C. H. PICKETT, L. T. WILSON, AND D. GONZALEZI Department of Entomology, University of California, Davis, California 95616

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1 Popultion Dynmics nd ithinplnt Distribution of th strn Flowr Thrips (Thysnoptr: Thripid), n ErlySson Prdtor of Spidr Mits Infsting Cotton C. H. PICKETT, L. T. ILSON, AND D. GONZALEZI Dprtmnt of Entomology, Univrsity of Cliforni, Dvis, Cliforni Environ Entomol 17(3) (1988) ABSTRACT Th ssonlong popultion dynmics nd withinplnt distribution of th thrips Frnklinill occidntlis (Prgnd) wr xmind. Thrips dnsity ws highly vribl nd pkd in midsson. Fluctutions in dnsity in combintion with chnging g structur of th popultion suggst tht migrtion plys n importnt rol in th popultion dynmics of thrips. Th ssonl pk in thrips dnsity corrspondd with th priod of pk bloom Adult thrips wr strongly ttrctd to cotton flowrs, which suggsts tht th migrtory ntur of thrips is in prt cusd by thir prfrnc for flowr Structurs. ithinplnt distribution of thrips on minstm nod lvs is brod nd lrgly ovrlps tht of spidr mits, Ttrnychus spp, pry of thrips in rlysson cotton. Th combind minstm nd brnch nod distribution of thrips shows tht during most of th sson, thrips r cntrlly loctd in th plnt cnopy. KEY ORDS Insct, Frnklinill occidntlis, cotton, nturl control THE ESTERN FLOER thrips, Frnklinill occidntlis (Prgnd), hs bn considrd pst of cotton for mny yrs (Gins 1934, tts 1937). Dmg to th picl mristm by F. occidntlis or by othr psts cn dly crop mturity nd my rduc yilds in shortsson cotton (i.., northrn Txs [ilson 1982, Lsr 1985, rd 19851). Howvr, in rgions with wrmr springs such s Cliforni, chmicl pplictions ginst thrips r rrly wrrntd, s sdlings cn outgrow dmg nd compnst for ny pprcibl rduction in plnt vigor (Ellington t l. 1984, Ligh 1985). Furthrmor, chmicl pplictions incrs th liklihood of spidr mit, Ttrnychus spp., outbrks by rducing dnsitis of nturl nmis (Huffkr t l. 197, McMurtry t l. 197). Rcnt fild obsrvtions in cotton suggst F. occidntlis is n omnivor nd consquntly n importnt rlysson prdtor of spidr mits (Gonl t l. 1982, Gonl & ilson. 1982). Thir prdtory rol hs bn furthr lucidtd in lbortory studis on cotton nd pnuts (Boykin t l. 1984, Trichilo & Ligh 1986). At prsnt, howvr, no dtild fild studis hv bn conductd to quntify th rol of F. occidntlis s prdtor of spidr mits in cotton. Bing gnrlist fdr, F. occidntlis will probbly ttck ny pry smllr thn itslf. Thrfor, th rol of F. occidntlis s prdtor of spidr mits will dpnd to lrg xtnt on th mount of ovrlp btwn th distribution of th I Currnt ddrss: Division of Biologicl Control, Univrsity of Cliforni, Rivrsid, Clif rspctiv prdtor nd its pry. This ppr rports on th withinplnt distribution of F. occidntlis in rltion to spidr mits in cotton. Mtrils nd Mthods Popultions of F. occidntlis wr monitord during th 1982 fild sson t th Univrsity of Cliforni st Sid Fild Sttion nr Fiv Points, Clif. Plnts wr smpld wkly from plot (c..25 h) mbddd within n 8h fild of Acl SJ2 cotton. Cotton ws plntd 15 April, nd th furrow ws irrigtd nd mngd using stndrd culturl prctics. No inscticids or cricids wr pplid during th growing sson. Popultions of thrips on cotton in cntrl Cliforni r known to consist lmost ntirly of F. occidntlis (T. Ligh, prsonl communiction). Two smpling progrms, ch with diffrnt objctiv, wr conductd. In th first, smpling ws inititd 27 My, nd th numbr