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。     

甜菜夜蛾危害茶树初报

甜菜夜蛾又名贪夜蛾 ( Spodoptera exigua=L aphygma exigua)是分布于热带、亚热带和温带地区的一种农作物害虫。近年来 ,在我国北方地区大发生 ,造成多种农作物受害 ,尤其是蔬菜受害更重 ,损失惊人。据许多文献记载 ,甜菜夜蛾属多食性害虫 ,寄主植物达 1 0 0多种。在我国 ,甜菜夜蛾主要危害农作物中的豆类、花生、棉花、玉米、蔬菜等 ,少见有危害茶树的报道。据作者调查和了解 ,受害严重的作物为蔬菜、花生和豆类。在害虫大发生的地块 ,幼虫还可取食禾本科杂草。从 1 999年开始 ,在青岛市崂山茶区发现 ,甜菜夜蛾还可危害茶树 ,并且在个别…     

甜菜夜蛾发生规律及其防治研究

甜菜夜蛾在福建漳州龙海每年发生9－10年,3月中下旬开始发生,4－10月份是该虫为害农作物的严重时期,其中8－9月份为全年发生危害的高峰期,通过田间药效试验,评价了不同类型的12种杀虫剂对甜菜夜蛾的防治效果,结果表明,除尽,菜喜以及米满对田间甜菜夜蛾具有较好的防效,锐颈特,杀虫单,敌杀死等药剂对田间甜菜夜蛾几乎失去防效。     

The infection of potatoes by Phoma exigua

The pathogenicities of Phoma exigua var. foveata and P. exigua var. exigua were compared by determining the relationship between incidence of infection of whole tubers or tuber pieces and various inoculum levels in soil. In natural soil var. foveata was more pathogenic than var. exigua, but in sterilized soil there were no clear differences between the two. Both varieties were isolated from some lesions derived from inoculum to which only one variety had been added indicating either natural contamination of soil or latent infection in tubers; the proportion of such lesions increased at the lower inoculum concentrations. In studies where potato plants were grown in infested soils, the incidence of stem disease and tuber disease increased at increased inoculum concentrations of var. foveata; var. exigua was not added to the inoculum but was isolated from some lesions, the proportions of such lesions again increasing at lower inoculum concentrations. The infectivity of the infested soil, assessed by a tuber-baiting method, declined soon after planting but increased prior to harvest. Laboratory studies indicated that in natural soil the infectivity was highest after 2–3 months and lowest after 10 months incubation, but in sterilized soil infectivity was highest after 5 months and lowest after 7 months incubation.     

Activity and Persistence of Steinernema carpocapsae and Spodoptera exigua Nuclear Polyhedrosis Virus against S. exigua Larvae on Soybean

Experiments were conducted to assess the effects of the entomopathogenic nematode Steinernema carpocapsae and Spodoptera exigua multinucleocapsid nuclear polyhedrosis virus (SeMNPV), alone and in combinations, on mortality of the beet armyworm, S. exigua, larvae on soybean. In 1991 tests, field-grown soybean plants were treated with S. carpocapsae at 0.3 and 0.6 nematodes/cm² of leaflet, SeMNPV at 20 and 40 polyhedral inclusion bodies (PIB)/cm², and all possible combinations. Treated leaflets were collected from plants and bioassayed with 5-day-old larvae. The combination of S. carpocapsae at 0.6 nematodes/cm² + SeMNPV at 40 PIB/cm² produced significantly higher larval mortality (61.7%) compared with either S. carpocapsae (24.8-35.1%) or SeMNPV (26.5-33.7%) alone. In 1992, similar tests were repeated using S. carpocapsae at 0.2 and 0.5 nematodes/cm², and SeMNPV at 14 and 35 PIB/cm². The combination of 0.5 nematodes/cm² + 35 PIB/cm² resulted in significantly higher larval mortality (64.0%) than either pathogen alone (41.5-49.0%). Steinernema carpocapsae and SeMNPV produced additive effects on beet arlnyworm mortality. Persistence of S. carpocapsae was 12-24 hours and SeMNPV was 96-120 hours on soybean.     

A cell strain cloned from Spodoptera exigua cell line (IOZCAS-Spex-II) highly susceptible to S. exigua nucleopolyhedrovirus infection

A cell strain (IOZCAS-Spex-II-A) cloned from IOZCAS-Spex-II, a cell line established from the fat body of Spodoptera exigua (Lepidoptera: Noctuidae) larva, was characterized, and its capability to produce S. exigua nucleopolyhedrovirus was high with infection rate exceeding 90% compared with its parental cell line IOZCAS-Spex-II that scored only 50%. Growth curve of budded virus (BV) in the strain was analyzed and the titer of BV reached the highest of 3.7?×?10⁴ pfu/mL by 96 h after inoculation. Concentration of occlusion bodies (OBs) produced by the cloned cell strain (IOZCAS-Spex-II-A) was 7.1?×?10⁷ OBs/mL, while the parental cell line produced 2.4?×?10⁷ OBs/mL. The average yield of the virus was 176 OBs/cell of IOZCAS-Spex-II-A compared with 211 OBs/cell that of the parental cell line. Significant differences were observed in virus production, growth characters, cell shape, between the parental cell line, and its clone. The cell lines (IOZCAS-Spex-II and IOZCAS-Spex-II-A) were also susceptible to Autographa californica multiple nucleopolyhedrovirus infection. In addition, they were characterized with regard to their growth rates and DNA amplification fingerprinting technique employing polymerase chain reaction.     

