斑痣悬茧蜂对不同龄期斜纹夜蛾幼虫的寄生功能反应

为评估斑痣悬茧蜂Meteorus pulchricornis(Wesmael)对其寄主斜纹夜蛾Spodoptera litura(Fabricius)幼虫的寄生作用,在室内研究了斑痣悬茧蜂对2、3和4龄斜纹夜蛾幼虫的寄生功能反应和搜寻效率。结果表明斑痣悬茧蜂对不同龄期斜纹夜蛾幼虫的寄生功能反应均符合HollingⅡ型模型的预测,对3龄寄主幼虫的攻击率大于对2龄寄主,对后者的攻击率又大于对4龄寄主幼虫的攻击;寄主处理时间随寄主龄期增大而延长。此外,斑痣悬茧蜂的搜寻效率随寄主密度增加逐渐降低,相同寄主密度下,斑痣悬茧蜂对2、3龄寄主幼虫的搜寻效率均高于对4龄寄主幼虫的搜寻。研究结果说明,斑痣悬茧蜂对斜纹夜蛾低龄幼虫的寄生作用大于对高龄幼虫的寄生。     

空间场所对斑痣悬茧蜂选择不同龄期甜菜夜蛾幼虫行为的影响

实验室条件下以甜菜夜蛾各龄期幼虫为寄主,在大观察罩内的盆栽植物上模拟低龄（1～2龄）和高龄幼虫（3～5龄）在田间的分布特点接虫,在小观察罩内同质空间内混合各龄幼虫,分别观察斑痣悬茧蜂的寄主选择行为。研究结果表明,空间大小对斑痣悬茧蜂选择寄主龄期的行为具有很大影响。在大观察罩中,斑痣悬茧蜂对甜菜夜蛾低龄幼虫（1～2龄）的遭遇和放弃行为比例均大于高龄（3～5龄）幼虫,而在小观察罩内的表现则相反。虽然斑痣悬茧蜂的寄主处理时间随寄主龄期的增大而延长,但在大观察罩内斑痣悬茧蜂花费的寄主处理时间比在小观察罩内长。在小观察罩内,寄生蜂对低龄幼虫的再次攻击间隔时间（653.17s）长于高龄幼虫（171.32s）,但在大观察罩内则相反。在大观察罩内低龄幼虫的被寄生率（23.24%～38.54%）高于小观察罩内（7.88%～21.43%）,但是小观察罩内高龄幼虫（4龄）的被寄生率（34.65%）大于大观察罩（16.86%）。最后,就空间大小影响斑痣悬茧蜂寄主选择行为的机理进行了探讨。     

Bt棉对斑痣悬茧蜂寄主选择及其子代发育的影响*

［目的］ 评价转Bt基因棉通过非靶标寄主斜纹夜蛾和甜菜夜蛾幼虫对寄生蜂的影响。［方法］ 分别采用选择性试验和非选择性方法,观察斑痣悬茧蜂对取食Bt棉叶和常规棉叶的斜纹夜蛾和甜菜夜蛾幼虫的产卵选择偏好,并观察子代蜂在不同处理幼虫体内的发育表现。［结果］ 取食Bt棉叶的斜纹夜蛾幼虫体重与取食常规棉叶的没有显著差异,而取食Bt棉叶的甜菜夜蛾幼虫体重显著小于取食常规棉叶。对斜纹夜蛾幼虫的选择性试验表明,斑痣悬茧蜂未表现出对取食Bt棉寄主幼虫的偏好。［结论］ 斑痣悬茧蜂子代的历期、存活以及羽化成蜂的体型大小等发育适应度特征,不受寄主幼虫所取食的食料植物的影响。     

