甜菜夜蛾的饲养方法介绍

介绍一种甜菜夜蛾的室内饲养方法 ,采用本方法累代饲养甜菜夜蛾 8代 ,平均蛹重达 1 1 2 .9mg ,平均化蛹率 97% ,平均羽化率为 91 .3% ,室内饲养结果表明 ,该饲养方法可用于室内大量饲养甜菜夜蛾     

甜菜夜蛾抗药性研究现状

就有关甜菜夜蛾Spodoptera exigua(Hbner)对常用杀虫剂的抗药性现状作综述。甜菜夜蛾对拟除虫菊酯类、有机磷类、氨基甲酸酯类杀虫剂已产生了较高水平的抗药性,其中山东泰安抗性种群对氯氟氰菊酯的抗性高达2445.5倍;对多杀菌素等生物杀虫剂产生了中低水平的抗性;对昆虫生长调节剂如虫酰肼的敏感性也有所降低,但昆虫生长调节剂依然是比较理想的防治药剂。对交互抗性及抗性治理也作了阐述。     

Efficacy of Spodoptera exigua multiple nucleopolyhedrovirus as a biological insecticide for beet armyworm control in greenhouses of southern Spain

Chemical control measures targeted at Spodoptera exigua in greenhouse sweet pepper crops in Spain have resulted in pest resistance to virtually all commercially available insecticidal products. A multicapsid nucleopolyhedrovirus (SeMNPV), isolated from diseased S. exigua in Spain, was produced in laboratory reared larvae, tested for insecticidal activity in a laboratory bioassay, and was then applied in eleven commercial greenhouses planted with sweet pepper. Virus occlusion bodies (OBs) were applied on two occasions, at an interval of ～7 days, at a rate of 5×10⁸ OBs/L of spray in a volume of ～600 L/ha, depending on crop phenology and greenhouse area. The percentage of plants showing recent (<48 h old) feeding damage fell dramatically in greenhouses with high infestations of S. exigua; the same pattern was observed, although less dramatically, in greenhouses with low infestations. Average mortality of larvae collected from treated plants at 4 days after each application, and reared in the laboratory until death, was high (70–89%) and was not significantly affected by the degree of crop infestation. In a separate trial, the rate of acquisition of infection was examined in larvae that fed on plants treated with 1×10⁸ or 5×10⁸ OBs/L of spray. Of the 27 and 60% of larvae, respectively, that acquired infection in the 48 h period after spraying, about half became infected in the first 6 h post-application, irrespective of application rate. Acquisition of infection proceeded more slowly during the night-time compared to the daytime period, underlining the advantages of early morning applications of the virus. We conclude that the Spanish SeMNPV isolate merits registration as a biological insecticide for use in greenhouse crops in this region.     

甜菜夜蛾在四种寄主植物上的生命表参数比较研究

在控制条件下对甜菜夜蛾Spodoptera exigua(Hübner)在白菜、大葱、甘蓝和豇豆上的生命表参数进行了比较研究。结果表明,甜菜夜蛾幼虫在4种寄主植物上均为5个龄期。幼虫和蛹在大葱上的发育历期最长,在白菜上最短。甘蓝叶片饲养的甜菜夜蛾生殖力最高,单雌产卵量为1015.8粒,豇豆叶片上饲养的生殖力最低,为496.1粒。甜菜夜蛾在甘蓝上的内禀增长率和净增殖率最高,分别为0.237和287.82,在大葱上最低,分别为0.172和173.90。在大葱上甜菜夜蛾幼虫存活率较低,在其他3种寄主植物上较高。甜菜夜蛾的特定年龄生殖率在甘蓝叶片上最高,第22天单雌产卵量高达453.6粒。研究结果表明,在选取的4种植物中,甘蓝是甜菜夜蛾的最适寄主。     

