《植物病蟲害綠色防控技術(shù)》課件-四、甘薯病蟲害綠色防控（雙語(yǔ)）

四

甘薯病蟲害綠色防控

IV

GreenPreventionandControlofSweetPotatoDiseasesandPests

一甘薯黑斑病綠色防控I.

GreenPreventionandControlofSweetPotatoBlackSpot甘薯黑斑病

又稱黑疤病，黑膏藥、黑瘡等，目前已成為我國(guó)甘薯產(chǎn)區(qū)危害普遍而嚴(yán)重的病害之一。據(jù)統(tǒng)計(jì)，我國(guó)每年由該病造成的產(chǎn)量損失為5％～10％，危害嚴(yán)重時(shí)造成的損失為20％～50％，甚至更高。此外，病薯中可產(chǎn)生甘薯黑皰霉酮等物質(zhì)，人畜食用后，引起中毒，嚴(yán)重者死亡。Sweetpotatoblackspot,alsoknownastheblackscar,blackplaster,blacksore,etc.,hasbecomeoneofthecommonandseriousdiseasesinproducingareasofsweetpotatoinChina.Accordingtostatistics,theannualyieldlosscausedbythediseaseinChinais5%~10%,andthelosscausedbyseriousdamageis20%~50%orevenhigher.Inaddition,ipomeamaroneandothersubstancescanbeproducedindiseasedpotatoes,whichcancausepoisoninganddeathinseverecasesafterhumanandanimalconsumption.（一）癥狀

主要危害薯苗和薯塊。苗期癥狀

受侵染的幼芽基部產(chǎn)生凹陷的圓形或梭形小黑斑，以后逐漸縱向擴(kuò)大至3～5mm，嚴(yán)重時(shí)則環(huán)繞苗基部形成黑腳狀。地上部病苗衰弱，矮小，葉片發(fā)黃，重病苗死亡。

(I)SymptomsItmainlyharmssweetpotatoseedlingsandtubers.SymptomsatseedlingperiodAtthebaseofinfectedseedlings,concaveroundorspindlesmallblackspotsappear,andthengraduallyexpandto3~5mmlongitudinally.Inseverecases,blackrootformaroundthebaseofseedlings.Theabovegroundpartofthediseasedseedlingisweakandshort,theleavesturnyellow,andtheseriouslydiseasedseedlingdies.一甘薯黑斑病綠色防控I.

GreenPreventionandControlofSweetPotatoBlackSpot生長(zhǎng)期癥狀當(dāng)病苗移栽到大田后，生長(zhǎng)衰弱，葉片發(fā)黃脫落，遇干旱易枯死。病苗即使成活，結(jié)薯也少，產(chǎn)量極低。薯蔓上的病斑可蔓延到新結(jié)薯塊上，多在傷口處產(chǎn)生黑色斑塊。Symptomsatgrowthperiod

Whenthediseasedseedlingsaretransplantedtothefield,theirgrowthisweak,theleavesturnyellowandfalloff,andtheyareeasytodieincaseofdrought.Evenifthediseasedseedlingssurvive,therearefewpotatoesandtheyieldisextremelylow.Thespotsonthepotatovinescanspreadtothenewtubers,mostlyproducingblackspotsatthewounds.一甘薯黑斑病綠色防控I.

GreenPreventionandControlofSweetPotatoBlackSpot貯藏期癥狀病斑多發(fā)生在傷口和根眼上，初為黑色小點(diǎn)，逐漸擴(kuò)大成圓形、橢圓形或不規(guī)則形膏藥狀病斑，稍凹陷，直徑1～5cm不等，輪廓清晰。病部組織堅(jiān)硬，可深入薯肉2～3cm，薯肉呈黑綠色，味苦。Symptomsatstorageperiod

Thespotsmostlyoccuronthewoundsandrootholes.Itisinitiallyblackdotsandgraduallyexpandsintoround,oval,orirregularplaster-likespots,slightlysunken,withadiameterrangingfrom1~5cmandaclearoutline.Thetissueoftheaffectedpartishard,andcanpenetrateintothesweetpotatoby2~3cm.Thesweetpotatopresentsblack-greenandtastesbitter.一甘薯黑斑病綠色防控I.

