntifying Efficcy nd Avoidnce Behvior y Twny Mole Crickets (Orthopter: Gryllotlpide: Scpteriscus vicinus) to Three Synthetic Insecticides Authors: D. E. Silcox, C. E. Sorenson, nd R. L. Brndenurg Source: Florid Entomologist, 95(1) : Pulished By: Florid Entomologicl Society URL: BioOne Complete (complete.bioone.org) is full-text dtse of 200 suscried nd open-ccess titles in the iologicl, ecologicl, nd environmentl sciences pulished y nonprofit societies, ssocitions, museums, institutions, nd presses. Your use of this PDF, the BioOne Complete wesite, nd ll posted nd ssocited content indictes your cceptnce of BioOne s Terms of Use, ville t Usge of BioOne Complete content is strictly limited to personl, eductionl, nd non-commercil use. Commercil inquiries or rights nd permissions requests should e directed to the individul pulisher s copyright holder. BioOne sees sustinle scholrly pulishing s n inherently collortive enterprise connecting uthors, nonprofit pulishers, cdemic institutions, reserch lirries, nd reserch funders in the common gol of mximizing ccess to criticl reserch.

2 Silcox et l.: Mole Cricket Avoidnce Behvior to Synthetic Insecticides 63 QUANTIFYING EFFICACY AND AVOIDANCE BEHAVIOR BY TAWNY MOLE CRICKETS (ORTHOPTERA: GRYLLOTALPIDAE: SCAPTERISCUS VICINUS) TO THREE SYNTHETIC INSECTICIDES D. E. SILCOX, C. E. SORENSON, AND R. L. BRANDENBURG Deprtment of Entomology, North Crolin Stte University, Cmpus Box 7613, Rleigh, NC ABSTRACT Mole crickets (Orthopter: Gryllotlpide) re mong the most economiclly importnt turfgrss insect pests in the southestern United Sttes. The twny mole cricket Scpteriscus vicinus (Scudder) cuses dmge y feeding on the roots nd shoots of turfgrss nd y creting surfce tunnels. Previous reserch on mole cricket control showed ehvior modifiction, including reduced surfce tunneling nd voidnce of the treted soil, when control gent ws pplied. The ojectives of these studies were: ) to determine the mortlity of 3 synthetic insecticides nd their residues ginst smll nd lrge mole cricket nymphs in 2 iossys nd ) to monitor mole cricket ehviorl responses to these insecticides. We used 3 synthetic insecticides (ifenthrin, chlorntrniliprole, nd fipronil) to conduct 2 mortlity iossys nd 2 ehviorl studies, where we quntified surfce tunneling, to determine the scope of this modified ehvior. We found tht, in generl, the greter the efficcy of the product to mole crickets, the greter the likelihood of reduced surfce tunneling nd voidnce of the treted re. These studies confirm tht mole crickets void n re treted with insecticide nd emphsize the importnce of pproprite timing of insecticides to chieve effective control of mole crickets. Key Words: Scpteriscus vicinus, voidnce, insecticide control, mngement RESUMEN Los grillotopos (Orthopter: Gryllotlpide) se encuentrn entre ls plgs de insectos del césped de myor importnci económic pr el sureste de Estdos Unidos. El grillotopo leondo, Scpteriscus vicinus (Scudder), cus dño l limentrse de ls ríces y los rotes de césped y por l creción de túneles en l superficie. En un investigción nterior sore el control de grillotopos, se oservó l modificción de conduct, incluyendo l reducción de túneles en l superficie y el evitr el suelo trtdo, donde un gente de control fue plicdo. Utilizmos tres insecticids sintéticos pr relizr dos ioensyos y dos estudios de comportmiento pr determinr el lcnce de este comportmiento modificdo. Hemos encontrdo que, en generl, cunto myor es l toxicidd gud del producto los grillotopos, myor será l proilidd de l repelenci y reducción de túneles en l superficie. Estos estudios confirmn que los grillotopos evitn un áre trtd con insecticid y hce hincpié en l importnci de l plicción de insecticids en un tiempo propido pr logrr un control eficz de los grillotopos. The twny mole cricket Scpteriscus vicinus (Scudder) is one of the most destructive soildwelling, turfgrss insect pests in the southestern United Sttes (Brndenurg 1997). Mole crickets cuse dmge y feeding on the roots nd shoots of turfgrsses nd through extensive soil tunneling (Brndenurg et l. 2000). The tunnel structure provides useful informtion out the ehvior nd ecology of this pest (Brndenurg et l. 2002). In North Crolin, the twny mole cricket is univoltine, with the overwintering dults ovipositing in lte Apr-My nd egg htch occurring in Jun nd Jul. The newly-emerged nymphs egin feeding on the turfgrss; however dmge is not redily visile erly in the seson, since the turfgrss is ctively growing nd the crickets re smll. While the smller crickets re more susceptile to control gents, nd their ility to tunnel is limited, control is often delyed ecuse dmge is not visully evident. As the nymphs grow nd feed more extensively, dmge ecomes more pprent y mid-aug. By the time dmge is pprent, the mole crickets re more difficult to control thn erly instr nymphs. A full understnding of pest iology, including nymph ehvior, could therefore enhnce mngement (Brndenurg et l. 2000). Mole crickets hve een oserved modifying their tunneling ehvior in soil treted with either conventionl, iologicl insecticidl control gent, or nturlly-occurring soil fungi (Brndenurg et l. 2000; Villni et l. 2002). The modified ehviors included reduced surfce ctivity nd voidnce of treted res. Susequent studies