斑痣悬茧蜂对感染细菌寄主的寄生选择和传播病菌作用

本研究旨在探究斑痣悬茧蜂是否寄生被短稳杆菌Empedobacter brevis感染的寄主,以及在寄生感病与健康寄主中是否传播病菌。在斜纹夜蛾幼虫为寄主的非选择性寄生试验中,将感染不同浓度短稳杆菌液及其感染后不同时间（1～5 d）的寄主分别供斑痣悬茧蜂寄生,结果表明,当细菌浓度较高时（5.0×107和1.25×107 cfu/mL）,寄生率随感染后间隔时间延长而具有较大波动（10%～20%）,当细菌浓度较低时（3.13×106 cfu/mL）,寄生率波动较小（10%～15%）,均表现二次曲线关系;但在对感染后不同时间寄主的选择性寄生试验中,当将感染细菌后1d分别与感染2、3、4或5d的寄主幼虫同时供斑痣悬茧蜂寄生时,斑痣悬茧蜂在感菌后1与3d、1与4d的寄主之间,偏好感菌后1d的寄主幼虫,寄生的寄主数量分别是感菌后3 d的2.5倍、4 d的2.0倍。在病菌传播试验中,分别以斜纹夜蛾和黏虫为寄主,结果表明,斑痣悬茧蜂寄生斜纹夜蛾幼虫后的传染率仅约5%;但寄生感菌黏虫寄主后能够传播病菌,而且传播概率随感染后时间的增加而下降,从起初的40%逐渐降至约10%。本研究结果说明,斑痣悬茧蜂对感染短稳杆菌寄主幼虫存在一定程度的寄生选择性,并通过寄生在一定程度上可传播该病菌。     

斑痣悬茧蜂对受药寄主幼虫的选择性及其后代表现

为探究受到杀虫剂亚致死影响的寄主幼虫对寄生蜂的寄主选择及其子代蜂的影响,以容性寄生蜂斑痣悬茧蜂Meteorus pulchricornis为研究对象,以氯氰菊酯亚致死浓度处理的甜菜夜蛾Spodoptera exigua4龄幼虫为寄主幼虫,进行非选择性和选择性试验。非选择性试验表明,斑痣悬茧蜂成功寄生（完成化蛹）的概率随受药寄主的体重增大而提高,而且受药寄主有效存活的概率亦随其体重增大而提高;与对照寄主相比,寄生蜂对受药寄主的寄生率降低60.2%、子代蜂发育历期显著延长、子代蜂体型（用后足胫节长度表示）显著增大。与来自对照寄主的子代蜂相比,来自受药寄主的子代蜂的寄生能力（用寄生率表示）未受影响,但其后代的结茧率降低10%、发育历期显著缩短、体型显著增大,说明羽化蜂的发育适合度得到了提高。选择性试验结果得出不一致的结论,根据对寄生蜂攻击次数的分析,未发现其在对照与受药寄主之间存在显著偏好;但根据第2次攻击的寄主识别期变量进行的风险分析,受药寄主被寄生风险显著低于对照寄主（低59.7%）,说明寄生蜂偏好攻击对照寄主幼虫。研究结果说明,斑痣悬茧蜂通过偏好体型较大的寄主幼虫,而减轻了受到杀虫剂亚致死效应的间接不良影响。结果表明该寄生蜂具有鉴别出接受亚致死杀虫剂不久的寄主幼虫的能力。     

寄生不同龄期草地贪夜蛾的斑痣悬茧蜂生长发育表现

草地贪夜蛾Spodoptera frugiperda(J. E. Smith),又称秋黏虫,是新入侵我国的外来物种。为探究本土天敌斑痣悬茧蜂寄生不同龄期草地贪夜蛾幼虫后的生长发育表现,本研究检测了斑痣悬茧蜂寄生2龄、3龄和4龄草地贪夜蛾幼虫后子代蜂幼虫发育历期、茧历期、羽化率、茧重、成蜂个体大小和成蜂寿命。结果表明,寄主龄期对子代蜂的幼虫发育历期、茧历期和成蜂寿命存在显著影响。与寄生4龄幼虫的子代蜂相比,寄生2龄和3龄幼虫的子代蜂幼虫发育历期分别平均延长了2.08 d(z=5.42,P0.05)和1.64 d(z=4.23,P0.05);寄生2龄幼虫的子代蜂茧历期平均延长了0.46 d(z=3.51,P0.05),但寄生4龄幼虫的子代蜂茧历期与寄生3龄幼虫的子代蜂茧历期无显著差异。4龄幼虫体内羽化的子代蜂成蜂寿命比在2龄和3龄幼虫体内羽化的子代蜂成蜂寿命分别平均延长了1.46 d(z=-2.60,P0.05)和1.68 d(z=-2.98,P0.05)。寄主龄期对子代蜂羽化率、茧重和成蜂个体大小无显著影响。随寄主龄期增大,子代蜂的发育速度加快,但寿命缩短。研究结果将为揭示斑痣悬茧蜂与寄主草地贪夜蛾的互作关系提供参考。     

