褐飞虱与白背飞虱若虫间的互作效应

用罩笼试验方法,研究了褐飞虱和白背飞虱若虫间的互作关系．结果表明,两种飞虱若虫间存在程度不同的相互作用过程．褐飞虱或白背飞虱的羽化、性别、翅型、雌虫体长和体重等生物学特性的表现都受到来自异种飞虱存在的影响．随褐飞虱比例的增加,白背飞虱的上述反应愈趋明显;反之,随白背飞虱比例的增加,褐飞虱则少有这种变化．种间密度制约效应远大于种内密度制约效应,表明两种飞虱诸种生物学特性对种间作用的反应存在着差异．     

稻虱缨小蜂对褐飞虱和白背飞虱卵的识别机制

研究了室内条件下信息化合物及稻飞虱卵的形态特征在稻虱缨小蜂识别2种卵寄主褐飞虱和白背飞虱中的作用。结果表明,褐飞虱和白背飞虱雌成虫诱导的水稻挥发物对稻虱缨小蜂的引诱作用无显著差异,各自的引诱比例(头数)分别为57.50%(23头)和42.50%(17头)。稻虱缨小蜂对2种飞虱4组材料,完整卵、磨碎卵、带卵叶鞘和若虫为害叶鞘的行为反应,除了在褐飞虱完整卵上的搜索时间极显著地长于在白背飞虱完整卵上的以外,其余的均不存在差异。挥发物捕集结果表明,褐飞虱和白背飞虱雌成虫诱导的水稻挥发物组成相非常一致。上述结果表明水稻挥发物、稻飞虱利它素及飞虱卵的形态特征在稻虱缨小蜂识别褐飞虱和白背飞虱卵中的作用不明显。文中就稻虱缨小蜂识别2种寄主的机制进行了讨论。     

褐飞虱与白背飞虱共栖时的互作效应

用笼罩试验方法,研究了褐飞虱和白背飞虱共栖时的互作效应．结果表明,在９６ ｈ内,随时间的延长,２种飞虱对不同稻株的栖息率渐趋增加,最终达２１．５～２５．０％,不表 现种间差异;脉冲试验使白背飞虱的雌性率和短翅率提高 ２２． １％和 ３９８． １％;排除试验使 白背飞虱的增殖、雌性率和雌虫短翅率各下降 ８． ８％、２０． ８％和 ４８． ０％;种间作用对增殖。 性比和翅型产生正的或负的效应．文中还讨论了种间作用存在的意义和方式．     

白背飞虱、灰飞虱mariner转座子的初步研究

根据毛里塔尼亚果蝇Drosophila mauritania的mariner转座子序列设计简并引物,以白背飞虱Sogatella furcifera和灰飞虱Laodelphax striatellus基因组DNA为模板,通过PCR反应扩增出了约500 bp的条带,经回收、克隆、测序,获得其核苷酸序列,与毛里塔尼亚果蝇mariner序列相比,核苷酸同源性均为71.3%,氨基酸同源性分别为69.5%和72%,证明白背飞虱和灰飞虱体内确实存在mariner转座子。     

凤阳县白背飞虱发生规律及综合防治技术

根据安徽省凤阳县历年水稻白背飞虱的测报资料 ,探讨了水稻白背飞虱Sogatellafurcifera在江淮流域的发生规律。通过分析影响该地区白背飞虱发生的主要影响因子并结合当地的实际情况 ,确定其综合防治策略及方法 ,为该地区白背飞虱的综合防治提供理论依据     

广东白背飞虱种群对常用杀虫剂的敏感性测定

在室内采用稻茎浸渍法测定了广东省广州市和南雄市2个白背飞虱种群对吡虫啉、呋虫胺、烯啶虫胺、噻虫嗪、噻嗪酮、吡蚜酮等6种常用农药的敏感性。结果表明:不同白背飞虱种群对吡虫啉的敏感性最高,LC50值在0.0133-0.1538 mg/L之间;对噻嗪酮敏感性最低,LC50值在0.8806-1.6948 mg/L之间。不同白背飞虱种群对同一种杀虫剂的敏感性差异较大。     

