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。     

恒温下灰茶尺蛾种群两性生命表的研究

灰茶尺蛾是安徽及周边省份重点防控的茶树害虫之一。以年龄-阶段特定两性生命表为研究手段,以得出其种群特征,从而为控制其种群增长规模提供参考。结果如下:(1)灰茶尺蛾内禀增长率r=0.1883,周限增长率λ=1.207 2,净增殖率R_0=248.65粒,平均世代周期T=29.24 d。(2)特定年龄-阶段存活率在卵期至3龄幼虫期等4个阶段中较高,其峰值依次为1、0.839 1、0.824 4与0.838 8。(3)3条生殖力曲线(f_(xj)、m_x、l_xm_x)均于初产卵历约28 d时达到最大值,分别为167.76粒、85.63粒和65.67粒;生殖价值V_(xj)曲线在初产卵历约27 d时达到峰值,为307.25粒;生命期望最大值e_(0,1)=27.60d。由以上结果可得出:恒温下(26±1)℃,灰茶尺蛾种群属于r对策者,且种群处于扩增状态;自初产卵历约31 d始,灰茶尺蛾种群特定年龄存活率(l_x)急剧下降,直至成虫全部死亡;雌成虫期是灰茶尺蛾种群增长的重要贡献因子,其对后代的主要贡献集中于初产卵历经约27～28 d之时。     

Disease cycle of Austropuccinia psidii on Eucalyptus globulus and Eucalyptus obliqua leaves of different rust response phenotypes

Myrtle rust poses a significant biosecurity threat to Australia with potential for long-term damaging impacts on native flora and plant industries. This study describes the disease cycle of Austropuccinia psidii, the myrtle rust pathogen, in Eucalyptus globulus and Eucalyptus obliqua, two commercially and ecologically important species from different subgenera of Eucalyptus. Ontogeny and morphology of infection structures of A. psidii on plants of both Eucalyptus species with different rust response phenotypes, i.e. completely resistant, hypersensitive and highly susceptible, were investigated. Plants were inoculated with single-uredinium-derived urediniospores and examined by scanning electron microscopy. No differences between rust response phenotypes were observed in germination of urediniospores, formation of appressoria or length of germ tubes. The growth of germ tubes had no affinity towards stomata of either species. Histological observations indicated direct penetration by infection pegs through the leaf cuticle and no penetration beyond the epidermis on rust-resistant E. obliqua. Eucalyptus obliqua plants that were identified as susceptible to A. psidii at 3- and 6-months-old showed no disease when reinoculated with A. psidii at 12-months-old; this indicated possible early acquisition of adult plant resistance to A. psidii in this species. In the susceptible phenotype of E. globulus rust inoculation led to rapid colonization of leaf parenchyma cells with the disease cycle completed within 10 days. These findings provide valuable insights into host–pathogen interactions in the Eucalyptus–A. psidii pathosystem, which might be useful for the development of effective rust control strategies across Eucalyptus subgenera.     

增量表达Bmlipase-1的转基因家蚕的主要经济性状调查

家蚕核型多角体病毒(BmNPV)是对养蚕业危害最严重的病原之一,采用传统育种方法培育家蚕抗性品种存在经济性状和抗性呈负相关的矛盾。为了确定转基因方法能否突破该瓶颈,对先前利用家蚕品种大造建立的增量表达内源性抗病毒基因Bmlipase-1的转基因家蚕系统LI-A的主要经济性状进行调查。结果显示,LI-A的4、5龄幼虫逐日体质量及产茧量性状成绩与正常大造之间没有明显的差异,表明转基因抗病毒家蚕系统LI-A在抗性提高的同时,经济性状没有受到影响。     

甜菜夜蛾核多角体病毒可湿性粉剂生产技术的研究

报道了甜菜夜蛾核多角体病毒可湿性粉剂的生产关键技术,包括甜菜夜蛾的饲养,多角体病毒的增殖,可湿性粉剂的生产,产品质量检测等。     

Optical brightener M2R destroys the peritrophic membrane of Spodoptera exigua (Lepidoptera: Noctuidae) larvae

