烟粉虱及温室白粉虱为害后对后续粉虱种群的影响

【目的】分析烟粉虱Bemisia tabaci(Gennadius)或温室白粉虱Trialeurodes vaporariorum(Westwood)为害番茄后对后续温室白粉虱和烟粉虱生长、发育、成虫寿命和繁殖等产生的促进或抑制作用,可为明确寄主植物番茄介导的温室白粉虱-烟粉虱的种间互作,开展粉虱的科学防控提供科学依据。【方法】通过在寄主植物番茄叶片上先将B型烟粉虱或温室白粉虱按不同的顺序、时间间隔分开接种,再系统观察后续接上的两种粉虱生长、发育、繁殖等种群参数的变化。【结果】(1)先期接上烟粉虱对后续温室白粉虱的发育、寿命、产卵量有明显的促进作用;这种作用需烟粉虱的持续诱导,若去掉烟粉虱,其对温室白粉虱的促进作用即消失;先期接上温室白粉虱可缩短后续烟粉虱伪蛹期,但温室白粉虱的持续存在不利于烟粉虱的产卵,且明显降低烟粉虱的内禀增长率和净增殖率。(2)先后在番茄上同时接上温室白粉虱可降低后续烟粉虱的单雌产卵量和雌、雄虫的成虫寿命;先后同时接种烟粉虱却显著地增加了温室白粉虱的单雌产卵量;烟粉虱的提前存在降低了后续烟粉虱单雌产卵量。(3)但两种粉虱之间作用存在着一定的时间滞后性。烟粉虱对温室白粉虱的发育、寿命、产卵量产生的促进作用大约在其卵期后的一段时间才能显现出来;温室白粉虱对烟粉虱伪蛹期的缩短作用也需提前诱导;而温室白粉虱对温室白粉虱的促进作用相当滞后,直到成虫期才显现出来。【结论】B型烟粉虱和温室白粉虱之间可通过寄主番茄产生相互影响,前期烟粉虱为害可显著促进后续温室白粉虱卵和若虫的发育,而前期温室白粉虱为害对烟粉虱的发育不利。     

ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株上烟粉虱寄主适应性及寄主植物营养成分含量和防御反应变化

【目的】本研究以番茄褪绿病毒(tomato chlorosis virus, ToCV)和番茄黄化曲叶病毒(tomato yellow leaf curl virus, TYLCV)为主体,旨在明确ToCV单独侵染及TYLCV&ToCV复合侵染对烟粉虱Bemisia tabaci MED隐种寄主适应性的影响,并从寄主植物营养成分和防御角度解析不同番茄病毒侵染对烟粉虱MED隐种寄主适应性影响的生理机制。【方法】ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株后,统计分析番茄植株上烟粉虱MED隐种成虫存活率和产卵量以及番茄植株中氨基酸和总糖含量;通过RT-qPCR技术检测番茄植株茉莉酸(JA)信号通路关键基因(FAD7和PI II)以及水杨酸(SA)信号通路关键基因(NPR1和PR1)的表达模式。【结果】相对于取食健康番茄植株的烟粉虱成虫,取食番茄病毒侵染的番茄植株烟粉虱MED隐种成虫的存活率和产卵量均显著降低,其中以TYLCV&ToCV复合侵染番茄植株为寄主时,烟粉虱MED隐种成虫的存活率和产卵量均达到最低水平。TYLCV&ToCV复合侵染后,番茄植株中总氨基酸含量、14种水解氨基酸含量以及总糖含量低于ToCV单独侵染番茄植株。ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株后,FAD7和PI II的表达量均显著降低,并且2个基因在TYLCV&ToCV复合侵染植株中的表达水平最低;然而,NPR1和PR1的表达水平在ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株中均有上升趋势,TYLCV&ToCV复合侵染番茄植株中NPR1表达水平和ToCV单独侵染番茄植株中PR1表达水平均显著高于健康番茄植株中的。【结论】ToCV单独侵染和TYLCV&ToCV复合侵染均能够明显降低番茄植株上烟粉虱MED隐种的寄主适应性,且TYLCV&ToCV复合侵染更不利于烟粉虱MED隐种生存;相对于健康番茄植株,ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株营养成分与防御系统发生了变化且存在差异。研究结果为揭示烟粉虱与植物病毒互作提供了参考。     