nd loction of thrips on th minstm nod (MSN) lvs of 2 rndomly slctd plnts wr rcordd wkly in th fild until 3 August. Spidr mit, Ttrnychus spp., dnsitis lso wr monitord during this progrm. Th proportion of spidr mitinfstd lvs ws rcordd from 4 rndomly slctd plnts, on lf pr plnt, ch lf slctd from th MSN s dfind in ilson t l. (1983). Th rsulting dt wr usd to gnrt ssonl stimts of thrips dnsity nd thir vrticl or MSN distribution on lvs nd th proportion of spidr mitinfstd lvs. Th nods on th minstm of th plnt wr numbrd in two wysfrom th cotyldon nd from th trminl. Th 46225x/88/551559$2./ 1988 Entomologicl Socity of Amric

2 5S2 ENVIRONMENTAL ENTOMOLOGY Vol. 17, no. 3 t 8 cc v, LT I I LL : w m H 3 Z Z s Thrips.9.. Spidr Mits I $ wo 9 lo lj loo My 29 Jun19 July 6 July 19 July 31 Aug.13 Fig. 1. PHYSIOLOGICAL TIME (DEGREE DAYS> 12 C) Popultion dynmics of thrips (F. occtdntlis) nd spidr mits in cotton. t first md if possibl to compr th mn MSN loction nd disprsl of thrips up th plnt with prviously rportd dt of spidr mits (ilson t l. 1983). Th scond ws usd whn discussing th withinplnt distribution nd mn MSN loction of thrips in th bsnc of spidr mits. Th MSN loction rcordd in this mnnr fcilittd th futur discussion nd dvlopmnt of smpling plns (ilson t l., unpublishd dt). Th mn rltiv loction (MRL) of thrips for ch smpl dt, stimtd s th mn MSN loction (trminl nod, 1) dividd by th mn numbr of MSNs possssing lvs, ws dtrmind bcus th MSN loction dos not lwys rflct th loction of thrips rltiv to th plnt cnopy. During th lttr prt of th growing sson, bsl lvs snsc whil th plnt continus to gin nw lvs in th trminl rgion. As rsult, th distribution of lvs shifts upwrd throughout th sson rltiv to th loction of MSNs. Th scond, mor intnsiv, smpling procdur ws conductd during shortr priod of tim (7 July24 August) nd providd informtion on th MSN distribution s wll s ltrl or brnch stm Tbl 1. Prcntg of totl thrips found on cotton structurs Dt Adults % of totl thrips Lrv Fruiting Fruiting Lvs structurs Flowrs Lvs structurs Flowrs (squrs/bolls) (squrs/bolls) 7, 8 July July , 21 July , 28 July , 5 Aug Aug , 18 Aug Aug

3 Jun 1988 PICKETT ET AL.: FIELD DYNAMICS OF ESTERN FLOER THRIPS L I I I I I 1 I I I I 1 I MK) 9 loo l( D PHYSIOLOGICAL TIME (DEGREE DAYS > 12 C) Fig. 2. Proportion of lrv in thrips popultion during cotton growing sson (n, 2). nod (BSN) distribution of thrips within th cotton plnt s influncd by plnt growth nd dvlopmnt. Th distribution of dult nd lrvl thrips ws rcordd from 3 to 1 rndomly slctd plnts cut, plcd in plstic bgs, nd countd in th lbortory on or two tims pr wk. On ch smpl dt, th loction of thrips with rspct to MSN, BSN, nd plnt prt (lf, squr, flowr, or boll) ws rcordd for lrvl nd dult thrips. From ths dt th proportion of thrips on diffrnt plnt structurs nd th combind MSNBSN distribution of thrips ws clcultd for ch smpl dt. Physiologicl tim rportd in our rsults ws xprssd s dgr dys (DD) >12"C from plnting (Gutirr t l. 1975). All rithmticl nd sttisticl computtions wr conductd using progrmming nd procdurl softwr dvlopd by th SAS Institut, Inc. (SAS Institut 1985,b). Rsults nd Discussion Th numbr of F. occidntlis pr plnt during th growing sson ws highly vribl, fluctuting from 3.5 k.43 to 49.4 k 5.85 (11 k SE). Thr mjor popultion pks r discrnibl whn numbrs of dult nd lrvl thrips r combind (Fig. 1). Two possibl fctors cusing fluctutions in thrips