2001 RUTGERS Turfgrass Proceedings

Transcription

1 200 RUTGERS Turfgrass Procdings Rutgrs Univrsity THE NEW JERSEY TURFGRASS ASSOCIATION In Coopration With RUTGERS COOPERATIVE EXTENSION NEW JERSEY AGRICULTURAL EXPERIMENT STATION RUTGERS, THE STATE UNIVERSITY OF NEW JERSEY NEW BRUNSWICK Distributd in coopration with U.S. Dpartmnt of Agricultur in furthranc of th Acts of Congrss of May 8 and Jun 30, 94. Cooprativ Extnsion work in agricultur, hom conomics, and 4-H. Zan R. Hlsl, Dirctor of Extnsion. Rutgrs Cooprativ Extnsion provids information and ducational srvics to all popl without rgard to sx, rac, color, national origin, disability or handicap, or ag. Rutgrs Cooprativ Extnsion is an Equal Opportunity Employr.

2 200 RUTGERS TURFGRASS PROCEEDINGS of th Nw Jrsy Turfgrass Expo Dcmbr -3, 200 Trump Taj Mahal Atlantic City, Nw Jrsy Th Rutgrs Turfgrass Procdings is publishd yarly by th Rutgrs Cntr for Turfgrass Scinc, Rutgrs Cooprativ Extnsion, and th Nw Jrsy Agricultural Exprimnt Station, Cook Collg, Rutgrs, Th Stat Univrsity of Nw Jrsy in coopration with th Nw Jrsy Turfgrass Association. Th purpos of this documnt is to provid a forum for th dissmination of information and th xchang of idas and knowldg. Th procdings provid turfgrass managrs, rsarch scintists, xtnsion spcialists, and industry prsonnl with opportunitis to communicat with co-workrs. Through this forum, ths profssionals also rach a mor gnral audinc, which includs th public. This publication includs lctur nots of paprs prsntd at th 200 Nw Jrsy Turfgrass Expo. Publication of ths lcturs provids a radily availabl sourc of information covring a wid rang of topics and includs tchnical and popular prsntations of importanc to th turfgrass industry. This procdings also includs rsarch paprs that contain original rsarch findings and rviws of slctd subjcts in turfgrass scinc. Ths paprs ar prsntd primarily to facilitat th timly dissmination of original turfgrass rsarch for us by th turfgrass industry. Spcial thanks ar givn to thos who hav submittd paprs for this procdings, to th Nw Jrsy Turfgrass Association for financial assistanc, and to thos individuals who hav providd support to th Rutgrs Turfgrass Rsarch Program at Cook Collg, Rutgrs, Th Stat Univrsity of Nw Jrsy. Dr. Ann Brooks Gould, Editor Dr. Bruc B. Clark, Coordinator 200 Rutgrs Turfgrass Procdings