甜菜夜蛾类钙粘蛋白基因全长cDNA的克隆及序列分析

昆虫中肠膜上的类钙粘蛋白(cadherin-like protein)是Bt毒素的一类重要受体,它与Bt毒素对昆虫的杀虫作用机制以及昆虫对Bt毒素的抗性等密切相关。本研究根据已报道的其它昆虫的类钙粘蛋白基因的保守区设计简并引物,应用RT-PCR和RACE技术克隆了迁飞性重要害虫甜菜夜蛾Spodoptera exigua(Hübner)类钙粘蛋白基因全长cDNA序列(命名为SeCAD,GenBank登录号为HQ647122),全长5582bp,编码1739个氨基酸,推导的氨基酸序列包括1个信号肽、1个前蛋白区、11个钙粘蛋白重复、1个近膜区、1个跨膜区和1个胞质区。预测的分子量和等电点分别为196.447ku和4.47。该蛋白与同科的大螟Sesamia inferens、蛀茎夜蛾S.nonagrioides、烟芽夜蛾Heliothi svirescens、烟夜蛾Helicover paassulta亲缘关系更近,氨基酸序列一致性分别为61.28%、60.34%、60.14%、60.08%。这些结果对于揭示转Bt基因作物对非靶标、迁飞性甜菜夜蛾的杀虫作用机制以及评价其潜在的对Bt毒素抗性机制等奠定了基础。     

氰氟虫腙亚致死剂量对甜菜夜蛾生长发育和繁殖力的影响

本文研究了氰氟虫腙的亚致死剂量LC15(28.423μg/mL)和LC25(41.363μg/mL)对甜菜夜蛾Spodoptera exigua(Hübner)亲代和子1代的一些生物学特性的影响。结果表明:LC15和LC25处理组与对照组相比,甜菜夜蛾亲代的化蛹率,羽化率和单雌产卵量分别降低了49.3%,60.0%;♀(12.65%,25.09%)和♂(13.14%,28.91%);25.6%,65.7%,畸形蛹率分别提高了10.5%,14.4%。子1代的化蛹率,羽化率和单雌产卵量分别降低了11.8%,24.6%;♀(9.48%,21.54%)和♂(11.61%,24.08%);14.4%,54.3%,畸形蛹率分别提高了4.1%,5.8%。另外子1代的孵化率、幼虫的存活率降低,蛹期和成虫期缩短,产卵前期延长,产卵期显著缩短。总体来说,LC15和LC25剂量的氰氟虫腙对甜菜夜蛾亲代与子1代的生物特性都有不同程度的影响,并且LC25剂量对甜菜夜蛾的影响要比LC15剂量大。     

甜菜夜蛾性信息素的研究与应用

甜菜夜蛾Spodoptera exigua(Hbner)已成为我国的重要农业害虫,其高抗药性和危害具有隐蔽性,致使防治十分困难。文章介绍甜菜夜蛾性信息素的主要成分、活性、配比、诱芯剂型、诱捕器类型和利用性信息素监测、防治甜菜夜蛾技术的研究概况。认为改进现有技术后并应用于实际,将会更有效地监测和防治甜菜夜蛾的发生与危害。     

交配和温度对甜菜夜蛾(Spodoptera exigua)雌蛾性信息素产生的影响

研究表明,交配对甜菜夜蛾雌蛾性信息素各组分的滴度,比例及其在个体间的变异均无显著的影响,因此交配不影响雌蛾在下一暗期的再次求和交配,环境温度对甜菜夜蛾性信息素的产生则有显著的影响,15－25℃最有利于甜菜夜蛾性信息素的产生,而10℃低温和35℃主温则使信息素产生受到明显影响,其中以10℃低温的影响更甚。10℃低温不仅使各组分的滴度产生显著改变,而且使二元性信息素组分的比例受到显著影响,并使二元组分通讯信息的个体间变异明显增大（CV＞10％）,这些改变必半扰乱甜菜夜蛾雌雄间的正常交配。     

