STRATEGIES FOR APHID MANAGEMENT IN ALFALFA. Ayman M. Mostafa 1 INTRODUCTION

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1 STRATEGIES FOR APHID MANAGEMENT IN ALFALFA Aymn M. Mostf 1 INTRODUCTION Alflf is n importnt commodity for diry nd livestock enterprises nd is the first in terms of crege plnted in Arizon nd second to lmond in Cliforni. It domintes the cropping systems in the Western US given the importnce of the diry industry nd other livestock enterprises. Alflf is considered the insectry of the west; providing refuge to wildlife nd vriety of beneficil insects, improves soil chrcteristics, contributes to tmospheric nitrogen fixtion through rhizobcteri, trps sediments nd tkes up nitrte pollutnts, mitigtes wter nd ir pollution, nd provides ppeling nd plesing open lndscpe. Alflf lso plys n importnt role in insecticide resistnce mngement by cting s refuge for susceptible genotypes; e.g., the sweetpotto whitefly Bemisi tbci Genndius. Beneficil insects move from lflf fields into other crops, where they ply crucil roles in pollintion nd biologicl control. Brodspectrum insecticides use in lflf ffect beneficil insect popultions nd cuses potentil longterm effects cross the entire lndscpe. A complex of four lflf phids in the region, pe phid (PA) Acyrthosiphon pisum (Hrris), the blue lflf phid (BAA) Acyrthosiphon kondoi L., the spotted lflf phid (SAA), Theriophis mcultto (Buckton), nd the cowpe phid, (CPA), Aphis crccivor C.L. Koch. The first two phids re the most common nd dngerous in the southwest desert of the U.S. The Aphid popultions re highest in the winter nd spring months when the first cuttings of the yer occurred. These first cuttings re in high demnd for the diry industry. The spotted lflf phid ws the first nd most devstting lflf phid outbrek on record in This SAA outbrek destroyed millions of cres of lflf in the U.S. Severl insecticideresistnt SAA biotypes were identified (Stern nd Reynolds, 1958; Nielson nd Don 1974). Consequently, resistnt lflf vriety line ws produced in respond of the SAA outbrek (Nielson et l. 1970) Cowpe phid outbrek in the lte-1980 s in the Imperil Vlley (Ntwick 1991) cusing serious injury to lflf nd moved northwrd nd estwrd (Ntwick 1999, 1999b, 1999c; Summers 2000, 2000b) ttcking lflf in most lflf producing regions cross the U.S. (Berberet et l. 2009). A CPA-resistnt lflf vrieties were relesed in By 1975, reports showed declining in the efficcy of chemicl controls of pe phid in lflf fields in the region (Shrm et l. 1976). Tht followed by the estblish of blue lflf phid in 1 A. Mostf (ymn@cls.rizon.edu), Are Agent, Field Crops IPM, Regionl Specilist, College of Agriculture nd Life Sciences, Coopertive Extension, University of Arizon, Phoenix, AZ In: Proceedings, 2017 Western Alflf nd Forge Symposium, Reno, NV, Nov UC Coopertive Extension, Plnt Sciences Deprtment, University of Cliforni, Dvis, CA (See for this nd other lflf conference Proceedings.)