3 64 Florid Entomologist (95)1 Mrch 2012 using entomopthogenic fungl conidi nd the synthetic insecticides ifenthrin (Thompson & Brndenurg 2005; Thompson et l. 2007) found similr chnges in tunneling ehvior. A study on fipronil degrdtion in soils found tht mole crickets would escpe continers treted with high rtes of fipronil nd remin in control continers (Cummings et l. 2006). Since chnges in tunneling ehvior could drmticlly ffect insect control nd turf dmge, dditionl reserch on mole cricket ehvior ws conducted using the synthetic insecticides ifenthrin, chlorntrniliprole, nd fipronil in 2008 nd The ojectives of these studies were: ) to determine the mortlity of 3 synthetic insecticides nd their residues ginst smll nd lrge mole cricket nymphs in 2 iossys nd ) to quntify mole cricket ehviorl responses to these insecticides. These studies were conducted to quntify mole cricket voidnce ehvior nd surfce tunneling in response to insecticide ppliction nd increse our knowledge of pest ecology. MATERIALS AND METHODS Insecticide iossy nd ehviorl studies were conducted in North Crolin Stte University greenhouse fcilities nd t the Lke Wheeler Turfgrss Field Lortory in Rleigh, NC, in 2008 nd Mole crickets used in these studies were collected on golf course firwys nd driving rnges using sopy wter flushes (Short & Koehler 1979). All collected crickets were rinsed immeditely in wter nd plced in 68 liter storge ox (Ruermid Newell Ruermid Inc., Atlnt, Georgi) filled with ntive soil (Norfolk series, fine sndy lom, deep phse, HM = 0.66%, ph = 4.1, CEC = 3.2) from mole cricket collection site (Olde Fort Golf Course, Brunswick Co., North Crolin) with no history of pesticide ppliction. Ntive soil ws used to keep the ehvior of mole crickets in experiments s nturl s possile. Mole crickets were collected no erlier thn week prior to use in ny study. In 2008, mole crickets were collected from Emerld Golf Clu in Crven Co., North Crolin, Scotch Medows Country Clu in Scotlnd Co., North Crolin, nd Belvedere Country Clu in Pender Co., North Crolin nd in 2009 from Belvedere Country Clu in Pender Co., North Crolin nd Scotch Medows Country Clu in Scotlnd Co., North Crolin. The following formulted insecticides were used in ll experiments: grnulr ifenthrin (Tlstr EZ, FMC Corp., Phildelphi, Pennsylvni), spryle chlorntrniliprole (Acelepryn, DuPont Professionl Products, Wilmington, Delewre), or grnulr fipronil (Chipco Choice, Byer Environmentl Science, Montvle, New Jersey). All insecticides were pplied t 2 rtes: ifenthrin t kg i/h (stndrd) or kg i/ h (high); chlorntrniliprole t kg i/h (stndrd) or kg i/h (high); nd fipronil t kg i/h (stndrd) or kg i/h (high). s were scheduled 0, 30, 60, or 90 d prior to plcement of crickets in the treted continers to provided post-tretment intervls tht llowed for evlution of mortlity nd ehvior not only to the prent compound, ut to ny residues or metolites of the compound. All tretment pplictions were mde to re soil. All soil ws from the sme loction nd continers were mintined in similr mnner so tht ehvior would not e ised due to soil conditions. The grnulr formultions of ifenthrin nd fipronil were weighed nd evenly distriuted cross the soil surfce using shker jr with gloved hnd. Cre ws tken to ensure uniform distriution. An queous preprtion of chlorntrniliprole ws pplied using Delt Oritl 360 Spryer(Delt Industries, King of Prussi, Pennsylvni) delivering pproximtely 6,830 liters/ h for the stndrd rte nd 13,661 liters/h for the high rte pplying 5 ml of solution for iossy continers nd 10 ml of solution for choice continers (Delt Industries, King of Prussi, Pennsylvni). Insecticide Mortlity Biossy I: Smll Nymphs Biossy I used smll ( cm) twny mole cricket nymphs to determine mortlity of the previously mentioned insecticides. For Biossy I, one liter plstic Ziploc continers ( cm, SC Johnson, Rcine, Wisconsin) with 5 dringe holes (0.5 cm dimeter) were filled to depth of 5.08 cm with ntive soil (Norfolk, fine sndy lom, deep phse, HM = 0.66%, ph = 4.1, CEC = 3.2) from the Olde Fort mole cricket collection site. Insecticide pplictions were mde in 2009 on 16 Jul, 20 Jul (0 d), 6 Jun (30 d), 19 My (60 d), nd 20 Apr (90 d) to produce desired intervls in post tretment exposure when mole crickets were exposed to treted soil (Tles 1 nd 2). There were 5 replictes per tretment. Uncovered continers were plced outdoors immeditely fter soil tretments to expose them to mient tempertures, rinfll, nd sunlight, llowing for typicl pesticide degrdtion on re soil. The monthly verge tempertures for the durtion of this experiment were s follows: Apr: C, My: C, Jun: C, nd Jul: C. The monthly totl rinfll for the durtion of this experiment ws s follows: Apr: 2.77 cm, My: 9.60 cm, Jun: cm, nd Jul: 8.36 cm. To mintin reltively stle mient conditions ( C) during the evlution period, continers were rought into the lortory t the Lke Wheeler Turfgrss Field Lortory one d efore cricket plcement. A single, smll nymph, collected on either 9 Jul or 15 Jul, ws plced in ech continer t the onset of the evlution pe-