3 TURFGRASS INSECT CONTROL: CHOICES AND TIMING FOR LAWN AND LANDSCAPE TURF Albrcht M. Koppnhöfr WHITE GRUBS Whit grubs, th root-fding larva of scarab btls, ar important psts of turfgrass, pasturs, and many crops throughout th world. At last 0 spcis caus significant damag to turfgrasss in th Unitd Stats. In th northastrn Unitd Stats, a complx of primarily introducd whit grub spcis compriss th major turfgrass insct psts. Among ths, th Japans btl, Popillia japonica, has until rcntly bn rgardd as th ky spcis, but othr whit grub spcis ar bcoming mor important. Ths othr spcis includ th orintal btl (Exomala (=Anomala) orintalis), th Europan chafr (Rhizotrogus majalis), and th Asiatic gardn btl (Maladra castana). Survys hav indicatd that th orintal btl has bcom th most important whit grub spcis in Nw Jrsy and som nighboring aras. Thus, th avrag whit grub spcis composition in Nw Jrsy hom lawns in th fall of 200 (5 countis, 6 sits, in primarily th cntral part of th stat) was 63% orintal btl, 4% Asiatic gardn btl, 9% maskd chafrs, 8% Japans btl, 4% May/Jun btl (Phyllophaga spp.), and 2% grn Jun btl (Koppnhöfr t al., unpublishd data). Howvr, spcis composition can vary considrably among sits. Bcaus ths spcis can vary significantly in suscptibility to diffrnt control agnts, propr spcis idntification can b critical. Th safst way to idntify whit grub spcis in th larval stag is to xamin th rastr pattrn just in front of th anal slit on th grub s undrsid. Idntification is th asist whn th grubs ar big, fat, and sassy 3 rd instar larva, but at this point, th damag is oftn alrady don or impnding. Thrfor, idntification should b don whn grub populations ar bing monitord to dtrmin whthr curativ tratmnts ar ncssary (i.., in mid-august). Although th gnral lif cycl of th important whit grub spcis is vry similar, th gg-laying priod (major targt for prvntiv tratmnts) and accordingly th occurrnc of th voracious 3 rd larval stag can vary by a fw wks btwn spcis; anothr rason for obtaining knowldg about th prvalnt spcis in a turf sit. btls mrg btwn Jun and August, mat, and th fmals rturn into th soil to lay ggs (total of about 20 to 60) in svral batchs ovr a priod of 2 to 4 wks. Th gg, st larval, and 2 nd larval stags ach last about 3 wks so that through Sptmbr most of th grubs will molt to th 3 rd and last larval stag. Th voracious fding of ths larg grubs, whn combind with host and dry conditions, can rsult in quick and xtnsiv loss of turf from lat August through mid- Octobr. As th soil tmpraturs cool down, th grubs mov to dpr soil layrs to stay blow th frost lin. During this tim most spcis ar mor or lss inactiv. As th soil tmpraturs warm up in spring, th grubs com up to th root zon to fd for anothr 4 to 6 wks in l and May bfor thy pupat in th soil. Spring applications against whit grubs ar oftn inffctiv bcaus of th larg siz of th larva and th cool soil tmpraturs. In addition, cool-sason grasss can gnrally outgrow th grub fding in spring. Spcial control considrations by whit grub spcis Th gg-laying priod of th orintal btl (Tabl ) is btwn lat Jun and lat July. Most of th grubs molt into th 3 rd stag during Sptmbr. Effctiv curativ control agnts ar Dylox and Diazinon. Assistant Extnsion Spcialist in Turfgrass Entomology, Dpartmnt of Entomology, Cook Collg, Rutgrs, Th Stat Univrsity of Nw Jrsy, 55 Dudly Rd., Nw Brunswick, NJ Rutgrs Turfgrass Procdings