寄主植物对甜菜夜蛾三龄幼虫抗寒力的影响

寄主植物是影响昆虫抗寒性的主要因子之一。研究了不同温度下甜菜夜蛾Spodoptera exigua(Hübner)3龄幼虫取食小白菜、甘蓝、葱和菠菜后,对过冷却能力和体内冷冻保护剂的影响。结果表明,寄主植物对甜菜夜蛾3龄幼虫的过冷却能力有显著性影响,其中以取食甘蓝的幼虫过冷却点最低。温度和寄主植物对其过冷却点、结冰点和虫体含水量有明显的交互作用。寄主植物对其体内的海藻糖含量有显著性影响,而对甘油和糖原含量没有显著性影响。温度和寄主植物仅对海藻糖含量有显著的交互作用。随着温度的升高,取食不同寄主的幼虫体内海藻糖和糖原含量的变化趋势完全相反,认为海藻糖是由糖原转化而来。研究结果提示冬季合适的寄主植物有利于甜菜夜蛾低龄幼虫越冬。     

Genetic effects on flight capacity in the beet armyworm,Spodoptera exigua (Lep., Noctuidae)

The beet armyworm, Spodoptera exigua, is an important migratory insect pest in tropical and subtropical regions worldwide. The current study investigated genetic variation in the flight capacity of both female and male moths, using a quantitative genetics approach. The offspring–parent regression showed that parents had a significant influence on the flight duration of offspring, and the heritability estimated as 0.302. The upward selection increased mean flight duration from 123.7 to 284.6 min in females and from 113.9 to 254.0 min in males during 8 h of flight test; by contrast, downward selection decreased it from 123.7 to 65.6 min in females and from 113.9 to 29.8 min in males, while it did not change significantly in either females or males of the control line over eight generations. The mean realized heritability was estimated as 0.432 based on upward selection but 0.130 on downward selection, suggesting the asymmetry of response to selection on flight capacity. Reciprocal crosses between the two selected lines confirmed the dominance of ‘long‐flying genes’ in the inheritance of flight capacity. A positive genetic correlation was found between increased flight duration and pupal weight. The presence of such additive genetic variance and covariance for flight capacity and the fitness trait, pupal weight, in the population of S. exigua may have underpinned the evolution of its migratory behaviour.     

甜菜夜蛾不同龄期幼虫对药剂的敏感性及其与酶活力的关系

【目的】明确甜菜夜蛾Spodoptera exigua(Hübner)不同龄期幼虫对甲氨基阿维菌素苯甲酸盐和毒死蜱的敏感性及其与羧酸酯酶、多功能氧化酶、谷胱甘肽S-转移酶和乙酰胆碱酯酶活性的相关性。【方法】采用室内生物测定方法检测甜菜夜蛾不同龄期幼虫对药剂的敏感性,并检测了不同龄期幼虫体内羧酸酯酶、多功能氧化酶、谷胱甘肽S-转移酶和乙酰胆碱酯酶的活力。【结果】在所测定的5个龄期中,随龄期增加,敏感性逐渐降低,其中1~5龄幼虫对甲氨基阿维菌素苯甲酸盐的LC50分别为0.1010、0.3561、0.7568、1.4325和8.4390 mg/L,对毒死蜱的LC50分别为27.4632、46.8495、87.5222、129.3217和1 356.6770 mg/L。单头幼虫的羧酸酯酶、多功能氧化酶、谷胱甘肽S-转移酶和乙酰胆碱酯酶活力随虫龄的增加而提高,与龄期间对药剂的敏感性呈负相关(由于外源化合物摄入量减少,5龄单头幼虫的多功能氧化酶活力略有降低)。【结论】甜菜夜蛾不同龄期幼虫对药剂的敏感性存在非常明显的差异,在田间防治中,应选择对杀虫剂敏感性较高的低龄幼虫作为最佳防治时期。     