新疆地区烟粉虱生物型的区域分布及其携带的番茄黄化曲叶病毒检测

【目的】明确不同烟粉虱Bemisia tabaci (Gennadius)生物型在新疆地区的区域分布及其携带番茄黄化曲叶病毒的情况。【方法】本文利用烟粉虱mtDNA COⅠ基因片段作标记以及番茄黄化曲叶病毒(tomato yellow leaf curl virus, TYLCV)特异性引物, 鉴定新疆不同地区烟粉虱生物型, 并检测其携带TYLCV情况。【结果】石河子市、 博乐市、 岳普湖县、 泽普县、 叶城县、 莎车县、 墨玉县、 和田市与和田县烟粉虱属于B型烟粉虱, 且720 bp COⅠ基因序列一致性为100%; 阿克苏市、 哈密市、 鄯善县、 乌鲁木齐市、 克拉玛依市与伊宁市烟粉虱属于Q型烟粉虱, 720 bp COⅠ基因序列一致性为99.9%~100%; 吐鲁番市与库尔勒市兼有B型烟粉虱和Q型烟粉虱。伊宁市、 乌鲁木齐市、 鄯善县、 哈密市、 阿克苏市、 库尔勒市、 莎车县、 和田县和墨玉县的烟粉虱样本携带TYLCV, 除2011年底已经暴发危害的莎车县外, 其他区域均为番茄黄化曲叶病毒病发生的高风险区域。【结论】本研究为新疆地区烟粉虱及番茄黄化曲叶病毒病的科学防控提供依据。     

下调烟粉虱MED隐种BtabCSP6表达对番茄黄化曲叶病毒传播的影响

【目的】番茄黄化曲叶病毒(tomato yellow leaf curl virus, TYLCV)是对农业生产造成威胁的主要病毒之一,自然条件下通过媒介昆虫烟粉虱Bemisia tabaci传播。已有研究表明烟粉虱雌成虫比雄成虫具有更强的获毒与传毒能力。本研究旨在探明烟粉虱化学感受蛋白(chemosensory protein, CSP)基因BtabCSP6表达对病毒传播的影响,为控制病毒发生寻找新途径。【方法】使用TYLCV侵染性克隆方法获得带毒番茄植株,微虫笼收集不带毒烟粉虱MED隐种成虫固定在感染TYLCV的番茄植株叶片获毒48 h;利用RT-qPCR技术测定分别取食感染和未感染TYLCV番茄植株的烟粉虱MED隐种雌雄成虫体内BtabCSP1-8基因表达量变化;通过饲喂法利用RNAi对烟粉虱MED隐种雌成虫BtabCSP6基因进行干扰48 h后饲喂TYLCV感染的番茄植株,测定烟粉虱MED隐种雌成虫的获毒率和传毒率。【结果】RT-qPCR检测结果表明,与未侵染的烟粉虱MED隐种雌成虫相比,侵染TYLCV的雌成虫体内BtabCSP3和BtabCSP6基因的表达量变化最为显著。同样地,在侵染TYLCV的雄成虫体内,BtabCSP4和BtabCSP6表达量的变化最为明显。饲喂dsBtabCSP6 48 h后,烟粉虱MED隐种雌成虫体内BtabCSP6表达量降低;取食感染TYLCV番茄植株不同时间烟粉虱MED隐种雌成虫的获毒率和不同数量雌成虫对未感染TYLCV的番茄植株的传毒率与对照相比均显著降低。【结论】下调烟粉虱MED隐种雌成虫体内BtabCSP6基因的表达,可显著降低烟粉虱MED隐种雌成虫的获毒率和传毒率,说明BtabCSP6可能影响TYLCV传播。     

