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     

甜菜夜蛾抗寒与越冬能力研究

研究了甜菜夜蛾不同虫态的过冷却点、耐低温能力、可能的越冬虫态及其越冬能力,并结合气象资料的分析,初步确定了我国甜菜夜蛾的越冬北界.甜菜夜蛾3～5龄幼虫的过冷却点较高,分别为-11.17℃、-11.96℃和-10.50℃(平均-11.21℃),预蛹期次之,为-12.47℃,蛹期最低,平均为-17.16℃.在5℃、0℃、-10℃和-5℃条件下,甜菜夜蛾各种虫态的LT50、LT90和LT99.9均随温度的降低而缩短,尽管不同虫态的耐低温能力有很大的差别.其耐低温能力由弱至强的排列顺序依次为卵<成虫<幼虫<蛹.这些结果表明,蛹是甜菜夜蛾的四个虫态中耐低温能力最强的,因而是最可能的越冬虫态.但由于蛹在0℃条件下的LT99.9为38.06d,表明甜菜夜蛾在冬季0℃以下的温度超过38d的地区不能越冬.另外,连续两年冬春的田间试验结果表明,蛹在北京西郊越冬死亡率均为100%,说明甜菜夜蛾在北京地区不能越冬.根据这些结果并结合我国气温的变化规律,初步将我国甜菜夜蛾的越冬北界定于北纬38°左右,即1月份-4℃等温线左右.     

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。     

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。     

A chromosome-level genome assembly of the beet armyworm Spodoptera exigua

BackgroundThe beet armyworm Spodoptera exigua is a polyphagous caterpillar that causes serious damage to many species of crops and vegetables. To gain insight into how this polyphagous insect differs from less harmful oligophagous species, we generated a chromosome-level assembly and compared it to closely related species with the same or different feeding habits.ResultsBased on Illumina and Pacific Biosciences data and Hi-C technology, 425.6 Mb of genome sequences were anchored and oriented into 31 linkage groups, with an N50 length of 14.8 Mb. A total of 24,649 gene models were predicted, of which 97.4% were identified in the genome assembly. Chemosensory genes are vital for locating food: of the four main families, odorant-binding proteins, chemosensory proteins and olfactory receptors showed little difference, whereas gustatory receptors are greatly expanded in S. exigua. Examination of other polyphagous insects confirmed this difference from oligophagous congeners and further identified the bitter receptor subfamily as being particularly affected.ConclusionOur high-quality genome sequence for beet armyworm identified a key expansion of the bitter gustatory receptor subfamily in this and other pests that differs crucially from more benign relatives and offers insight into the biology and possible future means of control for these economically important insects.     

甜菜夜蛾核型多角体病毒在宿主种群中的垂直传播研究

以两种浓度的病毒液感染甜菜夜蛾4龄、5龄幼虫,以研究甜菜夜蛾核型多角体病毒从亲代到子代垂直传递的方式和效率。实验结果表明,该病毒可通过母体介导(卵内、卵表)和父体介导等3种方式传递给子代,造成子代感染。幼虫经口感染后母体介导传递实验表明,病毒垂直传播可引起20%～48%的子代幼虫病死,并能使子代成虫产卵量下降;母体介导传播实验中,以5%福尔马林进行卵表面消毒证实仍有18.8%的幼虫感染病毒死亡,表明了该病毒可经卵内传播,并同时存在着附卵传播;母体介导传递实验还表明病毒对宿主有弱化作用,亲代免于病死的蛹重量减轻,羽化所得雌成虫的产卵量下降,产卵期延长。以交互配对将感染与未感染的雌雄成虫彼此交配,表明雄成虫精子也能垂直传递病毒(父体介导),引起20％～40%子代幼虫感病死亡。成虫经口感染,对所产卵块表面消毒后,仍导致28.6%的子代幼虫死于病毒感染,也表明存在卵内传播。     

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。     

Nutrient utilization by caterpillars of the generalist beet armyworm, Spodoptera exigua