GreenPreventionandControlofSweetPotatoBlackSpot（二）病原甘薯長(zhǎng)喙殼菌屬子囊菌亞門長(zhǎng)喙殼屬甘薯黑斑病菌1.分生孢子2.厚垣孢子3.子囊殼4.子囊殼基部剖面5.子囊6.子囊孢子(II)EtiologyCeratocystisfimbriataEllis.etHalstedbelongstotheCeratocystisofAscomycotinaFungusofsweetpotatoblackspot1.Conidia2.Chlamydospore3.Perithecium4.Basesectionofperithecium5.Ascus6.Ascospores一甘薯黑斑病綠色防控I.

GreenPreventionandControlofSweetPotatoBlackSpot（三）發(fā)病規(guī)律越冬：以子囊孢子、厚垣孢子和菌絲體在薯塊或土壤中病殘?bào)w上越冬。帶菌種薯和秧苗是主要的初侵染來(lái)源，其次是帶有病殘組織的土壤和肥料。侵入途徑：甘薯黑斑病病菌寄生性不強(qiáng)，主要由傷口侵染，也可從根眼、皮孔等自然孔口侵入。傳播：分生孢子和子囊孢子在田間主要靠種薯、種苗、土壤、肥料和人畜攜帶傳播。溫濕度：土溫在15～30℃適合發(fā)病，最適溫度為25℃；甘薯貯藏期間，當(dāng)溫度高于15℃時(shí)利于發(fā)病，最適發(fā)病溫度為23～27℃。

(III)OccurrenceRegularityOverwintering:Ascospores,chlamydospores,andmyceliumoverwinterontubersordiseasedresiduesinsoil.Theseedtubersandseedlingswithfungusarethemainsourcesofprimaryinfection,followedbysoilandfertilizerwithdiseasedandresidualtissues.Waysofintrusion:Thepathogenofthefungusofsweetpotatoblackspotisnothighlyparasiticandismainlyinfectedbywounds,andcanalsointrudebynaturalorificessuchasrootholsesandlenticels.Transmission:Conidiaandascosporesaremainlycarriedbyseedtubers,seedlings,soil,fertilizers,andhumansandanimalsinthefield.Temperatureandhumidity:Soiltemperatureof15~30°Cissuitableforthedisease,andtheoptimumtemperatureis25°C.Duringthestorageofsweetpotatoes,whenthetemperatureishigherthan15°C,itisconducivetothedisease,andtheoptimumtemperatureforthediseaseis23~27°C.一甘薯黑斑病綠色防控I.

GreenPreventionandControlofSweetPotatoBlackSpot

（四）防治技術(shù)

采取以清除初侵染來(lái)源為前提、精選無(wú)病種薯為基礎(chǔ)、培育無(wú)病壯苗為中心、安全貯藏為保證，實(shí)行以農(nóng)業(yè)防治為主、藥劑防治為輔的綜合防治措施。（1）清除侵染源

嚴(yán)格執(zhí)行檢疫制度，嚴(yán)禁從病區(qū)調(diào)運(yùn)種薯、種苗。育苗時(shí)不用病土、舊床土墊苗床，更新苗床土壤；大田收獲后，及時(shí)清除病源，集中將帶病殘?bào)w曬干焚燒或深埋。（2）建立無(wú)病留種田

選用無(wú)病薯苗栽插大田，采用高剪苗，結(jié)合藥劑浸苗，或在春薯蔓上剪蔓栽插夏薯；留種地要選3年未栽種甘薯的地塊，收獲的種薯要單收、單運(yùn)、單藏。（3）種薯的安全