dnsitis r gnrtion pks nd migrtion. Th priod btwn th first nd scond pk in thrips dnsity is pproximtly 2.5 wk or 25 DD, similr to gnrtion priods during th summr of closly rltd spcis, Frnklinill tritici (Fitch) (Lwis 1973). Th tim btwn th scond nd third pk, howvr, ws lss thn 1 d, suggsting othr fctor(s) wr involvd in cusing th shrp fluctution in thrips dnsity. Fluctutions in popultion dnsity lso my b rltd to th migrtion of thrips btwn diffrnt flowring plnt spcis. F. occidntlis hs wid host rng of plnts, including 139 spcis in Cliforni (Bryn & Smith 1956). A rcnt study of Yudin t l. (1986) shows tht dults of F. occidntlis r highly ttrctd to flowrs. Th proportion of dult thrips found on fruiting structurs (squrs, flowrs, nd bolls) in our study pkd during midsson nd rprsntd mjor proportion (68%) of ll dult thrips found. Most of ths dult thrips wr rcordd from th flowr itslf (Tbl 1). Thr ws no similr ris in th proportion of totl lrv rcordd from flowrs or combind fruiting structurs. This tim priod corrsponds to th pk dnsity of thrips (Fig. I), s wll s th pk bloom priod of cotton. Apprntly

4 554 ENVIRONMENTAL ENTOMOLOGY Vl. 17, no h MEAN NUMBER OF MSN A NYMPHS ADULTS v) b K 4 ". ' A~ m AA m Bm 4 t.. A A O " AA A m 5 I A h A A s 5 LL lo l PHYSIOLOGICAL TIME (DEGREE DAYS > 1 2OC) Fig. 3. Disprsl of thrips up MSN lvs nd production of MSN. nithr th incrsing spidr mit popultion nor th incrsing plnt growth of cotton during th lttr prt of th sson fvord popultions of F. occidntlis, which dcrsd during th sm priod of tim (Fig. l). Ths rsults support prvious work by Gonl t l. (1982) nd Gonl & ilson (1982), who found tht, in th southrn Sn Joquin Vlly during pk bloom, dult F. occidntlis wr mor bundnt on flowring structurs thn on othr prts of cotton plnts. Florl nctr nd polln rprsnt dditionl food sourcs for dult thrips, whrs lrv most likly fd primrily on spidr mits nd lf tissu (Trichilo 1985). Ths rsults lso gr with findings on othr gnrlist fdrs in cotton, which show tht th dult stg hs grtr ffinity for fruiting structurs comprd with immtur stgs (ilson & Gutirr 198). Th proportion of lrv vrid ovr tim, first incrsing nd thn dcrsing, with most vlus flling btwn.5 nd.95 (Fig. 2). Popultions composd primrily of immturs nd incrsing in numbrs, s shown with thrips in our study (Fig. 1 nd 2), r considrd rproductivly stbl (Cry 1983). Th dclining proportion of lrv in lt sson, in combintion with th dcrsing popultion dnsity, indicts dclining rt of rproduction mong dult fmls. Fcundity my b dpndnt in prt on th consumption of polln grins from cotton flowrs which dclin in numbrs in lt sson (Ellington t l. 1984). Th mn MSN loction of F. occidntlis nd MSN production during th summr showd similr pttrns of chng (Fig. 3). Erly in th sson, both incrsd rpidly, but ltr thy incrsd mor slowly. Th rt of nod production nd concomitnt vrticl plnt growth ws gnrlly mor rpid thn th upwrd disprsl of thrips. Th MSN loction of thrips rchd c. nod 17 of th totl 23 MSNs in lt sson. Spidr mits disprs up th plnt during th sson in wy similr to thrips but much mor rpidly in mid to lt sson, nd thir mn MSN loction rchs th trminl lvs by lt sson (ilson t l. 1983). Diffrncs in disprsl pttrns btwn thrips nd spidr mits my b ttributd in prt to diffrncs Fig. 4. (A) Mn loction of combind dult, lrvl thrips rltiv to th plnt cnopy (n, 2). (B) Mn loction of dult thrips rltiv to th plnt cnopy (n. 2).