甜菜夜蛾防控技术研究与示范——公益性行业(农业)科研专项“甜菜夜蛾防控技术研究与示范”研究进展

针对当前我国蔬菜生产中甜菜夜蛾Spodoptera exigua(Hübner)高抗药性、猖獗为害、防控困难的现状,项目组对甜菜夜蛾的发生规律、越冬与迁飞、抗药性、生物防治与综合防控等进行了系统的研究。明确了甜菜夜蛾在我国各地的发生规律及发生动态,从南到北发生时间呈楔形,而发生量总体东高西低,从南到北呈中部高南北低的马鞍形。阐述了甜菜夜蛾"无卵子发生-飞行拮抗"的迁飞特性,提出了接力棒式季节性南北往返迁飞模式,初步阐明了甜菜夜蛾在我国东部地区的迁飞路线与迁飞时间。提出并认证了甜菜夜蛾在我国的越冬区域。明确了全国各主要发生区甜菜夜蛾对10种杀虫剂的抗药性水平,探明了甜菜夜蛾对茚虫威、甲氨基阿维菌素苯甲酸盐的抗性风险、交互抗性、种群适合度、抗性遗传规律和抗性机理,提出了抗药性治理措施。分别在海南、湖南、湖北、上海、天津等地进行了甜菜夜蛾田间药效试验,筛选出环境友好型高效杀虫剂7种。掌握了马尼拉陡胸茧蜂、夜蛾黑卵蜂和淡足侧沟茧蜂人工大量繁殖技术,改进了甜菜夜蛾核型多角体病毒生产工艺,解决了寄生蜂和病毒规模化生产及田间释放关键技术,达到规模化生产的要求。改进优化了甜菜夜蛾性引诱剂配方、研发出新型诱捕装置,并投入生产应用。集成出4套农业生产轻简化实用技术,华南、华中、华北、华东地区根据当地发生特点制定了4套防控方案。在全国甜菜夜蛾主要发生区建立试验基地16个,核心示范基地29个,年示范面积总计约3800hm2,取得显著的经济、社会和生态效益。     

我国甜菜夜蛾间歇性暴发频度的大尺度地理差异及其成因分析

【目的】为探索我国甜菜夜蛾Spodoptera exigua(Hübner)间歇性大暴发频度的大尺度地理差异及其成因,作者研究和分析了我国1956—2008年52年间共发生的121次甜菜夜蛾大暴发频次地理分布的行政区域特征、纬度特征和经度特征。【方法】首先查阅和整理我国历代以来有关甜菜夜蛾记载和研究的文献,并按时间序列方式进行归纳和总结,得出中国1956—2008年52年间共发生甜菜夜蛾大暴发频次为121年次,然后分别按中国省级行政区域、纬度分级区域和经度分级区域进行重新整理分析,在此基础上,进一步细分出中国不同省区及不同经纬度地区甜菜夜蛾有暴发记录的历年总频次数,然后进行统计分析。【结果】分析结果表明:按省级行政区域进行统计,中国有17省(直辖市)有甜菜夜蛾暴发的记录;按暴发频次多少可分为低频暴发区(记录1~4次的共有8省市,即天津1、北京1、海南1、湖南1、云南2、广西3、辽宁3、福建3)、中频暴发区(记录5~9次的共有5省市,即湖北5、安徽7、上海8、江西8、陕西8,占总频次的29.8%)和高频暴发区(记录10次以上的4省市,即山东10、河南13、浙江13、江苏34,占总频次的58%)。按经纬度值进行统计,中国甜菜夜蛾有暴发记录的纬度范围为21.44°~41.97°N,即从中国南部的福建莆田至北部的辽宁抚顺都有甜菜夜蛾暴发的记录,经度范围为107.09°~123.97°E,即从中国西部的陕西关中至东部的辽宁抚顺都有甜菜夜蛾暴发的记录。而暴发最频繁的纬度范围是28°~38°N,约占总频次的89.3%;暴发最频繁的经度范围是113°~121°E,约占总频次的81.8%。【结论】中国甜菜夜蛾间歇性暴发区以华北平原和长江中下游平原地区为主,暴发寄主以蔬菜和棉花为主,暴发季节以7—10月为主。甜菜夜蛾间歇性高频暴发区,其地理特征主要为低海拔地区,即平均海拔低于500 m(也有极少部分发生在平均海拔为1 000~2 000 m之间的盆地);其气候特征主要为暖温带3 400℃≤活动积温≤4 500℃及亚热带地区4 500℃≤活动积温≤8 000℃、湿润(年降水量≥800 mm)及半湿润地区(400≤年降水量≤800 mm)和亚热带及温带季风气候区(该两个气候区的共同特点是夏季高温多雨,冬季低温少雨或寒冷干燥)。     