烟粉虱及海氏桨角蚜小蜂对中国番茄黄化曲叶病毒感染烟草的嗅觉反应

双生病毒可通过调控寄主植物促进媒介昆虫烟粉虱种群增长,然而病毒侵染植物后是否通过调控植物挥发物来影响烟粉虱及其天敌的嗅觉反应还未见报道。【目的】本文旨在研究烟草植株感染中国番茄黄化曲叶病毒(Tomato yellow leaf curl China virus,TYLCCNV)后对烟粉虱Bemisia tabaci(Gennadius)及其重要寄生性天敌海氏桨角蚜小蜂Eretmocerus hayati(Zolnerowich and Rose)嗅觉反应行为的影响。【方法】利用Y形嗅觉仪方法,我们测试了烟粉虱及海氏桨角蚜小蜂对带毒植株、健康植株及烟粉虱危害植株的选择偏好性。【结果】烟粉虱及海氏桨角蚜小蜂选择携带TYLCCNV病毒的烟草显著多于健康烟草植株,但烟草被病毒与烟粉虱共同侵染时,烟粉虱对带毒烟草的选择仍显著多于无毒植株,而寄生蜂虽然仍较多选择带毒植株,但无显著差异。【结论】这些结果表明烟粉虱及海氏桨角蚜小蜂偏好选择携带TYLCCNV病毒的烟草,但这种偏好作用在烟粉虱取食共同危害时有一定程度的减弱。本研究首次报道了双生病毒侵染植物可增加烟粉虱及其天敌对植物的选择作用,并就其功能及机制进行了讨论。     

喷施吲哚-3-乙酸 (IAA) 对番茄及其上B型烟粉虱的影响

【目的】不同植物生长调节物质对植食性昆虫产卵、发育、取食等常有促进或抑制作用,进而影响植物与昆虫的互作关系。本研究旨在阐明常用的植物生长调节剂吲哚-3-乙酸对B型烟粉虱Bemisia tabaci (Gennadius)的影响,进而探索防治烟粉虱环境友好的方法,同时期望获得更加优质的烟粉虱用作替代寄主饲养寄生蜂。【方法】对番茄 Solanum lycopersicum L.植株外源喷施吲哚-3-乙酸(IAA),检测其生理生化的响应;记录B型烟粉虱存活率、产卵量并测量解毒酶等指标。【结果】喷施IAA后番茄叶片含水量略有上升,叶面积增大,叶绿素含量增加,过氧化物酶(POD)活性降低,多酚氧化酶(PPO)活性升高,超氧化物歧化酶(SOD)活性变化不显著(P＞0.05)。喷施IAA后番茄上B型烟粉虱成虫存活率高于对照组,其中50 mg/L IAA番茄上B型烟粉虱成虫存活率和总产卵量最高,250 mg/L IAA存活率最低;喷施IAA 120 h后烟粉虱总产卵量升高;碱性磷酸酶(AKP)、超氧化物歧化酶(SOD)活性较对照升高。【结论】喷施不同浓度的IAA溶液后,番茄植株的生理生化水平发生不同程度的改变,烟粉虱成虫的存活状况、产卵量以及体内解毒活性也会产生不同程度的改变。适宜剂量的IAA处理能够使烟粉虱的生存表现更加优异,从而为饲养寄生蜂提供优质的替代寄主。     

漆酶-1基因在烟粉虱MEAM1隐种和温室粉虱中的表达模式比较

【目的】漆酶-1(LAC1)在粉虱-植物互作中发挥重要作用,本研究旨在探讨烟粉虱Bemisia tabaci MEAM1隐种和温室粉虱Trialeurodes vaporariorum两种存在竞争关系的粉虱中LAC1基因表达模式是否存在差异。【方法】测定烟粉虱MEAM1隐种和温室粉虱唾液漆酶-1活力;对温室粉虱LAC1基因进行了克隆和测序;通过荧光定量PCR测定和比较了LAC1在两种粉虱不同发育阶段和成虫不同组织中的表达谱以及取食外施水杨酸(0. 5 mmol/L)的番茄植株后两种粉虱不同发育阶段和成虫不同组织中LAC1的表达水平,同时检测了成虫存活率和产卵量。【结果】酶活力测定结果表明两种粉虱的唾液中漆酶-1活力差异不显著。温室粉虱PCR扩增后得到大小639 bp的LAC1基因中间片段。发育表达谱结果表明,LAC1基因在两种粉虱各个发育阶段均有表达,在烟粉虱MEAM1隐种成虫期表达量逐渐升高,而在温室粉虱各发育时期的表达量无显著差异;烟粉虱MEAM1隐种成虫期LAC1的表达量高于温室粉虱。组织表达结果表明,LAC1在两种粉虱成虫的头胸部、中肠和腹部残骸中均有表达,但在中肠中丰度最高。取食外施水杨酸番茄植株的烟粉虱MEAM1隐种,随取食时间的延长成虫存活率下降,与对照(取食喷施清水的植株)相比差异显著。羽化后14 d时,取食外施水杨酸植株的烟粉虱MEAM1隐种存活率仅为对照的一半,而取食外施水杨酸植株的温室粉虱的存活率与对照相比差异不显著。无论是取食外施水杨酸的植株还是取食对照植株,烟粉虱MEAM1隐种体内LAC1表达量和产卵量均高于温室粉虱。【结论】LAC1在两种粉虱体内表达模式存在差异,这可能在两种粉虱的竞争适应中具有一定作用。     