薯塊入窖后，初期應(yīng)注意降溫排濕，當(dāng)氣溫下降時(shí)，應(yīng)及時(shí)封窖防凍，嚴(yán)格控制窖溫在10～14℃。黑斑病發(fā)生嚴(yán)重的地區(qū)，種薯入窖前，可用25%多菌靈可濕性粉劑250倍液浸種5min，涼干后再入窖。

(IV)ControlTechniqueComprehensivepreventionandcontrolmeasureswithagriculturalpreventionandcontrolasthemainstayandchemicalpreventionandcontrolasthesupplementshallbeimplementedonthepremiseofremovingtheprimaryinfectionsource,selectingdisease-freeseedtubersasthebasis,cultivatingdisease-freestrongseedlingsasthecenterandsafestorageastheguarantee.

(1)Removalofthesourceofinfection.Strictlyimplementthequarantinesystem,anditisstrictlyprohibitedtotransportseedtubersandseedlingsfromtheendemicarea.Whenraisingseedlings,donotusediseasedsoilandoldbedsoiltomattheseedbed,andrenewtheseedbedsoil.Afterharvestinginthefield,removethediseasesourceintime,andintensivelydry,burn,ordeeplyburythediseasedresidues.

(2)Establishmentofthedisease-freeseedfield.Selectdisease-freepotatoseedlingstoplantinthefield,usehigh-cuttingseedlings,soaktheseedlingswithchemicals,orcutthevinesonthespringpotatocranetoplantsummerpotatoes.Selectplotswheresweetpotatoeshavenotbeenplantedforthreeyearsastheseedfieldandharvestedseedtubersshouldbeharvested,transported,andstoredseparately.

(3)Safetyofseedtubers.Afterthetubersareputintothecellar,attentionshouldbepaidtocoolinganddehumidificationattheinitialstage.Whenthetemperaturedrops,thecellarshouldbesealedintimetopreventfreezing,andthecellartemperatureshouldbestrictlycontrolledat10~14°C.Inareaswithseriousblackspots,seedtuberscanbesoakedin1:250dilutionof25%carbendazimwettablepowderfor5minutesbeforebeingputintothecellar,andthenputintothecellarafterbeingcooledanddried.一甘薯黑斑病綠色防控I.

GreenPreventionandControlofSweetPotatoBlackSpot（4）培育無(wú)病壯苗

①精選種薯育苗時(shí)，做到種薯三選，即出窖時(shí)選，浸種時(shí)選，苗床排種時(shí)選。嚴(yán)格剔除病、蟲、傷及受凍薯塊。

②種薯消毒

種薯消毒處理可采用溫湯浸種和藥劑浸種。溫湯浸種：薯塊在51～54℃溫水中浸10min，可殺死附著在薯塊表面及潛伏在種皮下的病菌。由于種薯下水后要大量吸熱降溫，所以應(yīng)將水溫調(diào)節(jié)在56～58℃。藥劑浸種：因地制宜地選用浸種藥劑種類?？蛇x用70%甲基硫菌靈可濕性粉劑800～1000倍液浸種10min；或50%代森銨200～300倍液浸種10min。浸種液一次配藥可連續(xù)浸種薯10～15次。藥劑浸種不僅防病效果好，而且還有促進(jìn)出苗及生長(zhǎng)的作用。

(4)Cultivationofstrongdisease-andpest-freeseedlings①Thereselectionofseedtubersshouldbecarriedoutforcarefulselection,thatis,selectionwhenleavingthecellar,selectionwhensoakingseedtubers,andselectionwhenseedbedseeding.Strictlyremovediseases,insects,injuries,andfrozentubers.②Disinfectionofseedtubers.Soakinginwarmwaterandchemicalscanbeusedforthedisinfectionofseedtubers.Soakinginwarmwater:Soakingtubersinwarmwaterat51~54°Cfor10mincankillpathogensattachedtothesurfaceofpotatoesandlatentundertheseedcoat.Sinceseedtubersneedtoabsorbalotofheatafterenteringthewater,thewatertemperatureshouldbeadjustedto56~58°C.Soakingwithchemicals:Selectthetypesofchemicalsaccordingtolocalconditions.Theseedscanbesoakedin1:800~1,000dilutionof70%thiophanate-methylwettablepowdersfor10min,orin1:200~300dilutionof50%ammoniumsulfatefor10min.Theseedtuberscanbecontinuouslysoaked10~15timesafterthesolutionispreparedonce.Chemicalsoakingnotonlyhasagooddisease-preventioneffectbutalsopromotesseedlingemergenceandgrowth.一甘薯黑斑病綠色防控I.