2 the desert production re of lflf in the lte 80 s. The PA nd BAA, re similr in size nd color nd often occur in mixed popultions so they re esily misidentified. The BAA spred quickly cross the U.S., prticulrly in wrmer regions (Nielson nd Kodet 1975; Nielson et l. 1976) nd it ws first esily controlled by different groups of insecticides (Shrm et l. 1975). However, BAA re-infesttion ws extremely quick nd difficult to control. BAA-resistnt lflf vrieties such s CUF 101 were developed (Nielson et l. 1976b) nd economic threshold levels were lso reported (Shrm nd Stern 1980). In 2013, BAA re-emerged s the most serious lflf phid in the low elevtion desert of Cliforni nd Arizon, nd the problem quickly spred northwrd (Brlow nd Ntwick 2013, Rmirez, unpublished, Mostf, unpublished). Although lflf pest mngement prctices hve worked, t different degrees, for phid mngement over the lst 40 yers, new chllenges hve risen, minly the lck of softer chemistry options, mono cropping nd the bsence of mjor IPM tools like prcticl smpling method, well-studied economic threshold, timing of insecticide pplictions, proper understnding of the roles nd conservtion of nturl enemies. Brodspectrum insecticides such s orgnophosphtes nd pyrethroids re frequently used in lflf production to control phids. If not used correctly, these insecticides re destructive to nturl enemy popultions, pose risks to pplictor helth, nd hve mny environmentl concerns such s contmintion of wterwys, nd non-trget effect. Lower risk selective insecticides re vilble for sucking insects such s phids, however they re slow in getting registered for lflf, more expensive nd less likely to be used s first choice. Most lflf fields re treted with insecticides t lest once nnully for phid control, but since the spring of 2013, growers in CA nd AZ hve been using chemicls multiple times during the seson to control BAA. In the pst 5 10 yers, insecticide pplictions per seson use hve incresed due in prt to higher hy prices nd qulity demnds from the diry industry. Insecticide cost for lflf rnges from $12 $40 per cre, which represents bout 2-5% of production costs. Some Pest Control Advisors (PCAs) nd growers hve reported lower insecticide efficcy compred to previous yers. In 2011, need ssessment survey mong growers nd griculturl professionls in AZ indicted tht different pyrethroids, s well s chlorpyrifos nd mlthion, ll brod-spectrum insecticides, ccount for 100% of the insecticides pplied to control lflf weevil nd phids, the mjor nd most destructive winter/spring lflf pests in the region. Diry nd livestock industries re continuously demnding higher qulity product, thus, to meet this gol, mny growers hve incresed their chemicl control pproch to decrese pest dmge. In low desert lflf production res, phid popultions re highest in the winter nd spring months when the highly demnded, premium qulity first cuttings of the yer occurred. Strting 2015 we observed infections of lflf phids in centrl nd western Arizon with entomopthogenic fungi. These infections spred to Cliforni nd then northwrd. The entomopthogenic fungl infection persisted nd incresed through seson; giving n indiction of long term presence of this entomopthogenic fungus in the region. The work proposed in this project is prt of lrger ongoing reserch nd extension IPM progrm to develop improved IPM prctices for lflf weevil nd lflf phid complex, key lflf pests, develop their economic thresholds, verify their use in commercil fields, study

3 efficcies of vilble insecticides, promote nd evlute doption nd impct of new prctices through coordinted outrech progrm. INSECTICIDE EFFICACY TRIALS FOR BAA AND PA Severl insecticide efficcy tril for BAA nd PA hve been conducted by Aymn Mostf t the University of Arizon Mricop Agriculturl Center from Ech tretment replicted four times in Rndomized Complete Plot Design (RCPD). Ech plot mesured 20 x 20 ft with 5 ft lley between plots. Insecticide tretments were pplied using modified John Deere Hi-Cycle with 6-row boom nd compressed ir system. All sprys were delivered with trctormounted, ground-rig t 20 GPA (c. 30 psi, TeeJet TwinJet 8003 nozzles, 24 per plot, brodcst over the top). Eight, seven, elven, eight nd eleven tretments were tested in 2014 tril I, 2014 tril II, 2015, 2016 nd 2017, respectively. Evlutions of tretment effects were mde by estimtions of number of phids per 5 stems from the rdil of ech plot. Smples were processed by using pint brush nd beting on white sheet. Aphids were sorted to species by microscope. A mechnicl yield of 75 sq ft ws hrvested from the middle of ech plot t he time of regulr cut using Crter hrvester. Sttisticl nlyses of ANOVA of tretment mens were conducted using SYSTAT 13 softwre. Comprisons of mens were tested using LSD contrsts. RESULTS AND DISCUSSIONS 2014 Efficcy Tril I Results of the two phid species re summrized in Figs. 1, 2 & 3. In generl, ll tretments were effective in tht there were fewer phids following the spry compred to the, with few exceptions. BAA ws the mjor concern of growers nd PCAs during tht time. For BAA nd totl phids, sttisticl nlyses showed tht the two rtes of Trnsform, Belef, Dimethote, nd the tnk mix of nd Mlthion 8 hve no significnt differences in term of their effects. Lorsbn nd Mlthion 8 hs no significnt differences compred to the. Similr trend hs been detected for the effects of tretments on hy yields (P = 0.005) (Fig. 4) Efficcy Tril II Results of the two phid species re summrized in Figs. 5, 6 & 7. Similr to Efficcy tril I, ll tretments were effective in tht there were fewer phids following the spry compred to the, with few exceptions. Sttisticl nlyses showed no significtion differences mong tretments in term of their effects on BAA nd PA popultions. However, ll tretments produced significntly higher hy yield compre to (P = 0.005) (Fig. 8) Efficcy Tril Sttisticl nlyses for insecticides tretment ginst BAA) nd PA t different smpling dys fter tretment (DAT), in summry, showed ll insecticide tretments hd fewer nd for some significntly fewer Aphid complexes thn the untreted plots during the whole experimentl period (Tble 1).