4 Silcox et l.: Mole Cricket Avoidnce Behvior to Synthetic Insecticides 65 riod nd lid perforted with five cm holes ws plced on top of the continer. A cm cm piece of fierglss screen (Phifer Inc., Tuscloos, Alm) ws secured round the ottom of the continer to prevent mole cricket escpe through the dringe holes. To evlute mortlity, the contents of ech continer were sifted dily y using spoon to excvte the soil for 3 d fter initil cricket plcement (17 Jul Jul 2009 nd 21 Jul Jul 2009). Evlution 1 pertins to mortlity recorded 1 d fter exposure (DAE) nd evlution 2 pertins to mortlity recorded 3 DAE. Insecticide Mortlity Biossy II: Lrge Nymphs Biossy II used lrge ( cm) twny mole cricket nymphs to determine the mortlity of the previously mentioned insecticides. The iossy ws conducted with the sme tretments nd mterils s the first iossy of smll nymphs. pplictions were mde in 2009 on 10 Aug nd 22 Aug (0 d), 6 Jul (30 d), 6 Jun (60 d), nd 6 My (90 d) to produce the desired intervls in post tretment exposure when mole crickets were exposed to treted soil. The verge temperture in Aug ws C nd the totl rinfll ws 5.46 cm (dt for the other months were mentioned previously). A single lrge nymph collected either on 5 Aug, 9 Aug, 16 Aug, or 20 Aug ws plced in ech continer t the onset of the evlution period. The tretment nd plcement of crickets in the 0 d tretment of the stndrd rte continers ws delyed 5 d from the 30, 60, nd 90 d tretments of the stndrd rte continers due to limited cricket numers. The contents of ech continer were sifted dily to evlute mortlity for 3 weeks fter initil cricket plcement (18 Aug Sep 2009, 23 Aug Sep 2009, nd 11 Aug Sep 2009). Evlution 1 pertins to mortlity recorded 1 DAE nd evlution 2 pertins to mortlity recorded 5 DAE. Behvior Study I: No-Choice Test Mole cricket ehviorl responses to selected insecticides were monitored in 68-liter storge oxes ( cm, Ruermid Inc., Atlnt, Georgi) in 2008 nd 15-liter storge oxes ( cm, Sterilite Corp., Townsend, Msschusetts) in Dringe holes drilled into the ottom of ech storge ox reduced excess moisture. Fierglss screen (Phifer Inc., Tuscloos, Alm) ws secured to the ottom of the storge ox with glue to prevent mole cricket escpe. In 2008, the 68 liter storge oxes were filled to depth of 30.5 cm with ntive soil (Norfolk, fine sndy lom deep phse, HM = 0.66%, ph = 4.1, CEC = 3.2) from the Olde Fort Golf Course mole cricket collection site. In 2009, the 15-liter storge oxes were filled to depth of 12.7 cm with soil from the sme loction. In 2008, soil ws treted on 23 Oct (0 d), 19 Sep (30 d), nd 19 Aug (60 d), prior to cricket plcement nd in 2009, tretments were mde on 11 Sep (0 d), 7 Aug (30 d), 8 Jul (60 d), nd 9 Jun (90 d). The queous preprtion of chlorntrniliprole ws pplied using Delt Oritl 360 Spryer (Delt Industries, King of Prussi, Pennsylvni) delivering pproximtely 708 liters/h in 2008 nd 795 liters/h in The spry volume ws different due to the chnge in continer size. In 2008, there were no control tretments for the 30 nd 60 d pplictions. Storge oxes plced outdoors were exposed to mient tempertures, rinfll, nd sunlight to llow for typicl pesticide degrdtion on re soil. In 2008, the monthly verge tempertures for the durtion of this experiment were s follows: Aug: C, Sep: C, nd Oct: C. The monthly totl rinfll for the durtion of this experiment ws s follows: Aug: 8.48 cm, Sep: cm, nd Oct: 3.45 cm. In 2009, the Sep verge temperture ws C nd the totl rinfll ws 8.25 cm. To mintin reltively stle mient conditions ( C) during the evlution period storge oxes were rought into the greenhouse efore cricket plcement in 2008, nd shde cloth (PC Pools, St. Pul, MN) ws plced over the storge oxes during the evlution period in In 2008, the experiments were conducted lter in the fll (Oct- Nov) thn in 2009, so the tus were rought into the greenhouse to reduce mole cricket exposure to cold tempertures. In 2009, experiments were conducted erlier in the fll (Sep), so the tus remined outside; shde cloth, llowing 50% of sunlight trnsmission, ws plced over top of the continers to reduce mole cricket exposure to high tempertures. A single lrge nymph or dult twny mole cricket ( cm) collected on 21 Oct 2008 or on 10 Sep 2009 ws plced in the center of ech storge ox t the onset of the evlution period. A lid ws plced over the top of the storge ox to prevent cricket escpe. In 2008, the center of ech 68 liter storge ox lid ws removed, leving 2.54 cm order, nd fierglss screen (Phifer Inc., Tuscloos, Alm) ws secured to the order with glue. In 2009 ten dringe holes were drilled into ech 15 liter storge ox lid to llow wter ccumulted on the top to drin. A grid system similr to tht used y Co & Mck (1989) ws used to ssess surfce tunneling in the storges oxes over oth yers. In 2008, cm cm grid ws mde using metl r s the frme nd monofilment fishing line ttched to the frme to crete the 54 internl grid squres. In 2009, cm cm grid ws mde using lid from one of the 15 liter storge oxes nd Lehigh #18 gold mson line (The Lehigh Group, Mcungie, PA) to crete the 35 internl grid squres. The chnge to gold string in 2009 mde the grid esier