番茄褪绿病毒TaqMan荧光定量PCR快速检测方法的建立与应用

【目的】本研究旨在建立TaqMan实时荧光定量PCR(TaqMan RT-qPCR)技术,快速检测单头烟粉虱Bemisia tabaci体内的番茄褪绿病毒(tomato chlorosis virus,ToCV)。【方法】根据ToCV外壳蛋白保守序列设计了1对特异性引物和1条TaqMan探针,建立了TaqMan RT-qPCR方法;与常规PCR检测进行比较,检测该方法的灵敏度与特异性;并应用该方法对单头烟粉虱成虫体内ToCV进行了快速检测。【结果】本研究构建的TaqMan RT-qPCR检测ToCV的标准曲线,其循环阈值(Ct值)与模板浓度具有良好的线性关系,扩增效率为98%。该方法对ToCV的最低检测浓度为8.3×10 copies/μL,灵敏度是常规RT-PCR的1000倍。该方法与田间番茄两种重要病毒番茄黄化曲叶病毒(tomato yellow leaf curl virus,TYLCV)和番茄斑萎病毒(tomato spotted wilt virus,TSWV)检测无交叉反应。单头烟粉虱成虫ToCV检测结果表明,温室内ToCV侵染植株上烟粉虱携毒率为100%,田间烟粉虱的携毒率为30%。【结论】本研究建立的TaqMan RT-qPCR检测方法,可快速有效检测单头烟粉虱体内ToCV携毒情况,为该病毒病的防控提供了技术支撑。     

烟草品种和温度对B型烟粉虱和温室白粉虱生物学参数的影响

在室内20℃、26℃和30℃三个设定温度条件下,研究了CF-965、NC-89和NC-82三个烟草品种对B型烟粉虱和温室白粉虱生长发育和繁殖的影响.结果表明:26℃时两种粉虱在CF-965、NC-89和NC-82三个烟草品种上的发育历期没有明显差异,但温室白粉虱卵期和若虫期的发育历期较烟粉虱依次分别延长了1.32d、2.81d和 2.04d.在CF-965上,B型烟粉虱卵期和若虫期的总存活率和平均单雌产卵量分别为54.19%和55.17粒,温室白粉虱仅分别为31.99%和39.17粒;在NC-89上,B型烟粉虱卵期和若虫期的总存活率和平均单雌产卵量分别为23.47%和37.50粒,温室白粉虱仅分别为15.75%和17.25粒;两种粉虱在NC-82上卵期和若虫期的总存活率和平均单雌产卵量差异不大,表明B型烟粉虱对CF-965和NC-89的适应能力较温室白粉虱强.两种粉虱在20℃时的发育历期最长,32℃时最短,26℃时居中.20°C时烟粉虱卵期和若虫期的存活率20.96%为最低,26℃和32℃时分别达54.19% 和53.29%;而温室白粉虱在32℃条件下存活率11.66%为最低,20℃和 26℃时分别达31 34% 和31.99%.温室白粉虱在20℃时产卵量大于烟粉虱, 在26℃时的产卵量小于烟粉虱,30℃时则不能产卵,但烟粉虱成虫30℃时的产卵量仍可达21.06粒.由此说明烟粉虱在较高温度条件下的适应能力显著强于温室白粉虱.山东烟区烟草生长中期的田间平均温度多在22～30℃,适合B型烟粉虱的发生,应引起高度重视.     