4 Dylox kills mor quickly than Diazinon and may b mor ffctiv latr in th yar and in spring. and prsist for long priods in th soil and ar applid as prvntivs. has a shortr prsistnc than and should not b applid bfor Jun. Howvr, th orintal btl is not vry suscptibl to (avrag control rat has bn blow 70%) and should b applid as clos to th gg laying priod as possibl for maximum fficacy. Th gg-laying priod of th Japans btl (Tabl 2) is btwn arly July and mid-august. Most of th grubs molt into th 3 rd stag during Sptmbr. Dylox is similarly ffctiv against Japans btl as against orintal btl but Diazinon is not ffctiv. Howvr, unlik many othr whit grub spcis Japans btl grubs can b ffctivly controlld with th insct-parasitic nmatod Htrorhabditis bactriophora. is similarly ffctiv against Japans btl as against orintal btl. Th Japans btl is among th most suscptibl whit grub spcis and this product can b applid vry ffctivly from Jun through mid-august. Japans btl is also th only spcis against which th commrcially availabl milky spor powdr can provid slow acting but long trm supprssion. Th gg-laying priod of maskd chafrs (Tabl 3) (th common spcis in Nw Jrsy is th northrn maskd chafr) is arlir and mor concntratd than for most othr whit grub spcis, i.., from mid- Jun to mid-july. Accordingly, most of th larva molt into th 3 rd stag arlir, i.., from mid-august to arly Sptmbr and srious damag may occur arlir if this spcis dominats. Effctiv curativs ar Dylox and Diazinon. Maskd chafr grubs can also b controlld with H. bactriophora, although not as ffctivly as Japans btl grubs. Maskd chafrs ar lss suscptibl to than orintal and Japans btl and th product should b applid as clos to th gg-laying priod as possibl and at th highst allowd labl rat. is highly ffctiv against maskd chafrs. Th gg-laying priod of th Asiatic gardn btl (Tabl 4) is from July to mid-august and most of th larva will molt to th 3 rd stag during Sptmbr and arly Octobr. Obsrvations on suscptibility of this spcis ar vry limitd. Dylox and Diazinon should provid control of this spcis. Howvr, both prvntivs, and, ar inffctiv vn with optimal timing. HAIRY CHINCHBUG Th hairy chinch bug (Tabl 5), Blissus lucoptrus hirtus, is an important pst of cool-sason grasss and zoysiagrass in th Northast. is causd by both th nymphs and th adults that suck juics from stms and crowns and injct saliva that clogs up th plants conductiv tissus. is most common during hot and dry priods in July to August and on sunny thatchy lawns. If th grass is in summr dormancy during this priod, th damag oftn gos unnoticd until th grass dos not rcovr aftr a good rain or irrigation. Th hairy chinch bug has two gnrations pr yar. Th ovrwintrd adults bcom activ in l and start laying ggs. Th nymphs dvlop through 5 stags bfor th final molt into th adult stag in Jun to July. Ths adults lay ggs from arly July through August and th nxt adult gnration appars from arly August through Sptmbr. Th bst way to control chinch bugs is through curativ spot tratmnts in Jun if monitoring has dtctd potntially damaging population lvls. Any labld pyrthroid or Diazinon or Svin can b applid. Prvntiv applications of th sam inscticids in spring bfor th ovrwintrd fmals start laying ggs should only b don if high chinch bug populations ar dtctd at that tim and if th aras hav a history of chinch bug infstations. Ths prvntiv applications ar oftn wastd bcaus natural nmis such as big-yd bugs and th insctpathognic fungus Bauvria bassiana oftn supprss chinch bug outbraks. In addition, th prvntiv application will ffctivly control thos vry natural nmis and also can ncourag inscticid rsistanc. Rathr, aras with prnnial chinch bug problms should b ovrsdd with ndophyt-nhancd grasss that ar rsistant to chinch bugs. BILLBUGS Billbugs (Tabl 6), Sphnophorus spcis, ar among th most misdiagnosd turfgrass psts, thir damag oftn bing confusd with symptoms of drought strss, disass such as dollar spot or brown patch, or injury from grn bugs or whit grubs. is don by larval fding, insid th stm by th young smallr larva, and latr through xtrnal fding on crowns, roots, or rhizoms by th matur larva. starts with scattrd dad stms of a whitish-straw color that latr grow togthr into 200 Rutgrs Turfgrass Procdings