5 66 Florid Entomologist (95)1 Mrch 2012 to see when ginst the soil ckground. In oth yers the grid ws plced over the top of the storge ox, ut not touching the soil nd the numer of squres tht contined mole cricket surfce tunneling ws counted. The numer of squres tht contined evidence of tunneling ws divided y the totl numer of grid squres to determine the percent tunneling for ech storge ox. Rtings were tken t 5, 11, nd 15 d (referred to herefter s evlution 1, 2, nd 3 respectively) fter cricket plcement in 2008 nd 1, 3, nd 7 d (referred to herefter s evlution 1, 2, nd 3 respectively) fter cricket plcement in Behvior Study II: Choice Test Behvior study II used the sme continers nd sme preprtion methods s ehvior study I. Ech storge ox ws mrked long the top edge long the long dimension to define the hlfwy point. A field stke ws plced on top of the soil to demrcte ech hlf nd prevent overspry of untreted side. One hlf of the soil in ech ox ws then treted with the pproprite insecticide, while the other side remined untreted. There ws no physicl rrier etween the treted nd untreted soil for the durtion of the experiment. The hnd-held spryer produced course droplets, thus eliminting the concern of pesticide drift. Cre ws tken to ensure the soil surfce ws level efore ppliction so wter infiltrtion would e downwrds nd not contminte the untreted soil. The oxes were rotted so tht the orienttion of the treted nd untreted sides in the oxes within replicte ws rndomized. In 2008, soil ws treted on 13 Nov (0 d), 3 Oct (30 d), nd 30 Aug or 2 Sep (60 d) dys prior to cricket plcement nd in 2009 tretments were mde on 27 Sep (0 d), 17 Aug (30 d), 15 Jul (60 d), nd 15 Jun (90 d). Insecticides were pplied to the treted hlves using the sme techniques t the stndrd rtes previously listed. Storge oxes were plced outdoors nd exposed to mient tempertures, rinfll, nd sunlight, to llow for typicl pesticide degrdtion on re soil. To mintin reltively stle mient conditions ( C) during the evlution period, storge oxes were rought into the greenhouse efore cricket plcement (in 2008), or shde cloth (PC Pools, St. Pul, MN) ws plced over the storge oxes during the evlution period (in 2009), s previously descried. A single lrge nymph or dult twny mole cricket ( cm) collected in 2008 on 21 Oct, 6 Nov, or in 2009 on 24 Sep, or 6 Oct ws plced on the soil t the order etween treted nd untreted sides of ech continer t the onset of the evlution period. The 60 d chlorntrniliprole treted tus in 2008 hd crickets plced on soil nd dt collected 22 d prior to the rest of the tus due to limited cricket numers. A lid ws plced over the top of the storge ox to prevent cricket escpe s previously descried. Tunneling rtings were tken using the sme grids used in previous experiment, except tht in this study, seprte tunnel rting ws tken for the treted nd untreted hlves of ech ox. The grid ws plced on top of the storge ox, ut not touching the soil, nd the sme mrk used to divide the storge ox in hlf during tretment ws used to determine the middle of the grid. The numer of squres tht hd surfce tunneling in them ws counted seprtely for ech side. The numer of squres tht hd tunneling in them ws divided y the totl numer of grid squres for tht side to determine the percent tunneling for ech side of ech storge ox. Rtings were tken t 7, 13, nd 20 d for the 60 d chlorntrniliprole tus in 2008, 5, 11, nd 28 d for the rest of the tus in 2008 [referred to herein s evlution 1 (d 7 nd 5 respectively fter cricket plcement) evlution 2 (d 13 nd 11 respectively fter cricket plcement) nd evlution 3 (d 20 nd 28 respectively fter cricket plcement)] nd 1, 3, nd 7 d (referred to herefter s evlution 1, 2, nd 3 respectively) intervls fter cricket plcement in Insecticide iossy dt (% mortlity) were trnsformed (inry) prior to nlysis for insecticide nd residue effect using Proc LOGISTIC. Dt were nlyzed through use of Sttisticl Anlysis System version 9.1 progrm (SAS Institute 2003). No-choice ehvior dt were nlyzed for insecticide nd residue effect using Proc GLIMMIX nd djusted using Bonferroni correction for multiple comprisons. Dt were nlyzed through use of Sttisticl Anlysis System version 9.2 progrm (SAS Institute 2008). Choicetest ehvior dt were trnsformed (rcsine) prior to nlysis for insecticide nd residue effect using Proc MIXED. Dt were nlyzed through use of Sttisticl Anlysis System version 9.1 progrm (SAS Institute 2003). For ll nlyses of vrince, = RESULTS Insecticide Biossy I: Smll Nymphs There were significnt differences in mortlity mong tretments for the 0 d residues t the stndrd nd high rtes t oth evlutions (Tles 1 nd 2). There were significnt differences in mortlity mong tretments for the 30 d residues t the stndrd rte on evlution 2 nd the high rte on evlutions 1 nd 2 (Tles 1 nd 2). There were significnt differences in mortlity mong tretments for the 60 d residues t the stndrd nd high rtes on evlution 2 (Tles 1 nd 2). There were significnt differences in mortlity mong tretments for the 90 d residues t the stndrd rte on oth evlutions nd t

6 Silcox et l.: Mole Cricket Avoidnce Behvior to Synthetic Insecticides 67 TABLE 1. AVERAGE PERCENT MORTALITY OF SMALL NYMPHS ON EVALUATION 1 AND 2 TO TUBS TREATED WITH 3 INSETCICIDES AT THE STANDARD RATE A FOR APPLICATIONS MADE 0, 30, 60, AND 90 D PRIOR TO CRICKET INTRODUCTION B. % Mortlity Evlution 1 Evlution 2 0 d 30 d 60 d 90 d 0 d 30 d 60 d 90 d Untreted Bifenthrin Chlorntrniliprole Fipronil P < Rtes: ifenthrin = kg i/h; chlorntrniliprole = kg i/h; fipronil = kg i/h. Dt were trnsformed (inry) prior to nlysis for tretment effect using Proc LOGISTIC, in ll cses df = 3. TABLE 2. AVERAGE PERCENT MORTALITY OF SMALL NYMPHS ON EVALUATION 1 AND 2 TO TUBS TREATED WITH 3 INSECTICIDES AT HIGH RATE A FOR APPLICATIONS MADE 0, 30, 60, AND 90 D PRIOR TO CRICKET INTRODUCTION B. % Mortlity Evlution 1 Evlution 2 0 d 30 d 60 d 90 d 0 d 30 d 60 d 90 d Untreted Bifenthrin Chlorntrniliprole Fipronil P < < < Rtes: ifenthrin = kg i/h; chlorntrniliprole = kg i/h; fipronil = kg i/h Dt were trnsformed (inry) prior to nlysis for tretment effect