白背飞虱单克隆抗体的制备及其特性的研究

应用杂交瘤技术,制备出4株高度特异性的白背飞虱单克隆抗体,分别命名为WPH-1H9、WPH-2B6、WPH-2E12和WPH-3F12。这些抗体与其它8种昆虫未发生交叉反应,其中WPH-2B6可与白背飞虱所有虫态发生反应,其余3株只与卵和雌成虫发生反应。应用免疫双扩散法鉴定抗体类型及亚类,结果表明：WPH-2B6为IgG_2b亚类,其余均为IgG₁亚类。SDS-聚丙烯酰胺凝胶电泳和Western blot印迹分析表明,白背飞虱抗原主要由分子量分别为182、116、66.2及40 kD的4个多肽组成,其中WPH-2B6与182、116 kD的多肽结合,其余3株的单抗只与116 kD的多肽具有亲和性。最后对这些单克隆抗体在捕食作用研究中的应用潜力进行了讨论。     

白背飞虱为害对水稻产量的影响及防治指标的研究进展

白背飞虱近年来已逐步上升为我国水稻上的最重要害虫之一。该文综述了白背飞虱以不同虫口密度、在水稻不同生育期、危害不同类型水稻品种和与其他病虫害复合危害对水稻产量的影响 ,以及允许产量损失率和各地制定的防治指标 ,并建议了进一步的研究内容。     

白背飞虱灯下虫量与气象要素关系的相关分析

研究白背飞虱Sogatellafurcifera(Horvath)灯下虫量与气象要素之间的关系。相关分析表明(1)白背飞虱灯下虫量与平均气温、最高气温、最低气温和相对湿度的最优曲线估计为Logistic曲线,其中与3个温度要素之间的相关达到极显著水平,与相对湿度的相关关系达到显著水平;(2)灯下诱虫量与降水量、日照时数、温雨系数和晴雨系数的最优曲线估计为幂函数曲线,除日照时数达到显著水平外,其余3个要素均达到极显著水平;(3)对白背飞虱灯下虫量变化影响较大的因子依次为温雨系数、降水量、日照时数和晴雨系数,相应的偏相关系数分别为0.3908,-0.3727,-0.2996和-0.2268;(4)虫量与相对湿度、平均气温、最低气温和最高气温的偏相关系数分别为-0.1229,0.1152,-0.0410和-0.0106,不相关概率为20.5%~91.3%,远未达到5%的显著水平;(5)通过分析,建立白背飞虱灯下虫量预报方程,为及时进行白背飞虱大田防治提供依据。     

吡虫啉对白背飞虱抑食作用的初步研究

吡虫啉对白背飞虱取食的抑制作用可以用蜜露分泌量的减少和体重的减轻来衡量。吡虫啉处理后,白背飞虱蜜露分泌量的减少比率随浓度的加大而上升,随处理后时间的推移首先表现为上升,到达最大值后再下降,最高浓度0.0250mg/kg处理,蜜露分泌量减少最显著的第6d,减少比率为57.28%。与对照相比,吡虫啉处理后,白背飞虱体重的变化随浓度上升而加大,随时间的推移表现为持续上升,最高浓度0.0250mg/kg处理时,第8d的体重减轻比率为36.03%。     

Direct and feeding‐induced interactions between two rice planthoppers, Sogatella furcifera and Nilaparvata lugens: effects on dispersal capability and performance