GreenPreventionandControlofSweetPotatoBlackSpot③加強(qiáng)苗床管理

育苗時(shí)盡量采用新苗床，舊苗床應(yīng)清除全部舊床土，更換新土，并噴藥消毒，且施用無(wú)菌凈肥。④藥劑浸苗

將薯苗捆成小捆，在藥劑中浸秧苗基部，具有消毒防病作用。可用70%甲基硫菌靈可濕性粉劑800～1000倍液浸薯苗5min、50%多菌靈可濕性粉劑2500～3000倍液浸薯苗2～3min或10%雙效靈水劑400～500倍液浸薯苗10min。（5）選用抗病品種

因地制宜選用抗病品種，目前生產(chǎn)上推廣應(yīng)用的抗病品種主要有蘇薯8號(hào)、豫薯4號(hào)、渝蘇303、渝蘇153、鄂薯2號(hào)、冀薯4號(hào)等。（6）加強(qiáng)栽培管理

實(shí)行輪作倒茬，旱地種植3年以上輪作或旱地和稻田輪作。同時(shí)采用起壟栽培，合理施用肥水，增施不帶病菌的有機(jī)肥，防止薯塊開(kāi)裂，及時(shí)防治地下害蟲和田鼠。③Strengthenseedbedmanagement.Newseedbedsshouldbeusedasfaraspossibleduringseedlingraising.Alltheoldseedbedsoilshouldberemoved,replacedwithnewsoil,disinfectedbysprayingchemicals,andappliedwithsterilecleanfertilizer.④Seedlingssoakingwithchemicals.Bundlepotatoseedlingsintosmallbundlesandsoakthebaseofseedlingsinthechemicalfordisinfectionanddisease-prevention.Theseedlingscanbesoakedwith1:800~1,000dilutionof70%thiophanate-methylwettablepowderfor5min,1:2,500~3,000dilutionof50%carbendazimwettablepowderfor2-3min,or1:400~500dilutionof10%shuangxiaolingsolutionfor10min.(5)Selectionofdisease-resistantvarieties.Selectdisease-resistantvarietiesaccordingtolocalconditions.Atpresent,thedisease-resistantvarietiespopularizedandappliedinproductionmainlyincludeSushu8,Yushu4,Yushu303,Yushu153,Eshu2,Jishu4,etc.(6)Strengthencultivationmanagement.Croprotationshallbecarriedout,andcroprotationshallbecarriedoutindrylandformorethan3yearsorindrylandandricefields.Atthesametime,ridgingcultivationisadopted,fertilizerandwaterarereasonablyapplied,andorganicfertilizerwithoutpathogensisaddedtopreventtubersfromcrackingandpreventundergroundpestsandrodentsintime.一甘薯黑斑病綠色防控I.

GreenPreventionandControlofSweetPotatoBlackSpot

甘薯軟腐病

俗稱水爛病，為甘薯貯藏期的主要病害之一。該病發(fā)分布廣泛，全國(guó)各甘薯生產(chǎn)區(qū)均有發(fā)生，常在貯藏期發(fā)生腐爛，造成不同程度的損失。（一）

癥狀識(shí)別

薯塊變軟腐爛，表面生有棉絮狀灰白色菌絲體，后期上有黑色小點(diǎn)。切開(kāi)病薯塊，薯內(nèi)呈淡褐色，維管束褐色較深，可流出汁水，有芳香酒味。二甘薯軟腐病綠色防控II.