4 Sttisticl nlyses showed tht ll insecticides treted plots hd significntly (P<0.05) fewer BAA thn the untreted plots, 5 DAT (Tble 1). In the 11 DAT it ws only Trnsform t rte of 1 oz./a tht hd significntly fewer BAA when compred to untreted check. However, 18 DAT Trnsform, Pyrifluquinzon nd Coblt dvnced hd significnt effect ginst BAA s compred to untreted plots. At 25 DAT plots treted with Sivnto t both rtes (7.0 nd 10.5 oz./a), Pyrifluquinzon t rte of 3.2 oz./a, Belef 50 t rte of 2.85 oz./a, t rte of 9 oz. /A, nd Dimethote 4E t rte of 1 pt./a hd significntly (P<0.01) fewer BAA thn the untreted plots. However, there were no significnt differences mong the insecticides treted plots. Sivnto t both rte (7 oz./a & 10.5 oz./a), Coblt dvnced t rte of 24 oz./a, t rte of 1.92 oz./a nd Belef50 t rte of 2.85 oz./a insecticide tretments hd significntly fewer PA thn the untreted check for the 5 DAT. Ech insecticide tretment hd significntly fewer PA thn the untreted check t the 11 DAT. Belef 50, nd Pyrifluquinzon tretments hd significntly fewer PA thn the untreted check for the 18 DAT smplings. Post smpling t 25 DAT indicted tht plots treted both rtes of Sivnto nd Pyrifluquinzon, Dimethote, Belef 50 nd hd significntly fewer PA thn the check Efficcy Tril The infesttions of lflf phids both t experimentl sites nd commercil fields were lower in 2016 thn in recent yers. At the experimentl site, there ws significntly lower popultion of BAA (only 2 % BAA) thn Pe phids (87 % PA). Fungl infection ws observed in mny fields including the experimentl sites where up to 34% of BAA infected (Tble 2). This nturlly occurring entomopthogenic fungus, pprently decresed phid popultion. BAA ws the mjor concern of growers nd PCAs during the lst few yers. In 2016, the BAA popultion reched its lowest level in this re since we strt monitoring phids in lflf in Initil count (02/10/2016) ws mde dy before chemicl spry. Aphid popultion ws initilly 87% pe phid, 10% cowpe phid, nd 2% BAA nd only 1% SAA on stem bsis. However, the totl popultions of the four species were s low s two phids per stem. The 2016 result showed slight shift in popultion dynmics of phids popultion. BAA remrkbly infected by fungus compred to other species of phids (Tble 2). Unlike the pst three to four yers dt, popultion of Cowpe phid ws slightly higher thn tht of BAA popultion. However, popultions of BAA, CPA nd SAA remined lower throughout the smpling period both in treted nd untreted plots, only one to two phids per stem. Significnt differences in cumultive pe phid popultion nd over ll phids popultion resulted from the insecticidl tretments (Tble 3). Plots treted with Dimethote,, Belef50, Sivnto nd Trnsform insecticides hd significntly fewer pe phid-dys per stem thn did the untreted control. The rest of tretment hd fewer but not significntly different from untreted check. Generlly, ll insecticide treted plots resulted in higher yields s compred to the untreted check (Tble 3) Efficcy Tril Eleven insecticides were tested for their efficcies ginst phids in lflf, including were two microbil insecticides (PFR-97 & BotniGrd).