Abstract. 1. A series of laboratory experiments was conducted to explore the effects of inter‐specific interactions, both direct interactive effects and those induced through previous feeding, on the dispersal capability (proportion of macropterous adults) and performance (development time and survival) of two wing‐dimorphic planthoppers, the whitebacked planthopper Sogatella furcifera and the brown planthopper Nilaparvata lugens, two pests of rice throughout Asia. 2. An asymmetric effect of inter‐specific crowding on dispersal capability was detected between the two planthoppers. With density controlled, the proportion of macropterous adults in N. lugens was higher when raised in mixed populations with S. furcifera than in pure cultures comprised of conspecifics, suggesting that interspecific effects on dispersal capability are stronger than intraspecific effects. In contrast, interspecific effects on macroptery (%) were weaker than intraspecific impacts for S. furcifera. 3. This trend was parallelled by adverse competitive effects on survival, with interspecific effects stronger than intraspecific impacts for N. lugens and intraspecific effects stronger for S. furcifera. 4. Crowding also affected the incidence of macroptery indirectly through feeding‐induced changes in plant physiology. Rearing N. lugens on plants fed on previously by heterospecifics resulted in a higher incidence of macroptery in females and protracted development than for N. lugens raised on plants fed on previously by conspecifics. By contrast, the intraspecific effect of previous feeding was stronger than the interspecific effect in S. furcifera, with higher macropter production and prolonged development occurring on plants exposed previously to conspecifics. 5. The results suggest that interspecific interactions between herbivorous insects, both direct and via feeding‐induced changes in plant physiology, can have negative consequences for performance and survival and promote the production of flight‐capable adults that can disperse.     

Induction of P450 genes in Nilaparvata lugens and Sogatella furcifera by two neonicotinoid insecticides

Nilaparvata lugens and Sogatella furcifera are two primary planthoppers on rice throughout Asian countries and areas. Neonicotinoid insecticides, such as imidacloprid (IMI), have been extensively used to control rice planthoppers and IMI resistance consequently occurred with an important mechanism from the over‐expression of P450 genes. The induction of P450 genes by IMI may increase the ability to metabolize this insecticide in planthoppers and increase the resistance risk. In this study, the induction of P450 genes was compared in S. furcifera treated with IMI and nitromethyleneimidazole (NMI), in two planthopper species by IMI lethal dose that kills 85% of the population (LD₈₅), and in N. lugens among three IMI doses (LD₁₅, LD₅₀ and LD₈₅). When IMI and NMI at the LD₈₅ dose were applied to S. furcifera, the expression changes in most P450 genes were similar, including the up‐regulation of nine genes and down‐regulation of three genes. In terms of the expression changes in 12 homologous P450 genes between N. lugens and S. furcifera treated with IMI at the LD₈₅ dose, 10 genes had very similar patterns, such as up‐regulation in seven genes, down‐regulation in one gene and no significant changes in two genes. When three different IMI doses were applied to N. lugens, the changes in P450 gene expression were much different, such as up‐regulation in four genes at all doses and dose‐dependent regulation of the other nine genes. For example, CYP6AY1 could be induced by all IMI doses, while CYP6ER1 was only up‐regulated by the LD₅₀ dose, although both genes were reported important in IMI resistance. In conclusion, P450 genes in two planthopper species showed similar regulation patterns in responding to IMI, and the two neonicotinoid insecticides had similar effects on P450 gene expression, although the regulation was often dose‐dependent.     

cycle基因对噻嗪酮、噻虫嗪防治白背飞虱效果影响探索研究

白背飞虱Sogatella furcifera是我国重要的迁飞性水稻害虫,长期以来,其防治手段主要是化学防治。大量使用化学农药易导致环境污染及害虫抗药性增加等,因此需要探索高效的农药使用方法。本研究在1 d内不同时间点用0.27 g/L噻虫嗪、5 mL/L噻嗪酮对白背飞虱的致死率进行检测,结果发现,7∶00时噻虫嗪、噻嗪酮浸染72 h后的校正死亡率均最低,分别为54%、13.9%;16∶00时噻虫嗪、噻嗪酮浸染72 h后的校正死亡率均最高,分别为89.8%、44.9%。定量结果表明节律基因Sfcycle在白背飞虱雌虫或雄虫的中肠表达量最高,4龄和5龄若虫期在蜕皮前表达量比蜕皮后高,成虫期表达量相对稳定。RNAi研究结果发现Sfcycle能够影响白背飞虱P450基因SfCYP4DE1和SfCYP353D1v2的表达,用农药处理干涉后的白背飞虱死亡率都在7∶00、16∶00两个时间点都增高,且没有显著性差异,表明Sfcycle基因能够影响噻虫嗪、噻嗪酮对白背飞虱的防治效率。     