5 t E n n (r t I U > I cr: Z 2 t O3 OS.1 Ac7uALvwJEs ESTIMATED VALUES ** * * I I 1 I I I I 1 I I I I t oc n n (r t Y l > l.i CE 2 o.6t ADULTS : ACTUAL VALUES ADULTS : ESTIMATED VALUES ' I I I I I I I I I I I I I lo ( PHYSIOLOGICAL TIME (DEGREE DAYS > 1 2OC)

6 556 PERCENT ENVIRONMENTAL ENTOMOLOGY LARVAE Vol. 17, no. 3 3 i MAY 27 PERCENT 41 ADULTS 2 I UGUST 3 MAINSTEM NODES FROM TERMINAL DATE OF SAMPLING Fig. 5. ithinplnt frquncy distribution of thrips on lvs ssocitd ivith MSNs of cotton. in mods of migrtion nd fding hbits. Spidr mits r winddisprsd, th plnt trminl srving s point of dprtur (Flschnr t l. 1956, Hussy & Prr 1963, Mitchll 197). Spidr mits r strictly phytophgous. As food qulity dcrss in lt sson, thy will ctivly sk nw sourcs of food, ithr highr in th plnt cnopy or by moving off th plnt. Thrips r wingd nd r probbly lss dpndnt on ir currnts whn sking nw hbitts. Thy r lso omnivors nd not foodlimitd in lt sson. Although thrips do not disprs s high up th minstm s mits, thir upwrd movmnt ovr th sson suggsts thy, too, r sking nw hbitt. Thir upwrd dis

7 Jun 1988 PICKETT ET AL.: FIELD DYNAMICS OF ESTERN FLOER THRIPS 557 LARVAE ADULTS I AUGUST 24 AUGUST 24 1 JUY 2728 i JUY 2728 PERCENT 15.{ JULY 7 JULY 78 FROM TERMINAL BRANCH LOCATION Fig. 6. Ltrl (BSN) nd vrticl (MSN) withinplnt distribution of thrips on cotton. prsl my b in rspons to bundnt spidr mits, youngr lvs, nd flowrs, ll loctd highr in th cnopy s th plnt gs. Th mn rltiv loction of thrips within th plnt cnopy (trminl nod, 1) is plottd in Fig. 4A. Th significnt (P <.1) linr trnd in ths dt (Eqution 1) indicts th MRL of thrips movd slightly highr in th cnopy ovr th sson: MRL = DD; r? =.66, n = 27 (1) Erly in th sson, thrips wr most bundnt in th middl rgion of th plnt cnopy (MRL =.5), but in lt sson thy wr most bundnt in th uppr third of th cnopy (MRL =.3). In contrst to lrv, th MRL of dult thrips ovr tim producd distinct curvilinr pttrn (Fig. 4B) which is dscribd using fourth dgr polynomil rgrssion qution: MRL = (4.153*13) (2).DD (9.273*1') *DD + (7.22*19).DD' (2.*11Z).DD'; r =.86, n = 27, P <,1 Adult thrips disprsd to thir highst loction

8 558 ENVIRONMENTAL ENTOMOLOGY Vol. 17, no. 3 (lowst MRL) in midsson (95 DD) immditly following th ssonl pk in thrips dnsity nd corrsponding with th pk in squr production. Th subsqunt incrs in MRL occurrd s th dnsity of thrips ws dcrsing. Th ltsson MRL vlu most likly rsultd from loss of dults in th uppr prt of th plnt bcus of migrtion nd highr rt of mortlity rthr thn n incrs in thrips dnsity on MSN lvs lowr in th cnopy. Othr cotton rthropods r rportd to disprs up th dvloping cotton plnt (ilson t ]. 1982, ilson t l. 1983, Von Arx t l. 1984). Th distribution of lrvl thrips on MSN lvs during th growing sson ws rltivly brod, xcpt for 27 My (Fig. 5). Th prcntg of thrips t individul nods vrid btwn nd 2, with most thrips rcordd from nods 212 (trminl nod, 1). Th distribution of lrv s wll s dults on 27 My (th rlist smpling dt) diffrd mrkdly from th distributions shown for th othr thr smpl dts. Th cotton plnt t this tim is lss thn third of its finl hight, rstricting th thrips to much nrrowr rng of vilbl MSN lvs. Furthrmor, th trminl nod consists of both th MSN lf nd primordil tissus, ll highly ttrctiv to thrips. Th MSN distribution of dult thrips ws lso brod but mor vribl thn for lrv. Th prcntg of dults on MSN lvs (xcpt for 27 My) vrid btwn nd 25. Th grtr vribility in th distribution of dult thrips comprd with lrv my rflct th lss mobil lifstyl of