5 For the second consecutive yer there ws significntly lower popultion of BAA thn PA. The fungl infection ws repetedly seen in mny fields including the experimentl sites. Following the insecticide tretments pplied on Jnury 26, 2017, both PA nd BAA were very well controlled (Fig. 11). Some of the chemistries such s Sivnto 200SL, Coblt dvnced, Trnsform 50WG, Mustng nd provided the best control for the most bundnt PA. Mlthion & Gmm cyhlothrin nd including those mentioned bove controlled the less bundnt BAA more thn other insecticides. Generlly, the popultions of PA were low (less thn 18 per stem) t ny time of the week on untreted plots nd never exceed 17 in ny of the treted plots t ny time of the week. The cumultive pe phids popultion (sesonl totl pe phids) during the experimentl period ws less thn 60 phids per stem. Ech insecticides tretment hd significntly fewer sesonl PA thn the untreted check. Sivnto t rte of 10.5 oz./a, Coblt dvnced t rte of 26 oz./a, Trnsform t 1 Oz./A, Sivnto t rte of 7 oz./a, Mustng (4.3 oz./a), microbil insecticides PFR-97 (1 lb./a), nd ZCX (4.5 oz./a) hd fewer PA thn the other insecticides nd untreted check for the entire experimentl period (Figure 11). The popultion of BAA ws generlly lower thn tht of the PA this yer too. The sesonl BAA during the experimentl period ws less thn 5 on nd less thn 1 for Mlthion & Gmm cyhlothrin nd coblt dvnced treted plots. All insecticides treted plots hd fewer sesonl BAA thn untreted plots. The effect of microbil insecticides PFR-97 nd BotniGrd ppers to be cted differently on PA nd BAA. PFR-97 ppers to be effective on PA nd BotniGrd on BAA. Tretments were significntly different for dry-mtter yield (Figure 11). All insecticide treted plots resulted in higher yields s compred to the untreted check. Plots treted with Mlthion & Gmm cyhlothrin, Sivnto 200SL, Coblt dvnced,, nd Mustng exhibited the highest hy yield probbly becuse of the plots treted with them hd the lowest numbers of cumultive PA nd BAA/stem. The second highest yield ws recorded on plots treted with microbil insecticides PFR-97 in spite of higher popultion of phids found on this plot. Entomopthogenic fungi such s Beuveri bssin (commercil formultions, BotniGrd) nd Isri fumosorose (Pfr-97) re primrily used for controlling rthropod pests. Reserch in the recent yers evluted their endophytic (colonizing plnt tissues) nd mycorrhiz-like (ssocited with roots) reltionship with plnts nd potentil benefits in improving plnt growth nd helth. Studies conducted in Cliforni showed the fungus colonized strwberry plnts nd persisted for up to 9 weeks in vrious plnt tissues (Dr nd Dr, 2015); promoted strwberry plnt growth (Dr, 2013); nd negtively impcted green pech phids through endophytic ction (Dr 2016). Entomopthogenic fungi lso hve positive effect on promoting drought tolernce or plnt growth s seen in cbbge (Dr et l, 2016) nd strwberry (Dr, 2013) nd ntgonizing plnt pthogens (Dr et l, 2017). Entomopthogenic fungi typiclly cuse infection when spores come in contct with the rthropod host. Under idel conditions of moderte tempertures nd high reltive humidity, fungl spores germinte nd brech the insect cuticle through enzymtic degrdtion nd mechnicl pressure to gin entry into the insect body. Once inside the body, the fungi multiply, invde the insect tissues, emerge from the

6 ded insect, nd produce more spores. Fungl pthogens hve brod host rnge nd re especilly suitble for controlling pests tht hve piercing nd sucking mouthprts becuse spores do not hve to be ingested. The present higher yield on Isri fumosorose (Pfr-97) treted plots might hve contributed to those ll fctors tht the fungus positively ffects in promoting nd improving helthy lflf plnt growth. This is the first field study evluting the impct of the entomopthogenic fungus on lflf phids control nd yield of lflf in Arizon. Repeting similr study would result into conclusive remrks. Trnsfrom 1oz Trnsform 0.75oz Belef 50 Dimethote 4E Worrior II+ Mlthion 8 Lorsbn 4E Mlthion8 BAA 5 DAT BAA 12 DAT Trnsfrom 1oz Trnsform 0.75oz Belef 50 Dimethote 4E Worrior II+ Mlthion 8 Lorsbn 4E Mlthion BAA 19 DAT BAA 26 DAT Number of Blue lflf phids / stem Number of Blue lflf phids / stem Fig. 1: Number of blue lflf phids per stem for ech tretment 5, 12, 19 nd 26 dys fter tretments (DAT) in the insecticide efficcy tril (I) ginst phids in lflf t Mricop Agriculturl Center in 2014