甜菜夜蛾幼虫饲养技术的改进

利用一次性塑料杯饲养甜菜夜蛾SpodopteraexiguaH櫣bner,一次性接入初孵幼虫,直至化蛹不再转移,也不再更换饲料。与已报道的方法相比,该方法操作简单,省工省时,可以提高工作效率。在各项饲养指标中,除平均蛹重略微偏低之外,其余指标均与已报道的数据基本一致。试验证明,采用该方法可以满足室内甜菜夜蛾的继代繁殖和批量饲养。     

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     

Identification of a hypertrehalosemic factor in Spodoptera exigua

Trehalose is a major blood sugar in insects with a range of physiological functions, including an energy source and a cryoprotectant. Hemolymph trehalose concentrations are tightly regulated according to physiological conditions. An insulin‐like peptide, SeILP1, downregulates hemolymph trehalose concentrations in Spodoptera exigua. Here, we identified a factor that upregulates hemolymph trehalose concentration in S. exigua. Hemolymph trehalose concentrations were significantly increased after immune challenge or under starvation in a time‐dependent manner. To determine endocrine factors responsible for the upregulation, stress‐associated mediators, such as octopamine, serotonin, or eicosanoids were injected, but they did not upregulate hemolymph trehalose. On the other hand, injection with Schistocerca gregaria adipokinetic hormone (AKH) significantly increased hemolymph trehalose concentration in S. exigua. During upregulation of hemolymph trehalose by AKH injection, trehalose degradation appeared to be inhibited because expression of trehalase and SeILP1 were significantly suppressed while that of trehalose phosphate synthase was not significantly changed. Interrogation of a Spodoptera genome database identified an S. exigua AKH‐like gene and its expression was confirmed. During starvation, its expression concentrations were increased, although RNA interference specific to the AKH‐like hypertrehalosemic factor (SeHTF) gene significantly prevented the upregulation of hemolymph trehalose concentrations during starvation. A synthetic peptide of SeHTF was prepared and injected into S. exigua larvae. At nanomolar concentration, the synthetic SeHTF peptide effectively upregulated hemolymph trehalose concentrations. Here we report a novel hypertrehalosemic factor in S. exigua (SeHTF).     

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。     

The spread of Phoma exigua within the potato crop

The incidence of gangrene that developed in tuber samples harvested in a systematic way from potato crops planted with surface sterilized gangrene-free seed surrounding a small plot planted with gangrene-affected seed showed that in two out of the three years marked outward spread of Phoma exigua var.foveata occurred in an uneven manner to about 4 ft (1–2 m) from the central plot. The occurrence of var. foveata was restricted to the immediate area in and around the gangrene infection locus whilst P. exigua var. exigua was more widely and evenly distributed throughout the experimental area. The incidence of infection in and around the central plot varied from year to year and it is suggested that the main method of spread of var. foveata inoculum is by rain splash. Infection by both fungi appeared to be influenced in a similar manner in all three seasons.     

甜菜夜蛾围食膜的蛋白质组鉴定

[目的]甜菜夜蛾Spodoptera exigua是农业的重要害虫,为害我国蔬菜等农作物的生长.围食膜(Peritrophic membrane,PM)是昆虫体内的第一道屏障,有助于昆虫食物消化过程和保护昆虫避免细菌或病毒的侵染.本研究选取甜菜夜蛾为实验对象,通过鉴定围食膜的总蛋白成分,为探讨围食膜与病原菌相互作用的生理机制奠定基础.[方法]选用人工饲料饲养的甜菜夜蛾5龄幼虫,剥离幼虫围食膜,利用强变性剂三氟甲磺酸(Trifluoromethane-sulfonic acid, TFMS)处理,并对围食膜蛋白进行质谱鉴定和生物信息学分析,使用BLAST鉴定蛋白的同源性,探究基因水平转移现象.[结果]本研究共鉴定出199个围食膜蛋白.这些鉴定的蛋白可富集于84条GO term(P＜0.05);此外,所鉴定的蛋白可被注释到KEGG的73条代谢通路中,并能形成多个蛋白互作网络,分别参与能量代谢、蛋白水解、过氧化氢代谢、免疫等多种过程.同时,鉴定出与抗逆性相关蛋白,具有解毒代谢等功能,提高昆虫对农药和恶劣环境的抗性.[结论]本研究对鉴定出的199个围食膜蛋白进行分析,初步揭示围食膜潜在的生物学功能,并提出一些害虫控制思路,为新型杀虫剂的研发提供了理论基础.     

