《昆虫病原线虫》PPT课件

第三节线虫杀虫剂,主要内容,一、昆虫病原线虫的形态特征二、线虫杀虫剂的发展历史三、昆虫病原线虫的种类及致病机理四、昆虫病原线虫的特点五、线虫杀虫剂的应用前景六、主要线虫杀虫剂产品,一、昆虫病原线虫的形态特征,线虫又称蠕虫，是一类较低等的动物，其体长仅毫米级大小，分类上属于无脊椎动物线虫动物门，线虫纲。已知的线虫约有42000多种。根据它们的食性可分为3类：腐生线虫、植物寄生线虫和动物寄生线虫。专性寄生在昆虫身体上的线虫，即虫生线虫，已知有1000多种。,一、昆虫病原线虫的形态特征,昆虫线虫：是寄生于昆虫体内的线虫，也称嗜虫线虫。可分为三类：寄生共生机械联合作用：调节昆虫种群和抑制害虫的作用,一、昆虫病原线虫的形态特征,身体半透明，呈细长的圆柱形，体表覆盖一层非细胞的弹性角质层，有横条纹或外环纹，但没有真的分节具排泄、神经、消化、生殖和肌肉系统，但无循环和呼吸系统消化道由位于前端的口、口腔、食道、肠、直肠等组成，肛门开口于腹面雌雄异体，行两性生殖寄主范围：多于3000种，分属31科，可寄生鳞翅、鞘翅、直翅、双翅、膜翅目等20目的数千种昆虫,二、线虫杀虫剂的发展历史,第一个有关线虫寄生昆虫的报道：18世纪中期1929粘Glaser从日本的一种丽金龟中得到了格氏斯氏线虫，标志利用昆虫病原线虫防治害虫的开始19401960年处于低潮19601970年，再次引人关注。如小卷蛾斯氏线虫、异小杆线虫,三、昆虫病原线虫的种类,已知的昆虫病原线虫有1000多种，其中应用较多的有：索线虫科斯氏线虫科异小杆线虫科,无尾感器纲Adenophorea咀刺目Enoplida索科Mermithidae四线科Tetradonematidae尾感器纲Secernentea尖尾目Oxyurida尖尾科Oxyuridae小杆目Rhabditida小杆科Rhabditidae双胃科Diplogasteridae头叶科Cephalobidae斯氏线虫科Steinernematidae异小杆科Heterorhabditidae垫刃目Tylenchida垫刃科Tylenchidae腊肠线虫科Allantonematidae新垫刃科Neotylenchidae滑刃科Aphelenchoididae园线虫科Sphaerulariidae,动物界KingdomAnimalia线虫门Nematoda(2纲13目),索科线虫(Mermithidae),形态：成虫幼虫体形相似，丝线状，体白色，0.230cm入侵过程：卵孵化出感染期索线虫主动寻找昆虫寄主，借口针和酶入昆虫体节间膜入侵。进入体腔后发育，一般游离于体腔内，有时达神经组织。症状：开始不表现明显病症，后行动迟钝、腹部异常膨大、食量减少或不取食。虫体异常透明，可从病虫外看到线虫寄主：昆虫、甲壳动物、蚯蚓、软体动物和蜘蛛等200种以上,索科(Mermithidae),索属(Mermis)：蝗虫水索属(Hydromermis)：摇蚊巴索属(Bathymermis)：水生昆虫湖索属(Limnomermis)：摇蚊无性索属(Agamermis)：蝗虫六索属(Hexamermis)：陆生昆虫对索属(Allomermis)：土壤昆虫腹索属(Gastromermis)：蚋两索属(Amphimermis)：稻螟、蛾类、蜻蜒泥索属(Psammomermis)：六月鳃角金龟兰索属(Lanceimermis)：水生昆虫里索属(Reesimermis)：各种蚊类细索属(Disimermis)：按蚊镒索属(Perutilimermis)：盐泽伊蚊新中索属(Neomesomermis)：蚋,FemaleMermis(索线虫属)quirindiensis,amermithidparasiteofgrasshoppersinAustralia,ovipositingonvegetationduringarainyperiod.(G.Baker),EggofMermisquirindiensis.(G.Baker),Habitatofmermithid(地丝虫属、索科)nematodesinNortheasternAustralia.(G.Baker),Coiledadultmermithidnematodesinsoil.(G.Baker),Thegrasshopper,Phaolacridiumvittatum,dissectedtoshowparasitismbymermithidnematode.(G.Baker),FemaleMermisnigrescens(蝗索线虫),amermithidparasiteofgrasshoppersinNorthAmerica.Theblackcolorofthemermithidnematodeistotheeggsinthefemalesbody.(J.Capinera),LocustdissectedtoshowMermisnigrescensjuvenilesinthecavity.