5 patchs of dad turf. Th dad stms brak off at th crown and ar hollowd out or filld with sawdust-lik matrial or frass. is most common in mid- to lat summr, spcially during xtndd dry priods. Until rcntly it was assumd that th blugrass billbug, Sphnophorus parvulus, was th only billbug causing damag in th Northast, but rcnt studis at Rutgrs hav indicatd that othr spcis including th hunting billbug (S. vnatus vstitus), th small billbug (S. minimus), and th unvn billbug (S. inqualis) may b similarly important. Billbugs hav on gnration pr yar. Th blugrass billbug ovrwintrs in th adult stag. Th adults bcom activ again in lat l to mid-may whn thy can b sn disprsing from thir ovrwintring quartrs ovr sidwalks or similar xposd surfacs to turf aras. Fmals will lay up 200 ggs ach in May through arly July insid grass stms. Th ggs hatch in about 6 days. As th growing larva bcom too big to stay insid th stms, larva bcom abundant in th soil from arly July to arly August. Aftr pupation in th soil, th mrging nxt gnration of adults is abundant in lat summr and fall bfor sking out ovrwintring quartrs. Th sasonal distribution of th othr billbug spcis in Nw Jrsy is not wll undrstood but is probably similar. Howvr, th prsnc of larva is likly to b mor xtndd ovr th growing sason than if only th blugrass billbug wr prsnt, making optimal timing of control masurs mor difficult. Th bst tim for curativ tratmnts is whn th larva ar starting to mov from th stms into th soil around mid-jun. Diazinon, Svin, and th insct-parasitic nmatods Stinrnma carpocapsa or H. bactriophora ar ffctiv at this tim. In highrisk aras whr high adult numbrs wr obsrvd migrating in spring or aras with prnnial infstation, larva can b controlld prvntivly with applications of or from lat l into Jun. Altrnativly, prvntiv tratmnts of any labld pyrthroid or Diazinon can b applid in spring bfor th adults start laying ggs. Th optimal timing for adult tratmnts can b pinpointd through monitoring with pit-fall traps. SOD WEBWORMS Mor than 20 spcis of sod wbworm (Tabl 7) can caus damag to turf in th USA with typically two or thr spcis having th potntial to caus damag in a givn ara. Common spcis in Nw Jrsy includ th blugrass sod wbworm, Parapdiasia ttrrlla, and th largr sod wbworm, Pdiasia triscta. is causd by th larva that fd at night from silkn tunnls wovn in th thatch or surfac soil and chw off lavs and stms just abov th crown. bgins as gnral thinning, followd by patchs of brown, closly croppd grass. Wak or drought strssd grass may di du to sun xposur of crowns. Sod wbworms hav two or thr gnrations pr yar. Thy ovrwintr as partially grown larva in th soil or thatch and rsum fding in spring, typically pupating in May to Jun in th soil. Th fmals drop svral hundrd ggs on th wing into th turf that hatch in about 7 days. Larval dvlopmnt through six to ight larval stags taks 4 to 7 wks. Sod wbworms can b tratd curativly on an as ndd bas using th insct parasitic nmatods S. carpocapsa and H. bactriophora, th biorationals and Consrv, or Diazinon, Dylox, Svin, and Addrss/Orthn. ARMYWORMS Although quit spctacular whn thy occur, armyworm (Tabl 8) outbraks ar vry rar in th Northast bcaus th armyworms do not ovrwintr wll and hav to immigrat as moths vry yar from mor southrn latituds by hitchhiking on larg storm systms. In addition, armyworms gnrally prfr small grain, corn, or pasturs to turfgrasss as hosts. Th larva fd in larg groups and mow th grass down to th crown. With adquat irrigation, frtilization, and patinc, th grass will gnrally rcovr wll. Armyworms cannot b controlld prvntivly, but onc dtctd, thy ar asy to control. If thy ar alrady larg, any labld pyrthroid, Svin, Diazinon, or Addrss/Orthn should b usd to quickly kill thm. If thy ar dtctd whil still small, thy can also b controlld with th slowr acting control agnts such as th nmatod S. carpocapsa or th biorationals Consrv, Bt-products, or. MULTIPLE TARGETS Bcaus of thir long prsistnc, th prvntivs and can b usd to control mor than on insct pst in a givn growing sason (Tabls 9 and 0). Howvr, kp in mind that whil mor than on insct pst usually can b found in a givn turfgrass ara, rarly dos mor than on of thm caus damag in yar in th sam location. Tabls 9 and 0 show for and, rspctivly, how th windows of application to control diffrnt insct pst 200 Rutgrs Turfgrass Procdings

6 ovrlap for ach of th two products. If th turfgrass managr has rason to bliv that mor than on insct pst has th potntial to caus problms in a givn ara, th application tim should b chosn to optimiz th control of all targts. If, howvr, gnrally only on pst causs rgular and significant damag, th turfgrass managr should carfully wigh th bnfits of potntially controlling mor than th major targt vrsus compromising optimal control of th major pst problm. 200 Rutgrs Turfgrass Procdings

7 200 Rutgrs Turfgrass Procdings Tabl. Sasonal distribution of orintal btl lif-stags, occurrnc of damag, and timing and choics of inscticids. Pst Orintal btl Egg Larva (L-3) (L2) L 3 / Targ t Dylox Curativ / L2-3 Diazinon Curativ / L2-3 Prvntiv / E-L 2 Prvntiv / E-L 2 Low abundanc of lif stag, low risk of damag, and sub-optimal timing of inscticid application.