using Proc LOGISTIC, in ll cses df = 3. the high rte on evlution 2 (Tles 1 nd 2). There were no significnt differences in mortlity mong tretments for the 30 nd 60 d residues, t stndrd rte on evlution 1 (Tle 1) nd for the 60 nd 90 d residues, t stndrd rte on evlution 1 (Tle 2). Insecticide Biossy II: Lrge Nymphs There were significnt differences in mortlity mong tretments for the 0 d residues t the stndrd nd high rtes t oth evlutions (Tles 3 nd 4). There were significnt differences in mortlity mong tretments for the 30 d residues t the stndrd nd high rtes on evlution 2 (Tles 3 nd 4). There ws no nlysis run for the 30 d residues t the stndrd or high rte t evlution 1 s there ws no cricket mortlity in ny tretment (Tles 3 nd 4). There were significnt differences in mortlity mong tretments for the 60 d residues t the high rte on evlution 2 (Tle 4). There were no significnt differences in mortlity mong tretments for the 90 d residues t either rte on oth evlution d (Tle 3 nd 4). There ws no nlysis run for the 90 d residues t the stndrd or high rtes on evlution 1 s there ws no cricket mortlity in ny tretment (Tle 3 nd 4). There were no significnt differences in mortlity mong tretments for the 60 d residues t the stndrd rte on oth evlution d (Tle 3) nd for the 60 d residues t the high rte on evlution 1 (Tle 4). Behvior Study I: No-Choice Test There were significnt differences in the mount of surfce tunneling etween tretments for the 0, 30, nd 60 d residue t ll evlutions for the 2008 storge oxes-entire surfce treted ehvior study (Tle 5). Results from the no-choice ehvior study in 2008 indicte tht for ll 0 d residue tretments there ws significnt difference in the mount of surfce tunneling etween the untreted control nd the 3 insecticide tretments on ll evlutions (Tle 6). For ll residue tretments there ws lso significnt difference in the mount of surfce tunneling etween the ifenthrin nd chlorntrniliprole tretments s well s mrginlly significnt etween the chlorntrniliprole nd fipronil tretments on ll

7 68 Florid Entomologist (95)1 Mrch 2012 TABLE 3. AVERAGE PERCENT MORTALITY OF LARGE NYMPHS ON EVALUATION 1 AND 2 TO TUBS TREATED WITH 3 INSECTICIDES AT THE STANDARD RATE A FOR APPLICATIONS MADE 0, 30, 60, AND 90 D PRIOR TO CRICKET INTRODUCTION B. % Mortlity Evlution 1 Evlution 2 0 d 30 d 60 d 90 d 0 d 30 d 60 d 90 d Untreted Bifenthrin Chlorntrniliprole Fipronil NA c 2.99 NA c P NA NA < < Rtes: ifenthrin = kg i/h; chlorntrniliprole = kg i/h; fipronil = kg i/h. Dt were trnsformed (inry) prior to nlysis for tretment effect using Proc LOGISTIC, in ll cses df = 3. c Comprisons not mde due to 100% mole cricket survivl mong tretments. TABLE 4. AVERAGE PERCENT MORTALITY OF LARGE NYMPHS ON EVALUATION 1 AND 2 TO TUBS TREATED WITH 3 INSECTICIDES AT THE HIGH RATE A FOR APPLICATIONS MADE 0, 30, 60, AND 90 D PRIOR TO CRICKET INTRODUCTION B. % Mortlity Evlution 1 Evlution 2 0 d 30 d 60 d 90 d 0 d 30 d 60 d 90 d Untreted Bifenthrin Chlorntrniliprole Fipronil NA c 5.17 NA c P NA NA Rtes: ifenthrin = kg i/h; chlorntrniliprole = kg i/h; fipronil = kg i/h. Dt were trnsformed (inry) prior to nlysis for tretment effect using Proc LOGISTIC, in ll cses df = 3. c Comprisons not mde due to 100% mole cricket survivl mong tretments. TABLE 5. AVERAGE PERCENT SURFACE TUNNELING OF MOLE CRICKETS ON EVALUATION 1, 2, AND 3 OF NO-CHOICE TESTS WITH 3 INSECTICIDES AT STANDARD RATE FOR APPLICATIONS MADE 0, 30, AND 60 D PRIOR TO CRICKET INTRODUCTION IN 2008 A Averge Surfce Tunneling Evlution 1 Evlution 2 Evlution 3 0 d 30 d 60 d 0 d 30 d 60 d 0 d 30 d 60 d Untreted 0.51 NA NA 0.55 NA NA 0.61 NA NA Bifenthrin Chlorntrniliprole Fipronil F df P < < < < < < Dt were nlyzed for tretment effect using Proc GLIMMIX. Dt not ville due to lck of control tretments for 30 nd 60 d pplictions.

8 Silcox et l.: Mole Cricket Avoidnce Behvior to Synthetic Insecticides 69 TABLE 6. NO-CHOICE TESTS PAIR-WISE COMPARISONS OF THE AVERAGE PERCENT SURFACE TUNNELING OF MOLE CRICKETS ON EVALUATION 1, 2, AND 3 ON TUBS TREATED WITH 3 INSECTICIDES FOR APPLICATIONS MADE 0, 30, AND 60 D PRIOR TO CRICKET INTRODUC- TION IN 2008 A P vlue Evlution 1 Evlution 2 Evlution 3 0 d 30 d 60 d 0 d 30 d 60 d 0 d 30 d 60 d Unt vs Bifenthrin < NA c NA < NA NA < NA NA Unt vs Chlorntrniliprole NA NA NA NA NA NA Unt vs Fipronil < NA NA < NA NA < NA NA Bifenthrin vs Chlorntrniliprole < < < Bifenthrin vs Fipronil Chlorntrniliprole vs Fipronil Dt were nlyzed using Proc GLIMMIX; in ll cses df = 30. P vlues were djusted with Bonferroni correction. c Dt not ville due to lck of control tretments for 30 nd 60 d pplictions. evlutions (Tle 6). For ll residue tretments there ws no significnt difference etween the mount of surfce tunneling etween the ifenthrin nd fipronil tretments on ll evlutions (Tle 6). In the 2009 no-choice ehvior study, there were significnt differences in the mount of surfce tunneling etween tretments for the 0, 30, 60, nd 90 d residues t ll evlutions (Tle 7). Results from the no-choice ehvior study in 2009 were not consistent with the results seen in 2008 in the mount of surfce tunneling etween the untreted control nd the 3 insecticide tretments (Tle 8). Chlorntrniliprole hd the gretest numer (10) of significnt differences in mount of surfce tunneling compred to the mount of surfce tunneling for the untreted controls (Tle 8). There ws lso vriility in the mount of surfce tunneling