(R.Gorden),LocustwithMermisnigrescenspostparasiteemergingfromtheregion.(J.Capinera),Japanesebeetle,Popilliajaponica,larvashowingmermithidjuvenilenematodeinsitu.(M.Klein),MermithidpostparasiteemergingfromJapanesebeetle,Popilliajaponica,larva.(M.Klein),UpperLeft:Terminalabdomenofblackflylarvawithmermithidjuvenileinsitu.LowerLeft:Mermithidpostparasiteemergingfromblackflylarva.UpperRight:Mermithidpostparasitesemergingfromblackflylarva.(R.Gordon),Romanomerisculicivorax(食蚊罗索线虫)juvenilecoiledinthethoraxofAedesaegypti.(R.Gordon),RomanomerisculicivoraxpostparasiteemergingfromthethoraxofAedesaegypti.(R.Gordon),垫刃目:园线虫科Sphaerulariidae,有3属通过生殖器伸进寄主体腔侵染能杀死寄主或使成虫不孕寄主：鞘翅目、双翅目、膜翅目等,垫刃目:园线虫科Sphaerulariidae,Sphaerulariopsisadult,anematodeparasiteofbarkbeetle,witheverteduterus.(DrawnbyR.Giblin-Davis),垫刃目:腊肠线虫科Allantonematidae,ContortotylenchusjuvenilesemergingfromIps(小蠹)adultbarkbeetle(树皮甲虫).(D.Kinn),小杆目：小杆科Rhabditidae,多营自由生活，许多种与昆虫发生各种类型的携带关系幼虫偶进入昆虫体腔，并在体腔内成熟交配，但大多雌虫不能在寄主体内产卵，寄主只在受到严重威胁时才死亡寄主：如天牛等,小杆目：小杆科Rhabditidae,Derocerasreticulum(fieldslug蛞蝓)feedingonaseedingofoilseedrape(canola).(M.Wilson),DerocerasreticulumintheforegroundinfectedbythenematodePhasmarhabditishermaphrodita.Notecharacter-isticswollenmantleoftheinfectedslugincomparisontothehealthyslugtheback-ground.(M.Wilson),DerocerasreticulumfivedaysafterdeathfollowinginfectedbyPhasmarhabditishermaphrodita,showingdenselypopulatedcadaverbeingfeduponbyadultnematodes.(M.Wilson),DerocerasreticulumonedayafterdeathfollowinginfectionbyPhasmarhabditishermaphrodita,showingadultnematodesspreadingandfeedingonentirecadaver,斯氏线虫科Steinernematidae,仅一个属，斯氏线虫属(Steinernemati)在生活史中形成特殊的“带鞘”的侵染期幼虫发育有两处阶段：寄生阶段和腐生阶段侵染期线虫体内携带共生细菌；昆虫发生败血病而死亡寄主：鞘翅目、双翅目、同翅目、膜翅目、等翅目、鳞翅目、脉翅目、蜻蜒目和直翅目,致病机理：昆虫病原线虫消化道内携带共生细菌，当线虫从昆虫消化道或体壁侵入，进入昆虫血腔后，共生菌从线虫体内释放出来，在昆虫血液内增殖，使寄主患败血症迅速死亡。,生活史：斯氏线虫科Steinernematidae异小杆科Heterorhabditidae,Themutualisticbacterium,Xenorhabdusbovienii,inavesicleofthenematode,Steinernemafeltiae(夜蛾斯氏线虫)(=bibionis).(R.Akhurst),StainedspecimenofSteinernemafeltiaeshowingthemutualisticbacterium,Xenorhabdusbovienii,inthevescle.