Abstract.  Beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), caterpillars are destructive crop pests responsible for considerable annual economic losses. These generalist herbivores are challenged with a diversity of dietary choices that can impact their survival, development and fecundity. In the present study, dietary choices of S. exigua caterpillars, based on the protein to digestible carbohydrate (P : C) ratio of the food, and the impact of nutritionally unbalanced foods on caterpillar performance are assessed. In choice experiments, individual third-instar caterpillars are offered simultaneously a P-biased and a C-biased food until pupation. Caterpillars feed nonrandomly and select a slightly P-biased diet (22P : 20C). In no-choice experiments, second instar caterpillars are reared until pupation on diets ranging in P : C ratio from extremely P- to extremely C-biased. High mortality and delayed development are observed on the C-rich, P-poor diets, highlighting the potential deleterious effects of excess carbohydrates and the importance of protein for growth and development. Diet-dependent differences in pupal weight or pupal lipid reserves are not observed. This contrasts with closely-related Spodoptera species where pupal mass and lipid stores increase on C-rich, P-poor diets. On the extremely P-biased diet, performance is similar to that of individuals reared on the self-selected diet, suggesting that these caterpillars may efficiently be deaminating excess amino acids to generate carbon skeletons, which are shunted into lipid biosynthesis. Spodoptera exigua caterpillars exhibit flexible and efficient pre-ingestive nutrient intake regulation and post-ingestive utilization, allowing these generalist feeders to cope with the heterogeneous diets they may encounter.     

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.     

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。     

温度对甜菜夜蛾飞行能力的影响

温度对甜菜夜蛾飞行能力有显著的影响（P<0.05）。在16～32℃内,成虫均能进行正常的飞行活动。24℃下的成虫飞行能力最强,在15 h的吊飞飞行中,成虫飞行距离最远（37.14 km）、飞行速度最快（0.87 m/s）、飞行时间最长（11.73 h）。温度低于２０℃或高于２８℃时,其飞行能力均显著降低。甜菜夜蛾在不同温度下飞行时对主要能源物质（甘油三酯）的利用效率不同。在较适宜的温度下,尽管成虫飞行消耗的甘油三酯较多,但单位飞行距离所消耗的甘油三酯却较少,即利用效率较高,表明成虫飞行能源物质利用效率的不同是导致其在不同温度下飞行能力产生差异的主要原因之一。     

Reproduction-flight relationship in the beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae)

To evaluate the relationship between reproduction and migratory flight, we examined ovaries, tethered flight, and egg laying in the beet armyworm, Spodoptera exigua (Hübner). Ovarian development in female S. exigua was classified into five stages in relation to the postemergence age of the moths. Oviposition peaked at ovarian stages III and IV. Mating accelerated ovarian development in this species, and thus the mated females developed faster than the virgin moths in ovaries. In virgin adults, flight capacity increased from the first day to the third day after emergence and remained at a high level until the moths were 7 d old. In contrast, the mated moths reached the maximum flight capacity in 2 d after emergence and maintained a high level until the age of 7 d. However, mating status could not influence the flight capacity of the beet armyworm, although there were general differences in flight capacity between virgin and mated adults at the same age. Moreover, significant correlations between the number of eggs laid and the flight capacity were not performed by the mated moths. These results showed that mating status and ovarian development did not seem to influence flight capacity in the beet armyworm, which was not in agreement with the definitions of the oogenesis-flight syndrome observed in many other migratory insects.     

Molecular cloning and characterization of a diapause-specific peptide in the beet armyworm,Spodoptera exigua

The leaf beetle, Gastrophysa atrocyanea, diapause-specific peptide (DSP), which plays a role in diapause, inhibits Ca^2 + channels and has antifungal activity. Here, we show the molecular cloning and characterization of a diapause-specific peptide in the beet armyworm Spodoptera exigua. The S. exigua diapause-specific peptide (SeDSP) gene consists of only one exon encoding 63 amino acid residues. A comparative analysis showed that mature SeDSP consists of 40 amino acid residues including six cysteines, which are similar to those of S. littoralis Spodomicin and G. atrocyanea DSP. The SeDSP was expressed as a 4.5 kDa peptide in baculovirus-infected insect cells. SeDSP was constitutively expressed in the epidermis of S. exigua larvae and pupae after molting and metamorphosis. In addition, recombinant SeDSP showed antibacterial activity against Bacillus megaterium.     

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。