etween the 3 insecticides when compred to ech other (Tle 8). Bifenthrin nd chlorntrniliprole tretments hd the gretest numer (10) of significnt differences in the mount of surfce tunneling etween the two tretments. Chlorntrniliprole nd fipronil tretments hd the second gretest numer of differences etween the 2 tretments. Behvior Study II: Choice Test In the 2008 choice test ehvior study there ws no significnt difference in the mount of surfce tunneling etween the treted nd untreted sides of the insecticide treted tus (F = 1.71, df = 1, P = ), etween insecticide tretments (F = 0.81, df = 2, P = ), or etween residue (0, 30, 60, 90 d) tretments (F = 0.50, df = 2, P = for evlution 1 (Tle 9). There ws no significnt difference in the mount of surfce tunneling etween the treted nd untreted sides of the insecticide treted tus (F = 0.00, df = 1, P = ), etween insecticide tretments (F = 1.19, df = 2, P = ), or etween residue tretments (F = 1.59, df = 2, P = for evlution 2 (Tle 10). There ws no significnt difference in the mount of surfce tunneling etween the treted nd untreted sides of the insecticide treted tus (F = 0.00, df = 1, P = ), etween insecticide tretments (F = 1.82, df = 2, P = ), or etween residue tretments (F = 2.16, df = 2, P = ) for evlution 3 (Tle 11). Overll the choice test ehvior study in 2008 indicted ifenthrin nd fipronil hd the numericlly lowest verge surfce tunneling grid rtings compred to the verge tunneling on the untreted side (Tles 9-11). The chlorntrniliprole treted soil hd the numericlly highest verge surfce tunneling grid rtings compred to the verge tunneling on the untreted side (Tles 9+11). The control storge oxes, in which neither hlf ws treted, hd numericlly moderte surfce tunneling compred to the verge tunneling on

9 70 Florid Entomologist (95)1 Mrch 2012 TABLE 7. AVERAGE PERCENT SURFACE TUNNELING OF MOLE CRICKETS ON EVALUATION 1, 2, AND 3 ON NO-CHOICE TESTS WITH 3 INSECTICIDES AT STANDARD RATE FOR APPLICATIONS MADE 0, 30, 60, AND 90 D PRIOR TO CRICKET INTRODUCTION IN 2009 A. Averge Surfce Tunneling Evlution 1 Evlution 2 Evlution 3 0 d 30 d 60 d 90 d 0 d 30 d 60 d 90 d 0 d 30 d 60 d 90 d Untreted Bifenthrin Chlorntrniliprole Fipronil F P < < < < < < < < < Dt were nlyzed for tretment effect using Proc GLIMMIX, in ll cses df = 3. TABLE 8. NO-CHOICE TESTS PAIR-WISE COMPARISONS OF THE AVERAGE SURFACE TUNNELING OF MOLE CRICKETS ON EVALUATION 1, 2, AND 3 ON TUBS TREATED WITH 3 INSECTICIDES FOR AP- PLICATIONS MADE 0, 30, 60, AND 90 D PRIOR TO CRICKET INTRODUCTION IN 2009 A. P vlue P vlue Evlution 1 Evlution 2 Evlution 3 0 d 30 d 60 d 90 d 0 d 30 d 60 d 90 d 0 d 30 d 60 d 90 d Unt vs Bifenthrin < < < Unt vs Chlorntrniliprole < < < < < Unt vs Fipronil < < Bifenthrin vs Chlorntrniliprole < < < < < < < Bifenthrin vs Fipronil < Chlorntrniliprole vs Fipronil < < < < < Dt were nlyzed using Proc GLIMMIX, in ll cses df = 80. P vlues were djusted with Bonferroni correction.

10 Silcox et l.: Mole Cricket Avoidnce Behvior to Synthetic Insecticides 71 the untreted sides of the hlf insecticide treted storge oxes (Tles 9-11). In the 2009, choice test ehvior study there ws significnt difference in the mount of surfce tunneling etween the treted sides nd untreted side of the insecticides treted tus (F = 20.91, df = 1, P <0.0001), ut the tretment effect did not vry etween insecticides (F = 0.21, df = 2, P = ) for evlution 1 (Tle 12). There ws significnt difference in the mount of surfce tunneling etween residue tretments (F = 3.03, df = 3, P = ) for evlution 1 (Tle 12). There ws significnt difference in the mount of surfce tunneling etween the treted nd untreted sides of the insecticide treted tus (F = 21.40, df = 1, P <0.0001), ut the tretment effect did not vry etween insecticides (F = 0.43, df = 2, P = ) for evlu- TABLE 9. AVERAGE SURFACE TUNNELING OF MOLE CRICKETS ON EVALUATION 1 OF CHOICE TESTS TREATED WITH 3 INSECTICIDES AT STANDARD RATE OF APPLICATIONS MADE, 0, 30, AND 60 DAYS PRIOR TO CRICKET INTRODUCTION IN 2008 A Averge % Surfce Tunneling 0 d 30 d 60 d s Treted Untreted Treted Untreted Treted Untreted Untreted N/A N/A N/A N/A N/A Bifenthrin Chlorntrniliprole Fipronil Dt trnsformed (log) prior to nlysis for tretment effect using Proc MIXED. Dt not ville due to lck of control tretments for 30 nd 60 dy pplictions nd the treted sides. TABLE 10. AVERAGE SURFACE TUNNELING OF MOLE CRICKETS ON EVALUATION 2 OF CHOICE TESTS TREATED WITH 3 INSECTICIDES AT STANDARD RATE OF APPLICATIONS MADE, 0, 30, AND 60 D PRIOR TO CRICKET INTRODUCTION IN 2008 A. Averge % Surfce Tunneling 0 d 30 d 60 d s Treted Untreted Treted Untreted Treted Untreted Untreted N/A N/A N/A N/A N/A Bifenthrin Chlorntrniliprole Fipronil Dt trnsformed (log) prior to nlysis for tretment effect using Proc MIXED. Dt not ville due to lck of control tretments for 30 nd 60 d pplictions nd the treted sides. TABLE 11. AVERAGE SURFACE TUNNELING OF MOLE CRICKETS ON EVALUATION 3 OF CHOICE TESTS TREATED WITH 3 INSECTICIDES AT STANDARD RATE OF APPLICATIONS MADE, 0, 30, AND 60 D PRIOR TO CRICKET INTRODUCTION IN 2008 A. Averge % Surfce Tunneling 0 d 30 d 60 d s Treted Untreted Treted Untreted Treted Untreted Untreted N/A N/A N/A N/A N/A Bifenthrin Chlorntrniliprole Fipronil Dt trnsformed (log) prior to nlysis for tretment effect using Proc MIXED. Dt not ville due to lck of control tretments for 30 nd 60 d pplictions nd the treted sides.