卷叶螟绒茧蜂寄生棉大卷叶螟的行为及其与寄主密度的关系

卷叶螟绒茧蜂Apanteles derogatae Watanabe是棉大卷叶螟Sylepta derogata Fabricius幼虫期的一种重要内寄生蜂,对棉大卷叶螟种群有较好的控制作用。在实验室条件下,运用人工接虫观察法研究卷叶螟绒茧蜂对棉大卷叶螟幼虫的寄生行为。结果表明,该蜂搜寻寄主的时间平均为2．38 min,处理寄主的时间仅需0．86 min;寄生寄主的最适龄期为寄主2龄幼虫;对1龄幼虫的致死率达32%,但其寄生率仅为16%,其余16%的个体为穿刺致死。饲喂蜂蜜水能显著增加该蜂的产卵量,延长其产卵历期和增强其穿刺能力。寄生蜂的寄生能力与寄主密度的关系呈抛物线型:在寄生蜂均为16头/m~3雌蜂条件下,当寄主密度从80头/m~3增加到320头/m~3时,寄主的被寄生个体数随之增加,但当寄主密度超过320头/m~3后,寄主的被寄生个体数反而随寄主密度的上升呈下降趋势。     

寄生经历和寄主龄期对斑痣悬茧蜂寄生草地贪夜蛾幼虫效能的影响

草地贪夜蛾Spodoptera frugiperda(J.E.Smith)属鳞翅目灰翅夜蛾属,是新近入侵我国的重大危险性害虫。斑痣悬茧蜂已被证明对同属于灰翅夜蛾属的甜菜夜蛾和斜纹夜蛾的幼虫均具有较强的寄生能力。为探究短期驯化是否能有效改善斑痣悬茧蜂对草地贪夜蛾幼虫的寄生能力,本研究比较了有、无寄生经历的斑痣悬茧蜂雌蜂分别对2龄和3龄草地贪夜蛾幼虫在寄生行为和效能上的差异。结果表明,有寄生经历的雌蜂相对于无寄生经历的雌蜂能够较快刺扎寄主幼虫,并表现出更高的刺扎频率和寄生率,但雌蜂的各项行为指标在2龄和3龄幼虫间无显著差异。本研究将为改善本土天敌对入侵性草地贪夜蛾的防控能力提供借鉴。     

烟蚜茧蜂种内寄主识别与内部竞争

为明确寄生桃蚜Myzus persicae(Sulzer)的单性内寄生蜂烟蚜茧蜂Aphidius gifuensis Ashmead的种内识别与内部竞争,研究测定不同寄主密度对烟蚜茧蜂雌蜂卵的分布影响,以及不同产卵时间间隔对自身和同种寄主识别、种内内部竞争的影响。结果显示,烟蚜茧蜂在寄主密度为30头以下时,过寄生率高于31.16%;而寄主密度为50头以上时,过寄生率低于6.64%。在24 h以上的产卵时间间隔下,烟蚜茧蜂的自身过寄生率高于37.04%,而同种过寄生率在22.45%~25.93%之间;而且龄期较高的幼虫在种内内部竞争中获胜的概率高于72.00%。表明烟蚜茧蜂在低寄主密度下倾向于过寄生,在高寄主密度下有避免过寄生的趋势;烟蚜茧蜂倾向于自身过寄生,而对同种过寄生表现出一种产卵限制;在烟蚜茧蜂的种内内部竞争中,龄期较高的幼虫一般具有优势。     