Response of multiple generations of beet armyworm,Spodoptera exigua (Hübner), feeding on transgenic Bt cotton

Development, reproduction and food utilization of three successive generations of beet armyworm, Spodoptera exigua (Hübner), fed on transgenic and non‐transgenic Bt cotton were examined. Significantly longer larval life‐span and lower pupal weight were observed in three successive generations of S. exigua fed on transgenic Bt cotton compared with non‐transgenic Bt cotton. Significantly higher survival rate and adult fecundity of S. exigua were found in three successive generations of S. exigua fed on transgenic Bt cotton compared with non‐transgenic Bt cotton. The survival rate and adult fecundity of S. exigua were occurred significant increase in the third generation compared with the first generation after feeding on transgenic Bt cotton. Significantly lower consumption, frass and relative growth rate (RGR) were observed in three successive generations of S. exigua fed on transgenic Bt cotton compared with non‐transgenic Bt cotton. Cotton variety significantly affected all indices of larval consumption and utilization in three successive generations of S. exigua, except for efficiency of conversion of ingested food. However, beet armyworm generation only significantly affected RGR of S. exigua. The results of this study indicated food quality on the diet‐utilization efficiency of S. exigua was different along with beet armyworm generation. Measuring multigenerational development and food utilization of S. exigua at individual and population level in response to Bacillus thuringiensis (Bt) can provide a more meaningful evaluation of long‐term population dynamics than experiments on a single generation. It is imperative to develop an appropriate multigenerational pest management tactic to monitor the field population dynamics of non‐target pests (e.g., beet armyworm) in agricultural Bt cotton ecosystem.     

Interaction between MbMNPV and the braconid parasitoid Habrobracon hebetor (Hym., Braconidae) on larvae of beet armyworm,Spodoptera exigua (Lep., Noctuidae)

The survival of a braconid parasitoid Habrobracon hebetor was investigated on nucleopolyhedrovirus (NPV)-infected Spodoptera exigua larvae. The second-instar larvae were exposed to 30, 51.4 and 180 PIB/mm² of Mamestra brassicae NPV (MbMNPV) as under-LD₅₀, LD₅₀ and over-LD₅₀ values, respectively. They were accessible to be parasitized by H. hebetor after 24, 48 and 72 h post-treatment. Infection of the larvae with MbNPV was deleterious to the survival and parasitism of H. hebetor. The survival of H. hebetor in MbNPV-infected S. exigua larvae was dependent on the interval between viral infection and parasitization, as well as on the treatment dose of MbMNPV; very few adults of parasitoid emerged from infected hosts when host larvae were exposed to 180 PIB/mm² of MbNPV on 72-h interval treatment. The inoculation dose of MbNPV and the timing of parasitoid release had significant effect on the development of H. hebetor on virus-infected hosts. Field applications of virus for biocontrol of S. exigua may lead to substantial mortality of immature parasitoids.     