SeMNPV持续性感染的甜菜夜蛾细胞株的建立

在昆虫种群中常常发生杆状病毒持续性感染,持续性感染可转变为增殖性感染而引发病毒流行病。本研究拟建立一个病毒-细胞模型,用于探讨杆状病毒持续性感染分子机制。将甜菜夜蛾核多角体病毒(Spodoptera exigua nucleopolyhedrovirus,SeMNPV)在其宿主细胞Se301中无稀释连续传代以弱化病毒毒力,用传至第8代的SeMNPV感染Se301细胞后,虽然大部分细胞因病毒感染而裂解,但仍有少量细胞存活并可传代培养,该传代细胞株命名为P8-Se301。P8-Se301细胞在对数生长期的群体生长倍增时间为58~65 h,慢于Se301细胞的生长速度。光镜和电镜观察表明,少部分P8-Se301细胞具有病毒发生基质、病毒粒子、多角体等病毒感染特征。终点稀释法和感染中心测定表明,4.14%±0.99%的P8-Se301细胞可持续释放感染性的子代病毒,但该子代病毒在Se301细胞中的复制速度较野生型SeMNPV慢。结果表明,P8-Se301细胞呈现典型的持续性感染特征。     

甜菜夜蛾核多角体病毒BAC-TO-BAC外源基因表达系统的建立

用直接克隆法将miniF-lacZ-attFn7-kan 片段插入甜菜夜蛾核多角体病毒（Spodoptera exigua multicapsid nucleopolyhedrovirus, SeMNPV）〖JP〗美国分离株（SeUS1）基因组的多角体蛋白基因框内,miniF是大肠杆菌F因子复制子,携带miniF的重组病毒能够在大肠杆菌中低拷贝稳定复制,称为bacmid。由于SeUS1由不同的SeMNPV基因型组成,每个bacmid携带了一种病毒基因型,所有bacmid构成了SeUS1分离株的BAC文库。REN对111个bacmid分析表明,SeUS1分离株中除了包含具有完整SeMNPV遗传信息的基因型外,还包括不同类型的缺失基因型。将具有完整SeMNPV基因组的基因型SeBAC10转染昆虫细胞,可产生子代病毒,故SeBAC10是一种在真核细胞和原核细胞中均能复制的穿梭质粒。因为SeBAC10中多角体蛋白基因(Seph)被插入失活,将Seph作为报告基因通过位点特异性重组方式插入位于LacZ框内转座子Tn7的附着靶位点attTn7,得到重组SeBAC10 (即SeBAC10ph)转染甜菜夜蛾培养细胞Se301后,细胞出现典型的病理变化,核中出现多角体,证明SeMNPV BAC-TO-BAC外源基因表达载体系统构建成功。     

Drimia exigua (Hyacinthaceae), a new species from Ethiopia

Drímia exigua , a small and slender species, is described from the Guder river valley in Ethiopia.     

Inheritance of chorionic malformations and insecticide resistance by Spodoptera exigua

Abstract:  Effect of exposure to the organophosphorus insecticide – fenitrothion [O,O-dimethyl-O-(4-nitro-3-methyl)phenyl] – on four generations of Spodoptera exigua Hübner (Lep., Noctuidae) larvae, with regard to the mortality and structure of the chorion of eggs laid was tested. Generations varied in the total mortality rate, although all of them showed some survival rate. The third and the fourth generations showed the lowest mortality among tested ones. Exposure to fenitrothion caused malformations in eggs. The chorion revealed cracks and diminutions of the outer layer. The quality and quantity of malformations increased proportional to the duration of exposure, e.g. the second exposed generation reveald more prominent changes than the first one. Malformations were observed in the next generations, which were not exposed to pesticide. The follicular cells, which are responsible for the structure and sculpture of the eggshell, must have inherited the malforming mechanism. Most probably, malformation takes place during the late development of eggs in the ovarioles.     

不同食物对甜菜夜蛾生长发育参数的影响

选择上海地区近年甜菜夜蛾Spodoptera exigua(Hübner)发生比较严重的甘蓝、豇豆、大葱、芦笋4种寄主植物,在温度(27±1)℃,相对湿度70%±5%,光照L:D=14:10的条件下研究了不同寄主植物对甜菜夜蛾发育特征的影响。结果表明,不同寄主植物饲喂甜菜夜蛾,甜菜夜蛾幼虫发育历期、存活率、蛹重、成虫寿命、净生殖力和内禀增长率等参数在寄主植物间有显著差异。用甘蓝饲喂的甜菜夜蛾雌虫产卵量明显高于取食大葱和芦笋的。同样,取食甘蓝的甜菜夜蛾蛹重、净生殖力和种群内禀增长率等参数明显高于取食大葱和芦笋的,说明甘蓝与其他寄主植物相比提供了较好质量的食物。