7 Trnsfrom 1oz Trnsform 0.75oz Belef 50 Dimethote 4E Worrior II+ Mlthion 8 Lorsbn 4E Mlthion8 PA 5 DAT PA 12 DAT Trnsfrom 1oz Trnsform 0.75oz Belef 50 Dimethote 4E Worrior II+ Mlthion 8 Lorsbn 4E Mlthion PA 19 DAT PA 26 DAT Number of pe phids / stem Number of pe phids / stem Fig. 1b: Number of Pe phids per stem for ech tretment 5, 12, 19 nd 26 dys fter tretments (DAT) in the insecticide efficcy tril (I) ginst phids in lflf t Mricop Agriculturl Center in 2014

8 A 5 DAT 12 DAT 19 DAT 26 DAT Trnsform 1 Trnsform 0.75 Belef Dimethote Wrrior+Mlthion Lorsbn Mlthion b b b B 5 DAT 12 DAT 19 DAT 26 DAT Trnsform 1 Trnsform 0.75 Belef Dimethote Wrrior+Mlthion Lorsbn Mlthion Fig. 3: Sesonl men (4 post-spry dtes) of totl phids per stem (A = BAA, B = PA) for ech tretment in the insecticide efficcy tril (I) ginst phids in lflf t Mricop Agriculturl Center in 2014

9 5 DAT 12 DAT 19 DAT 26 DAT Trnsform 1 Trnsform 0.75 Belef Dimethote Wrrior+Mlthion Lorsbn b Mlthion b b Fig. 4: Number of totl phids per stem for ech tretment t 5, 12, 19 nd 26 dys fter tretments (DAT) in the insecticide efficcy tril (I) ginst phids in lflf t Mricop Agriculturl Center in 2014.

10 b bc bc bc c c cd d d Fig. 5: Men hy yield (bsed on 12% moisture) for the insecticide efficcy tril (I) ginst phids in lflf t Mricop Agriculturl Center in 2014.

11 BAA 5 D BAA 14 BAA 21 D Dimethote 4E Dimethote 4E Dimethote 4E Stllion Stllion Stllion Sivnto Sivnto Sivnto Coblt Advnced Coblt Advnced Coblt Advnced Number of BAA / stem Number of BAA / stem Number of BAA / stem PA 5 PA 14 PA 21 Dimethote 4E Dimethote 4E Dimethote 4E Stllion Stllion Stllion Sivnto Sivnto Sivnto Coblt Advnced Coblt Advnced Coblt Advnced Number of PA / stem Number of PA / stem Number of PA / stem Fig. 6: Number of totl phids per stem for ech tretment t 5, 14, nd 21 dys fter tretments (DAT) in the insecticide efficcy tril (II) ginst PA nd BAA in lflf t Mricop Agriculturl Center in 2014

12 A 5 DAT 14 DAT 21 DAT Dimethote 4E Stllion Sivnto Coblt Advnced B 5 DAT 14 DAT 21 DAT Dimethote 4E Stllion Sivnto Coblt Advnced Fig. 7: Sesonl men (3 post-spry dtes) of totl phids per stem (A = BAA, B = PA & C = CPA) for ech tretment in the insecticide efficcy tril (II) ginst phids in lflf t Mricop Agriculturl Center in 2014

13 5 DAT 14 DAT 21 DAT Dimethote 4E Stllion Sivnto Coblt Advnced Fig. 8: Number of totl phids per stem for ech tretment t 5, 14, nd 21 dys fter tretments (DAT) in the insecticide efficcy tril (II) ginst phids in lflf t Mricop Agriculturl Center in Dimethote 4E Stllion Sivnto Coblt Advnced b Yield (Ton / A) Fig. 9: Men hy yield (bsed on 12% moisture) for the insecticide efficcy tril (II) ginst phids in lflf t Mricop Agriculturl Center in 2014