GreenPreventionandControlofSweetPotatoSoftRo

Softrotofsweetpotato.Itiscommonlyknownaswaterrot,whichisoneofthemaindiseasesduringthestorageperiodofsweetpotatoes.ThediseaseoccurswidelyinallsweetpotatoproductionareasinChina,andoftenrotsduringstorage,causinglossestodifferentdegrees.(I)Symptomidentification

Thetubersbecomesoftandrotten,withcottonflocculentgrayish-whitemyceliumonthesurfaceandblackdotsonthelaterstage.Whenthediseasedtubersarecut,thetubersarelightbrown,andthevascularbundlesaredarkbrown,withsapflowingoutandthearomaofalcohol.甘薯軟腐病為害薯塊癥狀甘薯軟腐疬為害薯塊橫切面癥狀SymptomsofTuberDamagedbySoftRotSymptomsofCrossSectionofTuberDamagedbySoftRot二甘薯軟腐病綠色防控II.

GreenPreventionandControlofSweetPotatoSoftRo根霉屬（二）病原物分類地位：接合菌亞門根霉屬；孢囊梗：直立，叢生于匍匐絲上，下端生有假根；孢子囊：球形，內(nèi)有半圓形的囊軸及大量的孢囊孢子；孢囊孢子：?jiǎn)伟?，褐色，橢圓形，表面有條紋；接合孢子：黑褐色，近球形，表面有刺狀物。孢子囊（Sporangia）假根（Rhizoid）Rhizopus(II)PathogensTaxonomicstatus:RhizopusofZygomycotina;Sporangiophores:Erect,clusteredonstolons,withrhizoidsatthelowerend;Sporangia:Spherical,withsemicircularcolumellaandalargenumberofsporangiospores;Sporangiospores:Amerosporous,brown,oval,withstripesonthesurface;Zygospores:Black-brown,nearlyspherical,withspinesonthesurface.二甘薯軟腐病綠色防控II.

GreenPreventionandControlofSweetPotatoSoftRo接合孢子（Zygospore）二甘薯軟腐病綠色防控II.

GreenPreventionandControlofSweetPotatoSoftRo（三）

發(fā)生規(guī)律

該菌存在于空氣中或附著在被害薯塊上或在貯藏窖越冬，由傷口侵入。病部產(chǎn)生孢子囊借氣流傳播進(jìn)行再侵染，薯塊有傷口或受凍易發(fā)病。發(fā)病適溫15～25℃，相對(duì)濕度76%～86%。

該病菌的腐生能力較強(qiáng)，寄主范圍也較廣，除甘薯外，還可為害多種作物的果實(shí)，花和貯藏器官。病原菌以孢子囊經(jīng)氣流及農(nóng)事操作等傳播，一般從薯塊端部或其它部位的傷口侵入。

病害的發(fā)生與薯塊的生活力強(qiáng)弱關(guān)系密切，薯塊本身生活力旺盛，病害不會(huì)發(fā)生，只有薯塊受凍后，生活力降低，病菌才容易侵入。薯塊傷口多，帶蔓貯藏等都有利于病害發(fā)生。(III)OccurrenceRegularity

Thefungusispresentintheairorattachedtotheinfectedtubersoroverwintersinthestoragecellarandinvadesfromwounds.Thesporangiaproducedbytheaffectedpartsaretransmittedbyairflowforreinfection,andtuberswithwoundsorfrozenarepronetothedisease.Theoptimumtemperatureforonsetis15~25°Candtherelativehumidityis76%~86%.Thepathogenhasastrongsaprophyticabilityandawidehostrange.Inadditiontosweetpotatoes,theycanalsodamagethefruits,flowers,andstorageorgansofvariouscrops.Thepathogenicbacteriaistransmittedbysporangiathroughairflowandagriculturaloperationsandgenerallyinvadesfromthewoundsattheendoftubersorotherparts.Theoccurrenceofthediseaseiscloselyrelatedtotheviabilityofthetuber.Thetuberitselfhasstrongviability,sothediseasewillnotoccur.Onlyafterthetuberisfrozen,theviabilityisreduced,andthepathogeniseasytoinvade.Tuberswithmanywoundsandarestoredwithvines,whichareconducivetotheoccurrenceofdiseases.二甘薯軟腐病綠色防控II.