8 200 Rutgrs Turfgrass Procdings Tabl 2. Sasonal distribution of Japans btl lif-stags, occurrnc of damag, and timing and choics of inscticids. Pst Japans btl Egg Larva (L-3) (L2) L 3 / Targ t Dylox Curativ / L2-3 H. bactriophora Curativ / L2-3 Prvntiv / E-L 2 Prvntiv / E-L 2 Low abundanc of lif stag, low risk of damag, and sub-optimal timing of inscticid application.

9 200 Rutgrs Turfgrass Procdings Tabl 3. Sasonal distribution of maskd chafr lif-stags, occurrnc of damag, and timing and choics of inscticids. Pst Maskd chafrs Egg Larva (L-3) (L2) L 3 / Targ t Dylox Curativ / L2-3 Diazinon Curativ / L2-3 H. bactriophora Curativ / L2-3 Prvntiv / E-L 2 Prvntiv / E-L 2 Low abundanc of lif stag, low risk of damag, and sub-optimal timing of inscticid application.

10 200 Rutgrs Turfgrass Procdings Tabl 4. Sasonal distribution of Asiatic gardn btl lif-stags, occurrnc of damag, and timing and choics of inscticids. Pst Asiatic gardn btl Egg Larva (L-3) (L2) L 3 / Targ t Dylox Curativ / L2-3 Diazinon Curativ / L2-3 Low abundanc of lif stag, low risk of damag, and sub-optimal timing of inscticid application.

11 200 Rutgrs Turfgrass Procdings Tabl 5. Sasonal distribution of hairy chinch bug lif-stags, occurrnc of damag, and timing and choics of inscticids. Pst Hairy chinch bug Nymph (N-5) / Targ t Pyrthroids Prvntiv / A Diazinon / Svin Prvntiv / A N3- A Pyrthroids Curativ / N- A Diazinon / Svin Curativ / N- A Low abundanc of lif stag, low risk of damag, and sub-optimal timing of inscticid application.

12 200 Rutgrs Turfgrass Procdings Tabl 6. Sasonal distribution of blugrass billbug lif-stags, occurrnc of damag, and timing and choics of inscticids. Pst Blugrass billbug Egg Larva L / Targ t S. carpocapsa Curativ / L H. bactriophora Curativ / L Diazinon / Svin Curativ / L Pyrthroids Prvntiv / A Diazinon Prvntiv / A Prvntiv / L Prvntiv / L Low abundanc of lif stag, low risk of damag, and sub-optimal timing of inscticid application.

13 200 Rutgrs Turfgrass Procdings Tabl 7. Sasonal distribution of sod wbworm lif-stags, occurrnc of damag, and timing and choics of inscticids. Pst Sod wbworm Egg Larva (L-7) L4-7 / Targ t Curativ / L Consrv / Dylox Curativ / L S. carpocapsa Curativ / L Diazinon / Svin Curativ / L Addrss / Orthn Curativ / L Low abundanc of lif stag, low risk of damag, and sub-optimal timing of inscticid application.

14 200 Rutgrs Turfgrass Procdings Tabl 8. Sasonal distribution of common armyworm lif-stags, occurrnc of damag, and timing and choics of inscticids. Pst Common armyworm Egg Larva (L-8) L4-8 / Targ t Consrv Curativ / L Curativ / L S. carpocapsa Curativ / L Addrss / Orthn Curativ / L Diazinon Curativ / L Low abundanc of lif stag, low risk of damag, and sub-optimal timing of inscticid application.

15 200 Rutgrs Turfgrass Procdings Tabl 9. Ovrlap of windows for application of against important turfgrass insct psts. Ps t Orintal btl Japans btl Maskd chaf r Blugrass billbu g Optimal timing of inscticid application. Sub-optimal timing of inscticid application. Tabl 0. Ovrlap of windows for application of against important turfgrass insct psts. Ps t Orintal btl Japans btl Maskd chaf r Blugrass billbu g Sod wbwor m Optimal timing of inscticid application. Sub-optimal timing of inscticid application.