辽宁省冬季温室内越冬粉虱伪蛹的种类鉴定及烟粉虱体内番茄黄化曲叶病毒的检测

为了揭示辽宁省冬季温室内越冬粉虱伪蛹的种类及烟粉虱Bemisia tabaci （Gennadius）携带番茄黄化曲叶病毒（tomato yellow leaf curl virus, TYLCV）情况, 于2012年1月份在辽宁省不同县市区的温室作物上采集了17份粉虱伪蛹样品（每样品含30头粉虱伪蛹） , 镜检鉴别粉虱种类并利用mtCOI基因对烟粉虱生物型进行了鉴定; 检测了烟粉虱携带TYLCV情况并对其PCR扩增产物进行了测序分析。结 果表明： 辽宁省冬季温室内存在越冬温室白粉虱Trialeurodes vaporariorum （Westwood）与烟粉虱。17份粉虱样品中, 11份样品为烟 粉虱样品, 6份样品为温室白粉虱和烟粉虱混合样品。混合样品中, 温室白粉虱仅在锦州凌海（LH）样品中占优势。17份烟粉虱样品（包 括混合样品）中, 仅有4份样品为B型与Q型混合样品, 其他13份样品烟粉虱生物型均为Q型。17份烟粉虱样品中有3份Q型烟粉虱样品检测 到TYLCV, 系统树分析进一步证实该病毒是TYLCV。调查结果为辽宁省粉虱与TYLCV的早期测报和防控提供了科学依据。     

Genetic Analysis of Bemisia (Hemiptera: Aleyrodidae) Populations by Isoelectric Focusing Electrophoresis

Twenty-one whitefly populations in the genus Bemisia were evaluated for genetic variation at 3 allozyme loci. Nine of the 22 populations that exhibited polymorphic loci were subjected to allozyme analysis using a minimum of 10 enzymes, representing 10 to 14 distinct loci. Among those nine variants examined, calculated genetic distances ranged between 0.03 and 0.52, with three main groups emerging from the analysis. One group comprised two closely related Western Hemisphere variants of B. tabaci: type A from California, United States and a geographically proximal population from Culiacan, Mexico. A second cluster contained five collections previously identified as B. tabaci type B and Bemisia argentifolii, while a third group contained a single population from Benin, Africa. The latter two groups were grouped separately from New World populations and are thought to have a recent origin in the Eastern Hemisphere.     

保护地间作芹菜对温室粉虱的防治作用

温室白粉虱Trialeurodes vaporariorum(Westwood)和烟粉虱Bemisia tabaci(Gennadius)是严重危害葫芦科、茄科和豆科等多种蔬菜的主要害虫,具有分布范围广、种群数量大、繁殖力强等特性。作者通过田间试验研究了蔬菜保护地内间作温室粉虱非嗜食植物芹菜(Apium graveliens L.)对其的防治效果。结果表明:与空白处理和常规化学防治相比,在番茄和黄瓜保护地内间作芹菜对温室粉虱均具有显著的防治效果,驱避效果分别达到98.0%和84.5%。这些结果是初步的,但其为进一步研究温室粉虱的寄主选择机制和非化学防治方法提供了依据。     

Digestive, salivary, and reproductive organs of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) B type

A microscopic analysis of the morphology and ultrastructure of the digestive, salivary, and reproductive systems of adult Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) B type was conducted using light, scanning, and transmission electron microscopy. The internal anatomy of B. tabaci was found to be similar to that reported for Trialeurodes vaporariorum. In a microscopic analysis of the salivary glands, we have shown that each primary salivary gland is composed of at least 13 cells varying in morphology and staining differentially, while the accessory salivary glands are composed of four morphologically similar cells. We analyzed the course of the alimentary canal in B. tabaci, demonstrated the internal morphology of the organs, and clarified the location of the filter chamber relative to other organs in the whitefly. Our observations confirm that the pair of structures extending from the connecting chamber are caeca that may aid in fluid movement through the midgut and are not Malpighian tubules, as previously suggested. We confirm an earlier finding that the whitefly lacks Malpighian tubules, having instead specialized Malpighian-like cells within the filter chamber at the juncture with the internal ileum. Finally, we provide the first scanning electron microscopic analysis showing the reproductive organs of B. tabaci. Our investigation provides clarified terminology for several components of the digestive and excretory system. We also provide drawings and micrographs that will aid future researchers in localizing the internal organs of B. tabaci. We expect our analysis to provide a valuable tool for studying B. tabaci / plant virus interactions and physiological and biological aspects of this insect.     