甜菜夜蛾核多角体病毒对斑痣悬茧蜂发育及存活的影响

研究了甜菜夜蛾核多角体病毒对斑痣悬茧蜂Meteorus pulchricornis发育及存活的影响。正在蜕皮的甜菜夜蛾Spodoptera exigua 2龄幼虫被斑痣悬茧蜂寄生后,当其发育到3龄与4龄时分别饲以95%致死浓度(LC_(95))或10×LC_(95)甜菜夜蛾核多角体病毒(SpeiNPV),研究表明:甜菜夜蛾核多角体病毒对斑痣悬茧蜂发育及存活产生不利的影响,影响程度取决于寄生与饲毒的间隔期以及饲毒量。被寄生的甜菜夜蛾幼虫发育到第3龄(即被寄生后第1天,1dpp)分别饲以LC_(95)或10×LC_(95) SpeiNPV的处理,没有寄生蜂老熟幼虫从寄主体内钻出;被寄生的甜菜夜蛾幼虫发育到第4龄(4 dpp)分别饲以LC_(95)或10×LC_(95) SpeiNPV的处理,分别有25.62%与16.31%寄生蜂老熟幼虫从寄主体内钻出。甜菜夜蛾是否饲毒对寄生蜂的出蜂率、化蛹率及羽化率影响显著;饲毒浓度影响寄生蜂的出蜂率、化蛹率,但不影响羽化率。甜菜夜蛾饲毒与否对寄生蜂幼虫及蛹的发育历期无显著影响,但饲毒甜菜夜蛾体内寄生蜂幼虫、蛹及成蜂显著小于未饲毒的甜菜夜蛾体内寄生蜂幼虫、蛹及成蜂。     

瓜实蝇密度和蜂密度对印啮小蜂寄生效能的影响

在实验室内以瓜实蝇幼虫作寄主研究了寄主密度和蜂密度对印啮小蜂寄生效能的影响。结果表明：印啮小蜂对瓜实蝇的寄生量受寄主密度影响显著。寄主密度为5~20头/管时,寄主密度的增加对印啮小蜂的寄生效能有增强作用,而当寄主密度过高时,寄主密度的增加会使印啮小蜂的寄生效能降低。印啮小蜂个体之间存在相互干扰作用。平均每头雌蜂的寄生量和寄生率、每头雌蜂产仔蜂量随蜂密度的增加而减少,说明蜂密度的增加降低了印啮小蜂的寄生效能。当蜂密度从2头/管增加到15头/管时,平均每头雌蜂寄生的瓜实蝇数量降低了近3/4。蜂虫比例越低,子代的雌性比率越高。     

Differential effects of the acylurea insect growth regulator teflubenzuron on the adults of two endolarval parasitoids of Plutella xylostella,Cotesia plutellae and Diadegma semiclausum

The acylurea chitin synthesis inhibitor, teflubenzuron (‘Nomolt’® SC) showed no apparent activity against adult males of Diadegma semiclausum Hellén or Cotesia plutellae Kurdj. when applied to foliage at a rate ( = 50 g a.i. ha^?1) approximating to 2 × field usage. In contrast, the pyrethroid cypermethrin (‘Cymbush’® EC) showed appreciable foliar activity (at rates = 10–50 ga.i. ha^?1) to D. semiclausum but showed low activity against C. plutellae. When single adult female D. semiclausum were pre-treated with teflubenzuron (= 50 g a.i. ha^?1) and then exposed to 5. 10. 25, 50 or 100 second-instar host larvae, the number of purasitoid cocoons formed was significantly reduced compared with controls except at the lowest host density (P 0-05). However, there was no evidence that teflubenzuron had a host density-dependent effect on parasitism by D. semiclausum. Teflubenzuron had no significant effect on host parasitism in an equivalent experiment with C. plutellae (P > 0-05) except at the median host density. When batches of ten host larvae were introduced at hourly intervals to female D. semiclausum pre-treated with teflubenzuron (= 50 g a.i. ha^?1), the number of cocoons formed in the first two batches was not significantly different from untreated controls (P > 0-05), whereas teflubenzuron significantly reduced the number of cocoons in the next three batches of host larvae (P < 0-05). This suggests that teflubenzuron may affect chitin synthesis in developing eggs within female D. semiclausum but has little or no effect on pre-formed eggs which are more likely to be oviposited first. Teflubenzuron had no significant (P > 0-05) effect on parasitism by C. plutellae when presented with batches of host larvae. When female D. semiclausum and C. plutellae were placed in the same host arena, the former showed a 3-fold greater rate of parasitism. Pre-treatment with teflubenzuron significantly reduced parasitism by D. semiclausum (P > 0-05) but had no significant effect with C. plutellae (P > 0-05) although the latter species failed to exploit the reduction in parasitism by D. semiclausum. The differential response of D. semiclausum and C. plutellae to insecticides is discussed in relation to the relative rates of establishment of these species in Malaysia.     

