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。     

Evaluation of Sensitivity to Phoxim and Cypermethrin in an Endoparasitoid,Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae), and Its Parasitization Efficiency Under Insecticide Stress

Insecticides can have consequences for beneficial arthropods. Insect parasitoids can contact insecticides through direct exposure spray droplets or residues on crop foliage. Here, we focus on better understand the response of Meteorus pulchricornis (Wesmael), a parasitoid wasp of lepidopteran pests, and its detoxification mechanisms on stress caused by phoxim and cypermethrin. Hence, we determined the dose–mortality curves and estimating the sublethal concentrations (LC₃₀ and LC₅₀). Then, we applied the sublethal concentrations against adult parasitoids to assess its survival, parasitism efficacy, and also developmental and morphometric parameters of their offspring. Simultaneously, we check the activities of glutathione S-transferase (GST), acetylcholinesterase (AChE), and peroxidase (POD) after sublethal exposure of both insecticides, which has measured until 48 h after treatment. Overall, phoxim and cypermethrin exhibited acute lethal activity toward the parasitoid with LC₅₀ values 4.608 and 8.570 mg/liter, respectively. Also, we detect that LC₃₀ was able to trigger the enzymatic activity of GST, AChE, and POD, suggesting a potential detoxification mechanism. However, even when subjected to sublethal exposure, our results indicate strong negatives effects, in particular for phoxim, which has affected the parasitism efficacy and also the developmental and morphometric parameters of M. pulchricornis offspring. Therefore, it can be concluded that both phoxim and cypermethrin have negative impacts on M. pulchricornis and we suggest cautioning their use and the need for semifield and field assessments to confirm such an impact.     

甲氧基丙烯酸酯类和三唑类杀菌剂对斑痣悬茧蜂的毒性

为明确甲氧基丙烯酸酯类(嘧菌酯、醚菌酯、肟菌酯)和三唑类(粉唑醇、腈菌唑、戊唑醇、己唑醇及戊菌唑)杀菌剂对寄生性天敌斑痣悬茧蜂Meteorus pulchricornis的毒性风险,在室内分别采用药膜法和摄入法测定了上述8种杀菌剂对斑痣悬茧蜂存活的影响。结果表明,处理方法对结果有明显影响。在药膜法处理中,肟菌酯表现出最高的触杀毒性,其致死中时间(LT50值)为1.18d;戊菌唑次之,其LT50值为1.98d;粉唑醇的毒性最低,LT50值长达52.58d。在摄入法处理中,供试杀菌剂的LT50值均大于15d。除粉唑醇药膜处理和己唑醇摄入处理外,其余处理斑痣悬茧蜂的寿命均显著缩短。因此,在实际生产中应关注甲氧基丙烯酸酯类和三唑类杀菌剂,尤其是肟菌酯和戊菌唑对斑痣悬茧蜂等寄生蜂天敌的安全性。     

取食不同种类的糖对斑痣悬茧蜂寿命、繁殖力及营养贮存的影响

寄生蜂成虫可以直接取食含有单糖和二糖的花蜜和蜜露。本文研究了取食葡萄糖、果糖、麦芽糖和甘露糖对斑痣悬茧蜂寿命、繁殖力和营养贮存的影响。结果显示，取食葡萄糖、果糖、麦芽糖和甘露糖后，斑痣悬茧蜂的寿命分别为25.9、21.3、21.5和11.1 d，与对照相比显著增加；平均后代数分别为72.8、51.1、55.8和8.6头，而清水对照只有4.3头，其中取食甘露糖后，斑痣悬茧蜂平均后代数与对照差异不显著。体内主要物质含量测定表明取食糖类后，寄生蜂极大程度地积累总糖，取食葡萄糖、果糖和麦芽糖与水相比寄生蜂体内脂含量显著增加，并随着处理时间延长而增加。但取食甘露糖与水相比寄生蜂体内脂含量显著下降。取食4种糖都在产卵高峰前期蛋白质浓度达到最高，死亡前蛋白质浓度最低，两者之间差异显著。     

斑痣悬茧蜂和斜纹夜蛾核多角体病毒的互作及氟啶脲对寄生蜂的影响

为探寻小同生物防治资源协同控制害虫的可行性,研究了斑痣悬茧蜂和斜纹夜蛾核多角体病毒(SIN-PV)联合作用于斜纹夜蛾时两者的相互影响,以及昆虫生长调节剂氟啶脲对斑痣悬茧蜂的影响,结果表明,在SIN-PV浓度为10~6PIB/ml、10~7PIB/ml和10~8 PIB/ml 3个浓度下,无沦是病毒和寄生蜂一同处理,还是先寄牛蜂处理1 d后冉病毒处理,斑痣悬茧蜂对SINPV的侵染力和侵染速度均无显著影响.联合处理时病毒埘寄牛蜂也无不良影响,蜂后代结茧数与对照无差异,仅缩短了先寄生蜂后10~6PJB/mJ SINPV处理组寄生蜂从卵刮茧的发育历期.从氟啶脲对斑痣悬茧蜂的影响来看,寄生蜂寄生经1.25 mg/L氟啶脲处理后的甜菜夜蛾,其后代发育历期和结茧均未受影响,仅羽化受影响.寄生蜂成虫卣接经10 ms/L、20 mg/L和40 mg/L(田间推荐剂量)氟啶脲处理后,均对后代结茧和发育历期等无显著影响.表明斑痣悬茧蜂可较安全地与一定浓度范围斜纹夜蛾核多角体病毒或氟啶脲联合用于夜蛾类害虫的控制.     