伊朗粉虱寄生蜂种类记述(膜翅目:广腹细蜂科、姬小蜂科、蚜小蜂科)

本文报道了伊朗寄生粉虱的25种寄生蜂,分别隶属于膜翅目的广腹细蜂科、姬小蜂科和蚜小蜂科,其中15种寄生蜂种类为伊朗的分布新纪录(标有*号者)。     

Dispersal of the broad mite,Polyphagotarsonemus latus (Banks) (Heterostigmata: Tarsonemidae), by the greenhouse whitefly,Trialeurodes vaporariorum (Westwood) (Homoptera: Aleyrodidae)

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood), (Homoptera: Aleyrodidae) was found to disperse the broad mite, Polyphagotarsonemus latus (Banks) (Heterostigmata: Tarsonemidae). Mite presence on whiteflies was highly aggregated. This is the second whitefly species reported to disperse the broad mite, suggesting some recognition of the insects by P. latus.     

Genetic diversity of Iberian populations of Bemisia tabaci (Hemiptera: Aleyrodidae) based on random amplified polymorphic DNA-polymerase chain reaction

The genetic structure of six Iberian populations of the whitefly Bemisia tabaci, two of them biotype Q, one biotype B, and the other three a mixture of both, has been studied using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). A total of 336 individuals was completely discriminated by means of 234 scored bands. Separate analyses of molecular variance of haploid males and diploid females using the pairwise number of differences between haplotypes showed that biotypes contribute significantly more to the observed variability than populations within biotypes. On average, gene flow between two biotypes of the same population is lower than between populations of identical biotypes. On the basis of these results and the nondetection under natural conditions of a single hybrid, we consider that both biotypes are genetically isolated under the ecological conditions prevailing in the south Iberian Peninsula. All populations of biotype Q presented similar values of intrapopulational diversity, which were higher than the values shown by populations of biotype B.     

一种适合于烟粉虱产卵的新型人工膜系统

介绍一种适合烟粉虱Bemisia tabaci(Gennadius)产卵的新型人工膜系统。该系统由一个透明的塑料盒,底直径30mm,顶口直径40mm,深35mm,其上覆盖1层或2层Parafilm M膜,与产卵的成虫相接触的1层厚度为5~8μm,2层膜中间或单层膜上加试验所需的试剂。将膜装置放于不透光的容器上,其上覆盖黄色玻璃纸,以吸引烟粉虱产卵。该装置可用于烟粉虱的人工产卵,观察卵的发育及研究相关的生理机制。     

Biocoenology and control of whiteflies in sericulture

Abstract The damage caused by the whiteflies Dialeuropora decempuncta (Quaintance & Baker, 1913), Aleurodicus dispersus Russell, and Aleuroclava sp. to mulberry plants is extensive and they cause a huge economic loss to mulberry leaves which affects silkworm rearing. Dialeuropora decempuncta is a major pest in western Bengal, whereas spiralling whitefly A. dispersus has been reported to attack mulberry plants in South India. The whiteflies are present throughout the year in south India, with high populations in summer (March—June) and low ones in winter (October—January). The population is positively correlated with temperature and negatively correlated with humidity. Chemical control is the quick solution to minimize the pest population. However, the indiscriminate and large-scale use of highly poisonous synthetic chemical pesticides has resulted in ecological imbalance, in addition to their toxic effects on living organisms, including human beings. Hence there is a need for developing methods and materials within an eco-friendly atmosphere. Previous investigations indicate that neem-based insecticides may be a suitable alternative for pest management in sericulture. Use of neem products in sericultural pest control has many merits. It will also help in the successful introduction of biological controls in India. Several exotic parasitoids have been found to be highly effective, including two aphelinid parasitoids Encarsia haitiensis Dozier and E. meritoria Gahan. These are most promising and are reported to minimize the fly pest population. The parasitization potential and behaviour of the parasitoids have to be carefully assessed before they are introduced to control fly pest populations. There is a need for careful assessment of all these advanced biological technologies in order to develop a profitable, safe and durable approach for whitefly control in sericulture.