荒漠啮齿类共存机制

自从“竞争排斥”理论被提出以来,生态相似物种在同一空间的共存机制一直是群落生物学研究中的焦点之一。关于这个问题的研究涉及许多不同类型的动物群落。本文综述了国内外相关荒漠啮齿群落物共存机制的研究。     

Valuation of gamma irradiation for proficient production of parasitoids (Hymenoptera: Chalcididae & Eucoilidae) in the management of the peach fruit-fly,Bactrocera zonata (Saunders)

Recognizing the potential significance of using nuclear techniques in biological control, investigations were conducted on the rearing of parasitoids of the peach fruit-fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae) to lead to a greater flexibility in the use of irradiated hosts. For improving mass production of the biological control agents, the use of irradiated fruit-fly larvae at the dose of 15 Gy proved useful for enhancing the parasitism and adult emergence of the larval parasitoid, Trybliographa daci (Weld) (Hymenoptera: Eucoilidae) due to no negative repercussions on parasitoid development. Overall, parasitism by the parasitoid increased with age of the host larvae; however, significantly higher parasitism occurred on 4 d-old irradiated larvae of B. zonata compared to those aged 5 d. The female parasitoids preferred the irradiated larvae, and significantly higher numbers of larvae were parasitized compared with non-irradiated larvae. There was no significant difference in adult parasitoid emergence with respect to the sex of the host. A radiation level of 80 Gy was the best dose for rearing of the pupal parasitoid, Dirhinus giffardii (Silvestri) (Hymenoptera: Chalcididae) owing to broad tolerances in the use of irradiation for the rearing of fruit-fly's parasitoids. Percentage parasitism by D. giffardii varied with host pupal age, and the preference of the female parasitoid was lower on 48 h old host pharate pupae due to optimum size and mass of host. Present findings further revealed that the 24 h old host pupae of B. zonata were relatively more suitable for the maximum parasitism and progeny production of D. giffardii. Parasitisms by D. giffardii and T. daci were significantly higher on B. zonata host when parasitoids were released at a density of 3000 individuals per acre (7500 per hectares) than the other release rates of parasitoids for the management of fruit-flies in mango orchards. The implementation of these findings ought to help improve the mass production of parasitoids and the effectiveness of releases of biocontrol agents for control of B. zonata in mango plantations.     

密度对双斑截尾寄蝇寄生草地螟的影响

双斑截尾寄蝇Nemorilla maculosa是草地螟优势寄生性天敌之一。本文研究了寄主密度和数量对寄蝇寄生草地螟高龄幼虫的影响。研究结果表明：双斑截尾寄蝇与草地螟幼虫在1：5～1：25五种不同的益害比时,双斑截尾寄蝇对草地螟幼虫的寄生数随寄主密度增加而增大,其中l：15时达到最高值（9．8±0．6头）,与其他处理差异显著;而寄生率随寄主密度继续增大而减小,当两者的比例增加到1：25时,草地螟幼虫的被寄生率仅为25．3％,显著低于1：5处理的84．0％。双斑截尾寄蝇与草地螟幼虫益害比相同时（1：10）,寄蝇寄生率随草地螟和寄蝇密度的增加而增大,在相同空间下达到5：50时,寄蝇的寄生率为最高,达66．4％。     