lrv. Adults, bing wingd, cn mor rdily mov up, down, or off th plnt. Th mn MSN loction of thrips nd spidr mits is comprd ovr th ntir growing sson by xtrpolting from Fig. 3 nd using dt from ilson t l. (1983). Th MSN distributions of F. occidntlis nd spidr mits wr vry similr in rly sson whn plnts wr lss thn 2 nods tll nd in lt sson whn 172 nods tll. An ovrlp of th distributions of th thrips nd th spidr mits in rly sson is importnt bcus prdtion t this tim cn hv mjor impct on mid nd ltsson dnsitis of spidr mits. ilson t l. (1987) dmonstrtd tht rduction of rlysson spidr mit infsttion foci cn substntilly incrs th finl yild of cotton. Although th mn MSN loctions of ths two rthropods diffr during most of th sson, thir ovrll MSN distributions r brodly ovrlpping. Mor thn 93% of thrips (Fig. 5) nd spidr mits (ilson t l. 1983) smpld btwn 22 Jun nd 15 July wr found on MSN lvs 312. Thir ovrlpping distributions, combind with vidnc of high rts of prdtion by thrips on spidr mits (Trichilo & Ligh 1986), suggst tht th thrips hv th potntil of xrting lrg dgr of mortlity on th spidr mit popultion, t lst during th rly sson. Fig. 6 shows th distribution of thrips long th ltrl xis (BSN loction) of th plnt nd how this distribution chngs from th top (MSN = 1) to th bottom of th cnopy on thr diffrnt smpling dts. Thrips loctd in th uppr portion of th plnt (bov MSN 5) wr found primrily on MSN lvs whr fw othr plnt prts wr vilbl to thm. Th mjority of lrv blow minstm 5 wr found on firstposition BSN lvs. Th sm ws obsrvd for dult thrips, xcpt in midsson. During this priod, whn th lrgst numbr of flowrs ws found on th plnts, most dult thrips wr loctd on fruiting structurs. Of ths plnt prts, most dult thrips wr found on flowrs (Tbl 1). Th prfrnc by dult thrips for flowrs is suggstd by thir shifting to ths incrsingly vilbl structurs during midsson. Thrips wr rcordd lmost xclusivly from ithr firstposition BSN plnt prts or on MSN lvs, lthough structurs frthr out on brnchs wr vilbl (Fig. 6). Th limitd distribution of thrips within th plnt cnopy suggsts F. occidntlis my prfr hbitt protctd from dirct sunlight nd wind, s do othr spcis of thrips (Lwis 1973). Thy my lso b ttrctd to lvs infstd with spidr mits or to lvs of highr nutritionl qulity. Acknowldgmnt Th uthors thnk Rx Frisn for ssistnc in fild nd lbortory work, Pggy Kpln for typing this mnuscript, nd Mik Hoffmnn for his commnts nd criticl rviw. Rfrncs Citd Boykin, L. S.,. V. Cmpbll & M. K. But Effct of psticids on Noygits floridun (Entomophthorls: Entomophthorc) nd rthropod prdtors ttcking th twospottd spidr mit (Acri: Ttrnychid) in North Crolin pnut filds. J. Econ. Entomol. 77: Bryn, D. E. & R. F. Smith Th Frunklinillu occidntlis (Prgnd) complx in Cliforni (Thysnoptr: Thripid). Univ. Clif. Publ. Entomol. 1: Cry, J. R Prcticl ppliction of th stbl g distribution: nlysis of ttrnychid mit (Acri: Ttrnychid) popultion outbrk. Environ. Entomol. 12: 118. Ellington, J., A. G. Gorg, H. M. Kmpn, T. A. Krby, L. Moor, B. B. Tylor & L. T. ilson Intgrtd pst mngmnt for cotton in th wstrn rgion of th Unitd Stts. Univrsity of Cliforni Agriculturl nd Nturl Rsourcs Publiction 335. Flschnr, C. A., N. E. Bdgly, D.. Rickr & J. C. Hll Air drift of spidr mits. J. Econ. Entomol. 49: Gins, J. C A prliminry study of thrips on sdling cotton with spcil rfrnc to th popultion, migrtion nd injury. J. Econ. Entomol. 27: Gonl, D. & L. T. ilson A foodwb pproch to conomic thrsholds: squnc of psts/ prdcous rthropods on Cliforni cotton. Entomophg 27: 3143.