11 72 Florid Entomologist (95)1 Mrch 2012 TABLE 12. AVERAGE SURFACE TUNNELING OF MOLE CRICKETS ON EVALUATION 1 OF CHOICE TESTS TREATED WITH 3 INSECTICIDES AT STANDARD RATE OF APPLICATIONS MADE, 0, 30, 60, AND 90 DAYS PRIOR TO CRICKET INTRODUCTION IN 2009 A. Averge % Surfce Tunneling 0 d 30 d 60 d 90 D s Treted Untreted Treted Untreted Treted Untreted Treted Untreted Untreted N/A N/A N/A N/A Bifenthrin Chlorntrniliprole Fipronil Dt trnsformed (log) prior to nlysis for tretment effect using Proc MIXED. Dt not ville due to lck of control tretments for the treted sides. TABLE 13. AVERAGE SURFACE TUNNELING OF MOLE CRICKETS ON EVALUATION 2 OF CHOICE TESTS TREATED WITH 3 INSECTICIDES AT STANDARD RATE OF APPLICATIONS MADE, 0, 30, 60, AND 90 D PRIOR TO CRICKET INTRODUCTION IN 2009 A. Averge % Surfce Tunneling 0 d 30 d 60 d 90 D s Treted Untreted Treted Untreted Treted Untreted Treted Untreted Untreted N/A N/A N/A N/A Bifenthrin Chlorntrniliprole Fipronil Dt trnsformed (log) prior to nlysis for tretment effect using Proc MIXED. Dt not ville due to lck of control tretments for the treted sides. tion 2 (Tle 13). There ws no significnt difference in the mount of surfce tunneling etween residue tretments (F = 2.44, df = 3, P = ) for evlution 2 (Tle 13). There ws significnt difference in the mount of surfce tunneling etween the treted nd untreted sides of the insecticide treted tus (F = 10.26, df = 1, P = ), ut the tretment effect did not vry etween insecticides (F = 0.22, df = 2, P = ) for evlution 3 (Tle 14). There ws significnt difference in the mount of surfce tunneling etween residue tretments (F = 3.00, df = 3, P = ) for evlution 3 (Tle 14). Results from the choice test ehvior study in 2009 indicte the treted sides hd n overll numericlly lower verge surfce tunneling grid rtings compred to the verge tunneling on the untreted side (Tles 12-14). Bifenthrin-treted soil hd the numericlly lowest overll verge surfce tunneling grid rtings compred to the verge tunneling on the untreted side (Tles 12-14). The fipronil-treted nd chlorntrniliprole-treted sides hd vrition etween which hlves (treted or untreted); the lower mount of surfce tunneling ws oserved in the fipronil nd chlorntrniliprole tretments (Tles 12-14). DISCUSSION Across ll 4 iossys, ifenthrin nd fipronil hd lrger effect on mortlity compred to chlorntrniliprole nd the control. This is consistent with the reltive mortlity to mole crickets of these 3 insecticides oserved in other studies (Potter 1998; Brndenurg et l. 2004). In generl, ifenthrin tretments hd higher mortlity for the first evlution thn fipronil. This is expected; fipronil nd its metolites re slower cting thn ifenthrin (Brndenurg t l. 2004). The low mortlity seen in the chlorntrniliprole tretments reflects the pprent low toxicity of the compound ginst mole crickets (RLB unpulished dt). The results seen in the 2008 no-choice studies re consistent with the morlity results of the iossys. The ifenthrin nd fipronil tretments hd the highest efficcy ginst mole crickets nd reduced surfce tunneling y the mole crickets to greter extent thn chlorntrniliprole. The chlorntrniliprole hd the lowest efficcy ginst mole crickets nd hd little impct on reducing surfce tunneling. In 2009, the trends were similr, ut there ws greter vriility mong tretments tht hd lower surfce tunnel-

12 Silcox et l.: Mole Cricket Avoidnce Behvior to Synthetic Insecticides 73 TABLE 14. AVERAGE SURFACE TUNNELING OF MOLE CRICKETS ON EVALUATION 3 OF CHOICE TESTS TREATED WITH 3 INSECTICIDES AT STANDARD RATE OF APPLICATIONS MADE, 0, 30, 60, AND 90 D PRIOR TO CRICKET INTRODUCTION IN 2009 A. Averge % Surfce Tunneling 0 d 30 d 60 d 90 d s Treted Untreted Treted Untreted Treted Untreted Treted Untreted Untreted N/A N/A N/A N/A Bifenthrin Chlorntrniliprole Fipronil Dt trnsformed (log) prior to nlysis for tretment effect using Proc MIXED. Dt not ville due to lck of control tretments for the treted side. ing. This could e prtly due to the chnge in the size of the tu. The smller tus in 2009 could hve incresed the concentrtion of the voltiles or other residues from the insecticides the crickets cme in contct with. Bifenthrin is more voltile thn fipronil, which is more voltile thn chlorntrniliprole (Fecko 1999; Connelly 2001; Austrlin Pesticides nd Veterinry Medicines Authority 2008). The differences in voltility my help explin the ehviorl chnges rther thn mortlity lone. The mole crickets could hve een trying to escpe the tretment, ut in smller continer this my hve ctully incresed surfce tunneling. In previous reserch, the ehviorl response of mole crickets ws influenced y the inherent mortlity cused y the product; the more effective (toxic) the product, the greter the impct on mole cricket voidnce ehvior (Thompson & Brndenurg 2005 nd Thompson et l. 2007). The differences in mode of ction of ech insecticide could lso explin the ehviorl chnges rther thn mortlity lone. Bifenthrin nd fipronil primrily work through contct with the insect, while chlorntrniliprole primrily works through ingestion y the insect. Pyrethroids (ifenthrin in this study) re known to cuse repellency in other rthropods (Desneux et l. 2007). Our results confirm the findings of previous studies (Villni et l. 2002; Thompson & Brndenurg 2005) using entomopthogenic fungi nd ifenthrin. The results of the choice studies were in generl similr to the results of the no-choice continers. There ws less sttisticl significnce in the choice tests; however, in the mjority of the ssys, the verge surfce tunneling for the ifenthrin-treted sides ws lower thn the verge surfce tunneling for the untreted sides. The verge mount of surfce tunneling on the chlorntrniliprole nd fipronil treted sides vried from lower to higher compred to the untreted sides mong residue tretments. The reltively low verge percent surfce tunneling seen in the chlorntrniliprole