营养和寄主密度对斑痣悬茧蜂搜寻行为的影响

以斜纹夜蛾Spodoptera litura幼虫为寄主,观察了不同补充营养处理（饥饿、饲喂清水、饲喂30%糖水）和寄主密度等因素对斑痣悬茧蜂Meteorus pulchricornis的搜寻效率和寄生选择行为的影响。结果显示,不同寄主密度对斑痣悬茧蜂的搜寻效率和选择偏好有显著影响,寄生蜂明显倾向于选择高密度寄主斑块。未发现补充营养显著影响斑痣悬茧蜂的搜寻时间,说明补充营养对斑痣悬茧蜂的搜寻效率没有显著影响,但对其寄生的寄主数量具有显著影响,在5头.叶-1与15头.叶-1的寄主斑块之间具有显著差异。     

斑痔悬茧蜂对甜菜夜蛾幼虫龄期的选择及其生长发育的研究

在室内采用非选择性和选择性试验，研究了斑痣悬茧蜂（Meteorus pulchricornis）对不同龄期甜菜夜蛾（Spodoptera exigua）幼虫的选择以及后代的生长发育表现。在非选择性试验中，斑痣悬茧蜂虽然寄生所有1-5龄幼虫，但寄生率不同，对2-4龄幼虫的寄生率（〉70％）显著高于对1龄（53％）和5龄（20％）幼虫的寄生；寄生不同龄期寄主幼虫的后代寄生蜂生长发育表现亦存在差异，寄生2-4龄寄主幼虫的寄生蜂结茧化蛹率（〉95％）和羽化率（〉90％）高于寄生1龄和5龄幼虫的，而发育历期短于寄生1龄和5龄幼虫的；但后代寄生蜂成虫的体型（用后足胫节长度表示）随寄主幼虫龄期增长而逐渐增大。由此表明，甜菜夜蛾2-4龄幼虫对斑痣悬茧蜂的生长发育适合度表现更有利。在成对选择试验中，当5龄幼虫不在供选寄主组合中时，斑痣悬茧蜂喜好龄期较大的寄主幼虫，即最喜好4龄幼虫，最不喜好1龄幼虫；在4龄与5龄幼虫之间倾向于选择4龄幼虫，这与非选择性试验得出的结论基本一致。     

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。     

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。     

The autumn leafroller: Phenology,damage and parasitoids in a Dutch apple orchard

The phenology of the autumn leafroller,Syndemis musculana, a local pest of apple, was studied in order to forecast larval emergence. From 1983–1986, peak flight as determined with sexpheromone traps was always between 13–18 May. The duration of embryonic development was determined at various constant temperatures and used to estimate the periods of egg hatch in these four years. Each year, most eggs should have hatched in the second decade of June.Differences in attack rates between apple cultivars seem to be explained largely by the variation in picking time. Larvae are only half grown at the beginning of harvest (cv. James Grieve), and have gone into hibernation when the latest variety (cv. Golden Delicious) is picked. Moreover, the varieties Cox's Orange Pippin and Belle de Boskoop, picked about half time, are liable to receive additional damage by caterpillars brought with the picked fruits into storage.Various hymenopterous parasites were reared from caterpillars. As the only leafroller in the orchard which hibernates as mature larva,S. musculana may promote winter survival of some parasitoids, like the eulophidColpyclypeus florus.Samenvatting De fenologie van de herfstbladroller (Syndemis musculana Hübner), een incidentele plaag op appel, werd nader bepaald met het doel het uitkomen van de eieren te kunnen voorspellen. In 1983–1986 viel de piekvlucht, bepaald met behulp van feromoonvallen, steeds tussen 13 en 18 mei.De ontwikkelingsduur van de eieren bij verschillende constante temperaturen werd gebruikt om de periode van uitkomen te schatten. De meeste eieren zullen ieder jaar in de eerste helft van juni uitkomen.Geconstateerde verschillen in schade tussen appelrassen blijken goeddeels terug te voeren op verschillen in pluktijdstip. De rupsen van de herfstbladroller zijn pas half-was als de eerste appels eind augustus geplukt worden, terwijl tegen het einde van de oogst begin oktober de meeste al in winterslaap zijn. Met name tussentijdse rassen, als Cox's Orange Pippin and Schone van Boskoop, lopen extra schade op doordat grotere rupsen met de geplukte vruchten in de kist terecht komen.Uit de rupsen werden negen, al van andere boomgaardbladrollers bekende, sluipwespen gekweekt, Omdat deze bladrollersoort, als enige in de boomgaard, als volgroeide rups overwintert, lijkt zij bij uitstek geschikt als winterwaard.This study was carried out at the Experimental Orchard De Schuilenburg, Schuilenburg 3, 4041 BK Kesteren, the Netherlands, to which address correspondence should be addressed.