14 Tble 1. Sttisticl Anlysis for Insecticides Tretment ginst Blue Alflf nd Pe Aphids t Different Dys of Smpling fter Tretment in Dys After Tretment (DAT) Tretment BAA PA BAA PA BAA PA BAA PA Belef50(2.85) 4.50 B* 4.50 BC 3.75 AB B 1.75 AB C 3.50 BC BC B ABC 7.25 AB 1.00 B 3.00 AB C 5.00 BC BC CobltAdvnced B 1.25 BC 4.50 AB 7.00 B 1.00 B ABC 8.00ABC ABC Dimethote4E B 14.00ABC 7.00 AB B 3.00 AB ABC 4.75 BC BC B 9.75 ABC 5.00 AB B 3.50 AB AB AB ABC Pyrifluquinzon B 14.00ABC 4.00 AB B 1.00 B BC 7.75 ABC ABC Pyrifluquinzon B AB 4.25 AB B 1.25 AB ABC 3.50 BC BC Sivnto B 0.50 C 5.50 AB B 2.25 AB ABC 4.50 BC 9.75 BC Sivnto B 2.25 BC 8.50 AB B 3.00 AB ABC 4.25 BC BC Trnsform B 7.00ABC 3.00 B B 1.00 B ABC 7.50 ABC ABC WrriorII B 3.00 BC 5.00 AB B 2.00AB ABC 7.25 ABC ABC A A 9.50 A A 5.00 A A A A *Mens within columns followed by the sme letter re not significntly different, LSD ; P= 0.05

15 Fig. 10: Aphids nturlly ffected by n entomopthogenic epizootics fungus in Centrl Arizon Tble 2. Percent popultion nd infection of lflf phids by fungus during the tril conducted in 2016 t Mricop Agriculturl Center (nd = no dt; 10-Feb dt were before spry)

16 Aphids Popultion BAA PA CP SA Dte % Pop % Infected % Pop % Infected %Pop % Infected %Pop % Infected Inches 10-Feb Feb Feb Mr 94 nd Mr 96 nd Stem Height Tble 3. Sttisticl Anlysis for Insecticides Tretment ginst Pe phids, Blue Alflf, Cowpe phids, nd spotted lflf phids nd sesonl totl of phids per stem in 2016 Yield Tons/A Sesonl PA Sesonl Sesonl Sesonl Sesonl BAA ns CPA ns SAA ns Totl Tretment ZCX 4.5oz/A 1.08 ABC 18 BC B Temitry EC 18oz/A 1.25 A 24 BC B Belef 50SG 2.85oz/A 1.08 ABC 26 BC B Trnsform50WG 1oz/A 0.98 BCD 29 BC B Mustng EW 4.3oz/A 1.12 AB 40 ABC AB Dimethote 4E 16oz/A 1.00 BCD 15 C B Sivnto SL 10.5oz/A 0.88 CD 47 AB AB Coblt Adv cd 32oz/A 1.25 A 44 ABC AB Untreted Control 0.81 D 61 A A *Mens within columns followed by the sme letter re not significntly different, LSD ; P= 0.05; ns-non significnt

17 A ABC AB ABC A 30 CD BCD D D D 25 D D YIELDS (LB/75 SQ.FT) M & Gc ZCX Coblt Advnced Mustng Dimethote Sivnto 10.5 Belef 50 Trnsform Sivnto 7 PFR 97 BotniGrd TREATMENTS PA BAA Yield Fig. 11. The effect of totl sesonl on hy yield in the 2017 insecticide efficcy tril t Mricop Agriculturl Center (MAC). Mens of yield with the sme letter re not significntly different from ech other t lph 0.05.