(R.Akhurst),PhaseI(blue-green)andphaseII(pink)bacterialcoloniesofXenorhabdusnematophilus(嗜线虫致病杆菌)onNBTAplate.WhilephaseIbacterialcoloniesareblue-greeninthisslide,whencoloniesareactivelygrowingthiscolorwouldappeardarkgreeninstead(M.A.Hatab),CyclocephalahirtainfectedwiththenematodeHetero-rhabditisbacteriophor(redgrub)andhealthygrub(white).Theredcolorisduetopigmentproductionbysymbioticallyassociatedbacterium,Photor-habdusluminescens.(J.Clark),EncapsulatedSteinernemaglaseri(格氏斯氏线虫)shortlyafterpenetratingthroughthegutwallofthehousecricket.(Y.Wang),ncapsulatedSteinernemaglaseri(格氏斯氏线虫)shortlyafterpenetratingthroughthegutwallofthehousecricket.(Y.Wang),EncapsulatedSteinernemafeltiae(=bibionis)(斯氏属芜菁夜蛾线虫)juveniledissectedfromTipula(大蚊)obracea.(D.Gouge),Steinernemafeltiae(=bibionis)mating.(D.Gouge),Spodopteraexigua(非洲贪夜蛾)pupadissectedtoshowSteinernemacarpocapsae(小卷蛾斯氏线虫)juveniles.(A.Hara),Steinernemacarpocapsae(小卷蛾斯氏线虫)infectedjuvenileinatypicalrestingmodeinwater.NoteJshapedtail.(A.Hara),CommercialpreparationofSteinernemacarpocapsaeinawettabledispersiblegranule(WDG).(R.Georgis),Steinernemacarpocapsaeinfectedjuvenileencapsulatedincalciumalginate.Mostnematodesareinthecenterofthealginatecapsule.(H.Kaya),Crosssectionofawettabledispersiblegranule(WDG)withsteinernematidnematodesinthecenter.(R.Georgis),Diagramforproductionofwettabledispersiblegranules(WDG)containingentomopathogenicnematodes(e.g.steinernematids).(R.Georgis),异小杆科Heterorhabditidae,只有一属，异小杆属（Heterorhabditis)经消化道和气孔进入虫体。3-4天后雌雄同体的雌线虫产下幼虫，再过2天后幼虫发育成雌虫和雄虫交配后雌虫体内产卵，发育成第二期或侵染期线虫携带共生细菌，寄主由于细菌存在而死亡寄主：夜蛾科、象甲科、金龟科等,Galleria(蜡螟)larvainfectedwiththenematodeHeterorhabditisbacteriophor(嗜菌异小杆线虫),demon-stratingbioluminescenceinthedark.(R.Stuart),GallerialarvainfectedwiththenematodeHeterorhabditisbacteriophorinthelight.CompanionslideforSlide187.(R.Stuart),RosetteofHeterorhabditisbacteriophora(异小杆线虫).Commonphenomenonobservedwhenthisnematodeisstoredinwaterwherethenematodesaggregatearoundaparticle.Theaggregationcanbedispersedbytheadditionofweakcalciumcarbonate.(B.Jaffee),AntibioticproductionbyPhaseIPhotorhabdusluminescens(异小杆线虫消化道内的一种发光杆菌)showingclearzonepreventingthegrowthofBeauveriabassiana.Theotherp