GreenPreventionandControlofSweetPotatoSoftRo（四）

防治技術(shù)

1、適時(shí)收獲，防止薯塊受凍害

一般甘薯15℃以下即停止生長(zhǎng)，9℃以下會(huì)遭受冷凍害，因此收獲期掌握在旬平均氣溫在14～15℃時(shí)為宜，霜降前收獲完畢，當(dāng)天收獲當(dāng)天入窖，以免夜間遭受冷凍。

2、精選種薯入窖

凡帶病、蟲、傷及受冷、凍害薯塊應(yīng)嚴(yán)格剔除，運(yùn)輸過(guò)程中盡量減少傷口，保證貯藏質(zhì)量。

3、選好窖址，做好舊窖消毒

提倡用新窖，舊窖要清理干凈，或把窖內(nèi)日土鏟除露出新土，必要時(shí)用硫磺熏蒸，用硫磺15g/m3。消毒時(shí)應(yīng)密閉兩天，然后通氣使用。

(IV)ControlTechnique1.Harvestintimetopreventtubersfromfreezingdamage.Generally,thegrowthofsweetpotatoesstopswhenthetemperatureisbelow15°C,andfreezingdamagewilloccurwhenthetemperatureisbelow9°C.Therefore,itisadvisabletocontroltheharvestperiodwhentheten-dayaveragetemperatureis14~15°C.AfterharvestingbeforeFrost'sDescent,putthepotatoesintothecellaronthesamedayofharvesttoavoidfreezingatnight.2.Puttingselectedseedtubersintothecellar.Alltuberswithdiseases,pests,injuries,coldinjuries,andfreezinginjuriesshouldbestrictlyremoved,andwoundsshouldbeminimizedduringtransportationtoensurestoragequality.3.Selectthecellarsiteandcarryoutdisinfectionfortheoldcellar.Itisrecommendedtouseanewcellar.Theoldcellarshouldbecleanedup,orthedailysoilinthecellarshouldberemovedtoexposethenewsoil.Ifnecessary,itshouldbefumigatedwithsulfurof15g/m3.Itshouldbesealedfortwodaysandthenventilatedforuse.二甘薯軟腐病綠色防控II.

GreenPreventionandControlofSweetPotatoSoftRo

4、加強(qiáng)貯藏期管理

應(yīng)根據(jù)不同窖型掌握好窖內(nèi)溫、濕度及通氣情況，甘薯入窖初期的15～20d內(nèi)，薯塊呼吸作用強(qiáng)，濕度大，應(yīng)敞開(kāi)窖門，散去水分，晚上或雨天應(yīng)關(guān)閉窖門，待窖溫穩(wěn)定在10～14℃，應(yīng)封閉窖門，冬季保持恒溫，必要時(shí)應(yīng)加覆蓋物保溫。春季氣溫回升后，隨氣溫變化逐漸開(kāi)窖通風(fēng)，防止后期病害發(fā)生。4.Strengthenthemanagementofthestorageperiod.Thetemperature,humidity,andventilationinthecellarshallbewellcontrolledaccordingtodifferentcellartypes.Within15~20daysafterthesweetpotatoesareputintothecellar,thetubershavestrongrespirationandhighhumidity,sothecellardoorshouldbeopenedtodispersemoistureandthecellardoorshouldbeclosedatnightoronrainydays.Whenthecellartemperatureisstabilizedat10~14°C,thecellardoorshouldbeclosedandkeptataconstanttemperatureinwinter.Coveringsshallbeaddedforthermalinsulationifnecessary.Afterthetemperaturerisesinspring,graduallyopenthecellarforventilationwiththechangeoftemperaturetopreventdiseasesinthelaterperiod.二甘薯軟腐病綠色防控II.