18 REFERENCES Dr, S. K Entomopthogenic fungus, Beuveri bssin promotes strwberry plnt growth nd helth. UCCE enewsletter Strwberries nd Vegetbles, 30 September, ( Dr, S. K. nd S. R. Dr Entomopthogenic fungus, Beuveri bssin endophyticlly colonizes strwberry plnts. UCCE enewsletter Strwberries nd Vegetbles, 17 Februry, ( Dr, S. K Endophytic Beuveri bssin negtively impcts green pech phids on strwberries. UCCE enewsletter Strwberries nd Vegetbles, 2 August, ( Dr, S. K., S.S.R. Dr, nd S.S. Dr First report of entomopthogenic fungi, Beuveri bssin, Isri fumosorose, nd Metrhizium brunneum promoting the growth nd helth of cbbge plnts growing under wter stress. UCANR ejournl Strwberries nd Vegetbles, 19 September, ( Dr, S.S.R., S. S. Dr, S. K. Dr, nd T. Anderson Fighting plnt pthogenic fungi with entomopthogenic fungi nd other biologicls. CAPCA Adviser 20 (1): Brlow, V. M. nd E. T. Ntwick Blue lflf phid issue summry. Alflf nd Forge News, My 20, Berberet, R. C., K. L. Giles, A. A. Zrrbi, nd M. E. Pyton Development, reproduction, nd within-plnt infesttion ptterns of Aphis crccivor (Homopter: Aphidide) on lflf. Environ. Entomol. 38: Godfrey, L., P. Goodell, V. Brlow, E. Ntwick nd R. Long In: Proc., 2013 Western Alflf & Forge Symp., Reno, NV, 11-13, December, UC Coop. Ext., Plnt Sci. Dept., Univ. Clif., Dvis, CA Humphrie, A. W., D. M. Peck, S. S. Robinson, T. Rowe, nd K. Oldch A new biotype of bluegreen phid (Acyrthosiphon kondoi Shinji) found in south-estern Austrli overcomes resistnce in brod rnge of psture legumes. Crop & Psture Science, 2012, 63, Ntwick, E. T Pest-O-Grm Nwsl. Jn 31, Ntwick, E. T Cowpe phids in lflf. Pest-O-Grm Nwsl. Jn 19. pp. 1. Ntwick, E. T. 1999b. Insecticide efficcy evlution for cowpe phid control in lflf, Imperil Agr. Briefs Nwsl. Apr pp. 6-7.

19 Ntwick, E. T. 1999c. New phid invdes Cliforni lflf fields, Clif. Alf. & Forge Assn. Rev. Vol.2, No.2. Ntwick, E.T., nd M. Lopez. Aphid nd whitefly mngement in lflf in Imperil Vlley, Cliforni. Proceedings 2004 Ntionl Alflf Symposium nd 34th Cliforni Alflf Symposium. pp Nielson, M. W., H. Don, M. H. Schonhorst, W. F. Lehmn, nd V. L. Mrble Biotypes of the spotted lflf phid in western United Sttes. J. Econ. Entomol. Vol. 63: Nielson, M. W. nd H. Don A new virulent biotype of the spotted lflf phid in Arizon. J. Econ. Entomol. 67:64-7 Nielson, M. W. nd R. T. Kodet The blue lflf phid in Arizon. In: 5th Clif. Alflf Symp., pp Nielson, M.W., L. Moore nd R. T. Kodet The blue phid rrives; Fr Estern pest invdes Arizon lflf fields. Progressive Agriculture in Arizon 28: Nielson, M. W., W. F. Lehmn nd R. T. Kodet, 1976b. Resistnce in lflf to Acyrthosiphon kondoi. J. Econ. Entomol., Vol. 69: Shrm, R. K., V. M. Stern nd R. W. Hgemnn Blue lflf phid dmge nd its control in the Imperil Vlley Cliforni. In: 5th Clif. Alflf Symp., pp Shrm, R. K., V. M. Stern, R. W. Hgemnn Blue lflf phid: A new pest in the Imperil Vlley. Clif. Agri. 30(4):14-15, doi# /c.v030n04p14 Shrm, R. K. nd V. M. Stern Blue lflf phid: Economic threshold levels in southern Cliforni. Clif. Agric. 34: Stern, V. M. nd H. T. Reynolds Resistnce of spotted lflf phid to certin orgnophosphorous insecticides in southern Cliforni. J. Econ. Entomol. 51: Summers, C. G Cowpe phid spreds. Clif. Alf. Forge Rev. vol. 2. University of Cliforni, Dvis, CA. Summers, C. G. 2000b. Tiny pest thretens Cliforni lflf crop. Clif. Alf. Forge Rev. vol. 3. University of Cliforni, Dvis, CA. Tuttle nd Butler, The yellow clover phid new lflf pest in the southwest. J. Econ. Entomol. 47:1157.