treted sides versus untreted sides could e relted to the vrile mortlity seen in the iossys. Chlorntrniliprole cused miniml mole cricket mortlity, so they did not void the tretment, ut some susequently died from nturl cuses. The vriility in the fipronil-treted sides could e relted to the high mortlity of fipronil for the 0 dy residue in the iossys, ut the lower mortlity of fipronil for the 30, 60, nd 90 dy residues in the iossys. The mole crickets could hve tried to escpe the toxic tretment, ut the smll continer resulted in tunneling in the treted side. In oth ehvior studies, mortlity ws only recorded if the cricket ws on the soil surfce ded. Mortlity elow the soil surfce during the course of the ssy could not e mesured with this study design. As result, percent surfce tunneling ws recorded for every tu on ll evlutions. Soil nlysis (Silcox 2011) ws conducted y privte lortories which confirmed tht the insecticides were reking down s expected on re soil nd insecticide residues were detected. This study llowed us to ssocite mortlity cused y n insecticide, with surfce tunneling oserved in ehviorl experiments. If tretment produced high mortlity in the iossy we would expect reduced surfce tunneling in the continers with similr treted soils due to mole cricket voidnce nd/or mortlity. However, in the cse of the no-choice tests they could not tunnel t the surfce without exposure to the insecticide. It ws difficult to seprte out whether the reduced surfce tunneling recorded ws due to mortlity or voidnce of tht treted re. The reduction of surfce tunneling ws seen immeditely in ifenthrin nd fipronil tretments in the no-choice experiments; however the mortlity recorded in the iossys did not occur s quickly. The choice tests provided n opportunity for the crickets to tunnel t the surfce while voiding treted soil. The reduced surfce tunneling seen on the treted sides of tus versus the untreted sides, lthough not significnt, provides insight

13 74 Florid Entomologist (95)1 Mrch 2012 into voidnce to treted tus s compred to untreted tus. In generl, we found tht the greter the mortlity of the insecticide the greter the reduction of surfce tunneling. These studies confirm previous mngement recommendtions tht timing of insecticides is very importnt in chieving effective control of mole crickets (Potter 1998; Brndenurg et l. 2004) nd confirmed reported voidnce oserved in previous studies (Villni et l. 2002; Thompson et l. 2007). Insecticides should e pplied when the nymphs re smll (less thn 1.27 cm) to minimize the consequences of ehviorl responses of lrge nymphs (greter thn 2.54 cm). Lrge nymphs re le to tunnel s fr s 70 cm in the ground (Brndenurg et l. 2002) nd would e le to modify their ehvior in such wy tht the control mesure could not e effective. This requires monitoring the infested res for surfce tunneling s well s sopy wter flushing to determine egg htch nd nymph size. Proper timing, complete coverge nd pproprite rtes of the insecticides re the keys for mximizing effectiveness (Xi nd Brndenurg 2000). REFERENCES CITED AUSTRALIAN PESTICIDES AND VETERINARY MEDICINES AU- THORITY Evlution of new ctive chlorntrniliprole in the products DuPont corgen insecticide, DuPont ltcor insecticide, nd DuPont Acelepryn insecticide. Cnerr, Austrli. BRANDENBURG, R.L Mnging mole crickets: developing strtegy for success. Turfgrss Trends 6(1): 1-8. BRANDENBURG, R. L., HERTL, P. T., AND VILLANI, M. G Improved mole cricket mngement through n enhnced understnding of pest ehvior. Am. Chem. Soc. 743: BRANDENBURG, R. L., XIA, Y., AND SCHOEMAN, A. S Tunnel rchitectures of three species of mole crickets (Orthopter: Gryllotlpide). Florid Entomol. 85(2): BRANDENBURG, R. L., XIA, Y., AND WATSON, B Comprtive toxicity nd efficcy of selected insecticides in field nd greenhouse ssys ginst twny nd southern mole crickets (Orthopter: Gryllotlpide). J. Entomol. Sci. 40(2): ). COBB, P.P., AND MACK, T.P A rting system for evluting twny mole cricket, Scpteriscus vicinus Scudder, dmge (Orthopter: Gryllotlpide). J. Entomol. Sci. 24(1): ). CONNELLY,P Environmentl fte of fipronil. Environ. Monitoring Brnch, Dept. Pesticide Reg., Cliforni Environ. Prot. Agency, Scrmento, Cliforni. CUMMINGS, H. D., BRANDENBURG, R. L., LEIDY, R. B., AND YELVERTON, F.H Impct of Fipronil residues on mole cricket (Orthopter: Gryllotlpide) ehvior nd mortlity in ermudgrss. Florid Entomol. 89(3): DESNEUX, N., DECOURTYE, A., AND DELPUECH, J. M The sulethl effects of pesticides on eneficil rthropods. Annu. Rev. Entomol. 52(81): FECKO, A Environmentl fte of ifenthrin. Environ. Monitoring nd Pest Mng. Brnch, Dept. Pesticide Reg., Scrmento, Cliforni. POTTER, D. A Destructive turfgrss insects. Ann Aror Press, Chelse, Michign. SAS INSTITUTE PROC user s mnul, version 9.1 SAS Institute, Cry, North Crolin. SAS INSTITUTE PROC user s mnul, version 9.2 SAS Institute, Cry, North Crolin. SHORT, D. E., AND KOEHLER, P. G A smpling technique for mole crickets nd other pests in turfgrss nd psture. Florid Entomol. 62: SILCOX, D. E Response of the twny mole cricket (Orthopter: Gryllotlpide) to synthetic insecticides nd their residues. M.S. Thesis. North Crolin Stte Univ., Rleigh, North Crolin. THOMPSON, S. R., AND BRANDENBURG, R. L Tunneling responses of mole crickets (Orthopter: Gryllotlpide) to the entomopthogenic fungus, Beuveri ssin. Environ. Enomol. 34(1): THOMPSON, S. R., BRANDENBURG, R. L., AND ROBERSON, G. T Entomopthogenic fungi detection nd voidnce y mole crickets (Orthopter: Gryllotlpide). Environ. Entomol. 36(1): VILLANI, M. G., ALLEE, L. L., PRESTON-WILSEY, L., CONSO- LIE, N., XIA, Y., AND BRANDENBURG, R.L Use of rdiogrphy nd tunnel cstings for oserving mole cricket (Orthopter: Gryllotlpide) ehvior in soil. Am. Entomol. 48(1): XIA, Y., AND BRANDENBURG, R.L Tret young mole crickets for relile insecticide results. Golf Course Mng. 68(3):