GreenPreventionandControlofSweetPotatoSoftRo（一）

發(fā)生與為害情況

甘薯麥蛾又名甘薯卷葉蟲，屬鱗翅目，麥蛾科。目前我國(guó)除新疆、寧夏、青海、西藏等地未見(jiàn)報(bào)道外，全國(guó)各地都有發(fā)生，且以南方各省發(fā)生較重。主要為害甘薯、蕹菜、山藥、月光花、牽?；ǖ刃浦参铩?/p>

以幼蟲為害，幼齡幼蟲剝食葉肉，但不卷葉，幼蟲稍大后，可以吐絲將葉卷起，幼蟲在卷葉內(nèi)啃食一面表皮和葉肉，留下另一面表皮，呈薄膜狀，并將糞便排在卷葉內(nèi)。此外，幼蟲還能食害幼芽，嫩莖和嫩梢。發(fā)生嚴(yán)重時(shí)，大量葉片被卷綴，葉肉幾乎被食盡，整片地呈現(xiàn)“火燒”現(xiàn)象，嚴(yán)重影響甘薯產(chǎn)量和品質(zhì)。三甘薯麥蛾綠色防控III.

GreenPreventionandControlofSweetPotatoLeaf-folder

(I)OccurrenceandDamage

BrachmiamacroscopaMeyrick,alsoknownassweetpotatoleaf-folder,belongstoGelechiidaeofLepidopter.Atpresent,ithasnotbeenreportedinXinjiang,Ningxia,Qinghai,Tibet,andotherplacesinChina,butithasoccurredalloverthecountry,anditismoreseriousinsouthernprovinces.ItmainlydamagesConvolvulaceaesuchassweetpotato,waterspinach,yam,moonflower,andmorningglory.Thelarvaedamageplants.Younglarvaepeeloffmesophyllbutdonotrollleaves.Whenthelarvaeareslightlyolder,theycanspinsilktorolluptheleaves.Thelarvaenibbleononesideoftheepidermisandmesophyllintherolledleaves,leavingtheothersideoftheepidermisinafilmshape,anddischargefecesintherolledleaves.Inaddition,thelarvaecanfeedonyoungbuds,tenderstems,andshoots.Inseverecases,alargenumberofleavesarecurledupandthemesophyllisalmosteatenup,showinga"fire"phenomenoninthewholearea,whichseriouslyaffectstheyieldandqualityofsweetpotatoes.三甘薯麥蛾綠色防控III.

GreenPreventionandControlofSweetPotatoLeaf-folder三甘薯麥蛾綠色防控III.

GreenPreventionandControlofSweetPotatoLeaf-folder（二）形態(tài)識(shí)別1、成蟲

體長(zhǎng)5～7mm，翅展15～18mm，體黑褐色。前翅狹長(zhǎng)，暗褐色或銹褐色，中室內(nèi)有2個(gè)黑色小點(diǎn)，翅外緣有5個(gè)的小黑點(diǎn)。后翅較寬，淡灰色，緣毛較長(zhǎng)。2、卵

長(zhǎng)約0.6mm，橢圓形，表面有細(xì)的縱、橫脊紋，初產(chǎn)時(shí)灰白色，后變?yōu)榈S色，近孵化前一端出現(xiàn)小黑點(diǎn)。3、幼蟲

老熟時(shí)體長(zhǎng)18～20mm，頭稍扁，黑褐色。前胸背板褐色，兩側(cè)具暗褐色倒“八”字形紋。中胸至腹部第2節(jié)背面黑色，以后各節(jié)乳白色，亞背線黑色，第2～6腹節(jié)每節(jié)兩側(cè)各有1條黑色斜紋。4、蛹