甜菜夜蛾cDNA文库的构建

以甜菜夜蛾Spodoptera exigua(Hübner)幼虫为材料建立了cDNA表达文库,经检测文库的初始滴度为1.1×105pfu/mL,重组率为97%,扩增后文库的滴度为5.4×107pfu/mL。用设计的2对引物筛选该文库,得到468 bp的1个片段,分析后证实是几丁质合成酶基因I保守区域的1个片段。该cDNA文库为进一步筛选甜菜夜蛾功能基因奠定了基础。     

Flight activity of three Spodoptera spp., Spodoptera litura, S. exigua and S. depravata, measured by flight actograph

Flight activities of three Spodoptera species were measured by the aid of flight actograph: S. litura and S. exuiga being regarded as long‐distance migratory insects, and S. depravata being non‐migratory and diapause‐inducible species. In all species tested, flight activities were observed only in scotophase, males showed far higher activities than females, being several times higher at the time of maximum flight activity, which was observed within 2 days after adult eclosion. Total flight activity in males was highest in S. litura, some being flyable even 12 days after eclosion, followed by S. exigua being one‐third compared to the former species, while in S. depravata flight activity was nearly half of that of the second species and most ceased to fly within a week after eclosion. There occurred species‐specific daily rhythms in flight activity during respective scotophase. In S. litura, both females and males exhibited a peak of flight activity shortly after light‐off and exhibited the second flight activity in late scotophase, the females slightly but the males more actively compared to early scotophase. In S. exigua, both sexes did not respond to light‐off, did not show a peak of flight activity in early scotophase, whereas males, but not females prominently increased activity toward the end of scotophase. In S. depravata, both sexes exhibited a peak of flight activity in early scotophase, and the males revived flight activity, being maximum shortly before light‐on, but the females did not show a clear rhythm in flight activity. These features observed in flight activity were discussed in relation with migratory capability.     

Role of a small G protein Ras in cellular immune response of the beet armyworm, Spodoptera exigua

Insect cellular immune responses accompany cytoskeletal rearrangement of hemocytes to exhibit filopodial and pseudopodial extension of their cytoplasm. Small G proteins are postulated to be implicated in the hemocyte cellular processes to perform phagocytosis, nodulation, and encapsulation behaviors. A small G protein ras gene (Se-Ras) was cloned from cDNAs prepared from hemocytes of the beet armyworm, Spodoptera exigua. The open reading frame of Se-Ras encoded 179 amino acids with a predicted molecular weight of 20.0 kDa, in which 114 residues at amino terminus were predicted to be a GTP binding domain. It showed high sequence similarities (86.1-92.8%) with known ras genes in other insects. Se-Ras was constitutively expressed in all developmental stages from egg to adult without any significant change in expression levels in response to bacterial challenge. A specific double strand RNA (dsRNA) could knockdown its expression in the hemocytes after 48 h post-injection. While the RNA interference (RNAi) did not show any change in total or differential hemocyte counts, it impaired hemocyte behaviors. The RNAi of Se-Ras significantly suppressed hemocyte spreading, cytoskeleton extension, and nodulation behaviors in response to bacterial challenge. Release of prophenoloxidase from oenocytoids was significantly inhibited by the RNAi, which resulted in significant suppression in PO activation in response to an inducer, PGE₂. These results suggest that Se-Ras is implicated in mediating cellular processes of S. exigua hemocytes. This is the first report of Ras role in insect cellular immune response.     

Transgenic expression of Dendrolimus kikuchii nucleopolyhedrovirus enhancin in tobacco enhances the mortality and affects the development of Spodoptera exigua larvae

A novel 2551-bp enhancin gene designated En-Dk was isolated from the Dendrolimus kikuchii nucleopolyhedrovirus genome. Sequence analysis revealed that En-Dk encodes a polypeptide chain of 792 amino acid residues containing a conserved enhancin domain and an α-helical transmembrane domain, but no signal peptide. Compared with wild-type tobacco (Nicotiana tabacum L.), transgenic tobacco showed significant phenotypic changes following En-Dk overexpression with slower growth and delayed initial flowering. An interesting finding is that the transgenic tobacco exerted a toxic effect on newly hatched Spodoptera exigua larvae, with a significant inhibitory effect on third-instar larvae in terms of body weight, pupal weight, pupation and the emergence process.