草地贪夜蛾幼虫日龄及取食的食物对淡足侧沟茧蜂寄生效果的影响

为评估淡足侧沟茧蜂对草地贪夜蛾的防控效果,在室内环境条件下,研究了草地贪夜蛾幼虫寄主日龄和所取食食物对淡足侧沟茧蜂寄生效果的影响。结果表明,无论草地贪夜蛾幼虫取食人工饲料或玉米叶片,淡足侧沟茧蜂对3日龄和5日龄寄主幼虫的寄生率、结茧率、出蜂率及对寄主致死率均显著高于8日龄寄主。另外,在同日龄情况下,淡足侧沟茧蜂对取食玉米寄主的寄生率、结茧率以及子代出蜂率均高于寄生于取食人工饲料的幼虫上的相关指标。寄主取食不同食物会影响淡足侧沟茧蜂的寄生效果,且淡足侧沟茧蜂对5日龄草地贪夜蛾幼虫寄生效果较好。本结果可为室内条件下利用草地贪夜蛾幼虫扩繁淡足侧沟茧蜂,以及应用淡足侧沟茧蜂对草地贪夜蛾进行田间防控提供理论依据。     

一种测试鳞翅目幼虫嗅觉行为的高效选择装置

昆虫的寄主定位、产卵选择、聚集、求偶等行为受到来自昆虫周围环境的挥发性气味化合物的影响和调控。研究挥发物对昆虫行为的影响作用主要采用Y形嗅觉仪等行为检测装置,而研究挥发物对鳞翅目幼虫的影响作用却缺乏专业、高效的装置。本研究设计制作了研究鳞翅目幼虫行为的高效选择装置,适用于高效筛选对鳞翅目幼虫具有引诱、驱避等作用的挥发物。小菜蛾3龄幼虫的行为选择测试结果表明,对小菜蛾幼虫引诱最强的植物为大白菜,其次是油菜和甘蓝;花生叶片对小菜蛾幼虫没有作用;而番茄叶片对小菜蛾幼虫则具有驱避作用。由此说明该装置可以有效测定小菜蛾幼虫对不同挥发物的反应,将为挥发物对昆虫行为的影响研究、进而筛选新的化合物来控制虫害提供新的技术支持。     

Impact of neem and chinaberry fruit extracts on the pest/parasitoid (Pieris rapae/Hyposoter ebeninus) interactions

A new technique was performed to simulate exposure of the host Pieris rapae larvae to both botanical treatment and the parasitoid Hyposoter eheninus in different sequences. It was found that: host larvae subjected to both parasitoid and 1% neem treatment showed significant or insignificant reductions both in pupal formation as well as adult emergence percentages when treatment preceded or followed parasitism, respectively. Both neem treatments revealed significant prolongation in the development of unparasitized and parasitized larvae (on average 4 to 5 days delay), whereas chinaberry caused significant prolongation only among parasitized larvae (on average 2.7 days delay in egg-larval duration). Fate of parasitism among untreated hosts was found to be faster than among neem-treated ones. Parasitism percentages among 1 and 0.5% neem-treated third instar host larvae held 7 days before parasitism reached 3 and 2 times that achieved among those reared on untreated diet for the same period, ­respectively.It was concluded that prolongation of the preferred target instars of the host, due to neem treatments, increased the chance for parasitism. Nevertheless, treatment with neem at the LC₅₀ level exhibited a great reduction in parasitoid progeny. However, a lower concentration (LC₂₅) could reasonably potentiate parasitism without drastic losses in parasitoid emergence.     

桔小实蝇寄生蜂一中国新记录种印度实蝇姬小蜂Aceratoneuromyia indica（Silvestri）及其寄生效能研究

在中国首次发现并记述了桔小实蝇寄生蜂印度实蝇姬小蜂Aceratoneuromyia indica（Silvestri）,该蜂隶属膜翅目姬小蜂科啮小蜂亚科。研究标本保存于广东省农业科学院植物保护研究所。同时在温度25℃、RH75%、光周期L：D=16h：8h的条件下,研究了印度实蝇姬小蜂对桔小实蝇幼虫的寄生功能反应。结果表明：桔小实蝇幼虫的密度变化对印度实蝇姬小蜂的寄生作用有很大影响,可用功能反应HollingⅡ模型模拟,其模拟方程为Na=0.2528N0/（1＋ 0.0090N0）。通过该方程可明确一头印度实蝇姬小蜂在24h内最多可寄生28.24头桔小实蝇幼虫;其寄生一头寄主幼虫所需的时间为0.85h。印度实蝇姬小蜂成虫的自身密度对寄生也有干扰作用,其干扰作用符合Hassell-Varley模型,拟合方程为a=0.0556P^-0.2427。