體長(zhǎng)7～8mm，紡錘形，黃褐色。頭鈍尾尖，體上被細(xì)毛。臀棘末端有鉤刺8個(gè)，呈圓形排列。

(II)MorphologicalRecognition1.Imago.Thebodylengthis5~7mm,thewingspreadis15~18mm,andthebodyisdarkbrown.Theforewingsarelongandnarrow,darkbrownorrustybrown,with2smallblackdotsinthemidcellsand5smallblackdotsontheoutermarginofthewings.Thehindwingsarewideandlightgray,andthemarginalhairsarelong.2.Egg.Theeggisabout0.6mmlongandoval,withfinelongitudinalandtransverseridgesonthesurface.Itisgrayishwhiteatthebeginningofdeliveryandthenturnslightyellow,withsmallblackspotsatoneendnearthehatchingend.3.Larva.Whenmature,thebodylengthis18~20mm,andtheheadisslightlyflatanddarkbrown.Thepronotumisbrown,withdarkbrowninverted"splayed"linesonbothsides.Thebackofthe2ndsegmentfromthemesothoraxtotheabdomenisblack,andthesubsequentsegmentsaremilkywhite,withblacksubdorsallines.Thereisablacktwillonbothsidesofeachofthe2ndto6thabdominalsegments.4.Pupa.Thepupais7~8mmlong,spindle-shaped,andyellowish-brown.Ithasablunttipandfinehairsonthebody.Thereare8hookspinesattheendofthebuttockspine,whicharearrangedinacircularshape.三甘薯麥蛾綠色防控III.

GreenPreventionandControlofSweetPotatoLeaf-folder三甘薯麥蛾綠色防控III.

GreenPreventionandControlofSweetPotatoLeaf-folder（三）

發(fā)病規(guī)律我國(guó)從北到南1年發(fā)生3～9代。在北方以蛹在殘株落葉中越冬，而在南方以成蟲在甘薯枯葉下、雜草叢中以及屋內(nèi)陰暗處越冬。成蟲晝伏夜出，有趨光性，喜食花蜜。成蟲羽化后當(dāng)天即可交配，次日晚產(chǎn)卵。多產(chǎn)卵于葉脈之間，少數(shù)產(chǎn)卵在嫩芽、嫩莖上，每頭雌蟲平均產(chǎn)卵100多粒。初孵幼蟲在葉背啃食葉肉，2齡開(kāi)始吐絲卷葉，3齡后食量增加，一條幼蟲可卷食多片薯葉。4齡之后可將整葉對(duì)卷。食光葉肉或葉片．被害葉片大部分成灰色薄膜狀或斑枯狀，也有被食成較大孔洞的。田間幼蟲密度大時(shí)，成火燒狀團(tuán)塊。4齡之后的幼蟲行動(dòng)疾速活躍．觸之即跳躍逃離，此階段轉(zhuǎn)葉為害頻繁．一日當(dāng)中可轉(zhuǎn)葉3～6次。

(III)OccurrenceregularityThreetoninegenerationsoccurinayearfromnorthtosouthinChina.Inthenorth,itoverwintersaspupaeinstumpsandfallenleaves,whileinthesouth,itoverwintersasimagoesunderthedeadleavesofsweetpotatoes,inweedybushes,andintheshadowsofhouses.Theimagoesarenocturnalandphototaxisandliketoeatnectar.Theimagoescanmateonthesamedayaftereclosionandlayeggsthenextnight.Mosteggsarelaidbetweenveins,andafewlayeggsontenderbudsandstems.Eachfemalelaysmorethan100eggsonaverage.Thenewlyhatchedlarvaegnawonthemesophyllonthebackoftheleaves,spinandrolltheleavesatthesecondinstar,andincreasetheirappetiteafterthethirdinstar.Onelarvacanrollandeatmultiplepotatoleaves.Afterthefourthinstar,thewholeleavescanberolledinpairs.Eatingmesophyllorleaves.Mostofthedamagedleavesaregra