Observations under an environmental scanning electron microscope showed that the peritrophic membrane (PM) of Spodoptera exigua (Hübner) was smooth without pores, but there were many pores and slits in the PM of larvae fed with 10 g L(-1) optical brightener Calcofluor white M2R. After incubation of S. exigua PM in vitro with 10 g L(-1) M2R, a significant amount of proteins was released from the PM structure. M2R disrupted the structure of larval PM, resulting in greatly increased permeability and increased larval susceptibility to Syngrapha falcifera multiple nucleopolyhedrovirus infection. Continuous feeding of larvae on a diet treated with a 10 g L(-1) M2R solution significantly retarded larval development and resulted in high mortality. The destructive effect of M2R on PM was transient and reversible, depending on the presence of M2R within the midgut.     

茶尺蠖生物学特性及防治技术研究现状

综述了茶尺蠖[Ectropis oblique(Prout)]的为害特点和发生规律,阐述了近年来基于农业防治、物理防治、生物防治、化学防治等防治方法的研究进展,并展望了今后的研究重点。     

Combined effect of nucleopolyhedrovirus and Microplitis pallidipes for the control of the beet armyworm, Spodoptera exigua

BACKGROUND: Nucleopolyhedrovirus (SeNPV) and Microplitis pallidipes are important biological control agents of Spodoptera exigua populations. The interactions between these agents and their combined effect on pest control were investigated in the laboratory and in commercial greenhouses. RESULTS: Microplitis pallidipes searched for and deposited eggs in more healthy larvae than virus‐infected larvae 3 days after viral infection. Each female parasitoid that developed in a virus‐infected host oviposited in a virus‐infected host, or emerged from a cocoon carrying virus transmitted to 4.0, 7.6 or 2.4 healthy larvae respectively. Each female parasitoid exposed to a mixture of virus and 10% honey water solution transmitted the virus to 2.2 healthy larvae. In an experiment with cabbage growing in commercial greenhouses, the pest population reduction was greater by M. pallidipes carrying SeNPV (82.3–89.7% reduction) than by parasitoids without virus (59.5–62.4% reduction). CONCLUSIONS: Control of S. exigua was greater with M. pallidipes plus SeNPV than with M. pallidipes alone. Microplitis pallidipes preferred healthy hosts to infected hosts. Parasitoids were able to complete their development in virus‐infected hosts before the hosts died from the virus infection. The parasitoid ovipositors contaminated with the virus could carry and transmit SeNPV. Copyright © 2011 Society of Chemical Industry     

利用家蚕细胞表达重组蝎毒素蛋白及其杀虫效果分析

用天然毒素蛋白杀灭害虫是农林病虫害防治的一个重要发展方向。利用家蚕核型多角体病毒(BmNPV)多角体蛋白基因的部分序列与蝎毒素蛋白基因(BmK ITa1)融合表达,SDS-PAGE分析通过融合表达策略构建的含有蝎毒素蛋白基因的重组病毒具有较高的蝎毒素蛋白表达水平,重组病毒vBmBac(polh-)PH5B/35B-BmK ITa1.6His,在家蚕BmN细胞内的BmKITa1蛋白表达水平分别为0.4、0.2 mg/mL。以家蚕和棉铃虫为供试昆虫,探讨融合蝎毒素蛋白的杀虫效果,结果表明:经口添食含融合蝎毒素蛋白的BmN细胞液对不同龄期家蚕幼虫均具有毒性,尤其对低龄幼虫的毒性较强,蚁蚕添食后的死亡率达80%;给1龄期的家蚕和棉铃虫幼虫经口添食含有不同剂量融合蝎毒素蛋白的BmN细胞破碎液,当添食剂量在2.8μg/头时,家蚕的死亡率即达100%,棉铃虫的死亡率达74%。研究结果提示:BmNPV多角体蛋白编码基因的部分序列与蝎毒素蛋白基因融合表达,可提高蝎毒素蛋白的表达水平,且重组病毒表达的蝎毒素蛋白具有较好的杀虫活性,在较低剂量下即可对低龄昆虫产生良好的杀灭效果。