9 Jun 1988 PICKETT ET AL.: FIELD DYNAMICS OF ESTERN FLOER THRIPS 559 Gonl, D., B. R. Pttrson, T. F. Ligh & L. T. ilson Mits: primry food sourc for two prdtors in Sn Joquin Vlly cotton. Clif. Agric. 36(2, 3): 182. Gutirr, A. P., L. A. Flcon,. Low, P. A. Lipig & R. vn dn Bosch An nlysis of cotton production in Cliforni: modl for Acl cotton nd th ffct of dfolitors on its yilds. Environ. Entomol. 4: Huffkr, C. B., M. vn d Vri & J. A. McMurty Ecology of ttrnychid mits nd thir nturl nmis: rviw. Prt 11. Ttrnychid popultions nd thir possibl control by prdtors: n vlution. Hilgrdi 4: Hussy, N.. &. J. Prr Disprsl of glsshous rd spidr mit Ttrnychus urtic Koch (Acrin, Ttrnychid). Entomol. Exp. Appl. 6: Ligh, T. F Erl) sson insct control for Cliforni. Procdings strn Cotton Production Confrnc. Univrsity of Cliforni, Cooprtiv Extnsion. Lsr, J. F Dvlopmnt of thrips mngmnt strtgy for th Txs High Plins. Procdings strn Cotton Production Confrnc. Univrsity of Cliforni, Cooprtiv Extnsion. Lwis, T Thrips, thir biology, cology nd conomic importnc. Acdmic Prss, Nw York. McMurty, J. A., C. B. Huffkr, nd M. vn d Vri Ecology of ttrnychid mits nd thir nturl nmis, rviw. Prt I. Ttrnychid nmis: thir biologicl chrctrs nd th impct of spry prctics. Hilgrdi 4: Mitchll, R An nlysis of disprsl in mits. Amr. Nt. 14: SAS Institut SAS usr s guid: sttistics. SAS Institut, Cry, N.C. 1985b. SAS usr s guid: bsics. SAS Institut, Cry, N.C. Trichilo, P. J Influnc of host plnt on th intrction of spidr mits with thir nturl nmis in cotton grocosystm. Ph.D. dissrttion, Univrsity of Cliforni, Dvis. Trichilo, P. J. & T. F. Ligh Prdtion of spidr mit ggs by th wstrn flowr thrips, Frnklinill occidntlis (Thysnoptr: Thripid), n opportunist in cotton grocosystm. Environ. Entomol. 15: Von Arx, R., J. Bumgrtnr & V. Dlucchi Smpling of Bmisi tbci (Gnn.)(Strnorrhynch: Alyrodid) in Sudns cotton filds. J. Econ. Entomol. 77: rd, C. R Erly sson cotton pstsn IPM prspctiv from th Nw Mxico Pcos Vlly. Procdings strn Cotton Production Confrnc. Univrsity of Cliforni, Cooprtiv Extnsion. tts, J. G Rduction of cotton yilds by thrips. J. Econ. Entomol. 3: ilson, L. T Growth nd fruiting dvlopmnt of norml nd trminldmgd cotton plnts. Environ. Entomol. 11: ilson, L. T. & A. P. Gutirr ithinplnt distribution of prdtors on cotton: commnts on smpling nd prdtor fficincis. Hilgrdi 48: 123. ilson, L. T., A. P. Gutirr & D. B. Hogg ithinplnt distribution of cbbg loopr, Trichoplusi ni (Hubnr) on cotton: dvlopmnt of smpling pln for ggs. Environ. Entomol. 11: ilson, L. T., D. Gonl, T. F. Ligh, V. Mggi, C. Foristir & P. Goodll ithinplnt distribution of spidr mits (Acri: Ttrnychid) on cotton: dvloping implmntbl monitoring progrm. Environ. Entomol. 12: ilson, L. T., C. H. Picktt, T. F. Ligh & J. R. Cry Spidr mit (Acri: Ttrnychid) infsttion foci: cotton yild rduction. Environ. Entomol. 16: Yudin, L. S., J. J. Cho &. C. Mitchll Host rng of wstrn flowr thrips, Frnklinill occidntlis (Thysnoptr: Thripid), with spcil rfrnc to Lucn gluc. Environ. Entomol. 15: Rcivd for publiction 15 July 1987; ccptd 11 Fbrury 1988.