白背飞虱的再迁飞能力

通过室内模拟试验研究了白背飞虱经过一次远迁降落、取食不同水稻品种后的再迁飞能力。根据吊飞试验的持续飞行时间可将白背飞虱种群划分为居留型(<30 min)、迁飞型(≥30 min)、远迁型(>420 min)和再迁飞型(第二次吊飞持续飞行时间 ≥30 min)。在所测的558头白背飞虱中,再迁飞型的比率为5.7%;而在112头迁飞型个体中,再迁飞的比率为28.6%。取食不同品种的水稻对白背飞虱的飞行能力和再迁飞能力有显著影响。取食感虫水稻的白背飞虱飞行能力和再迁飞能力较强,再迁飞的比率也较高 (>5%)。吊飞前后取食常规稻与耐虫品种组合的飞虱的再迁飞时间则较短,再迁飞比率也较低;但吊飞前后均以耐虫品种饲喂的个体,反而也表现出较高的再迁飞比率和中等水平的再迁飞时间。而且,第一次飞行360 min以上的个体具有较强的再迁飞潜力。交配只对6日龄雌虫和2日龄雄虫的飞行能力有显著影响。     

青翅蚁形隐翅虫对稻纵卷叶螟和白背飞虱的捕食作用

应用二次回归正交设计建立青翅蚁形隐翅虫对稻纵卷叶螟和白背飞虱捕食作用的数学模型分别为：Y＇cm=3.5072＋1.6671x1＋1.7200x2-1.004x3＋0.6375x1x2-0.7625x1x3-0.2625x2x3＋0.6020x^21-0.3538x^22-0.0807x^23;Y＇sf=3.7612＋0.4015x1＋0.2573x2＋1.6645x3＋0.1250x1x3＋x2x3＋0.3372x^21-0.4820x^22＋0.0641x^23.结果表明,青翅蚁形隐翅虫对白背飞虱表现出更强的取食选择性.当猎物密度较低时,青翅蚁形隐翅虫对稻纵卷叶螟的捕食作用为密度制约性,当猎物密度较高时,青翅隐翅虫对白背飞虱的捕食作用为密度制约性.     

四种生物农药及其与二种化学农药混配对稻飞虱混合种群的防治效果

试验以喷雾法研究4种生物农药及其与2种化学农药组合混用对水稻褐飞虱Nilaparvata lugens(Stal)和白背飞虱Sogatella furcifera(Horvath)混合种群的防治效果。结果表明:0.36%苦参碱AS、0.5%藜芦碱WP、1.8%阿维菌素EC、400亿孢子/克白僵菌WP,分别以1500mL/hm2、3000g/hm2、900mL/hm2、1800g/hm2的制剂用量单独使用,只有阿维菌素效果较好,药后7、14d的防效分别达到了73.3%和82.3%,但与对照药剂48%毒死蜱EC1500mL/hm2和25%噻嗪酮WP750g/hm2的防效差异极显著。而4种生物农药与2种化学农药分别以单用剂量减半混合使用的8个处理中,①苦参碱+毒死蜱、②藜芦碱+毒死蜱、③阿维菌素+毒死蜱、④球孢白僵菌+毒死蜱、⑤苦参碱+噻嗪酮、⑥藜芦碱+噻嗪酮6种组配,药后1d的校正防效为81.8%～89.2%,3d为88.2%～96.5%,7d为95.6%～98.1%,14d为86.0%～97.8%。因此,以上生物农药与化学农药的6种组合混用可以有效防治稻飞虱低龄若虫。     

Changes in DNA methylation fingerprint of Quercus ilex trees in response to experimental field drought simulating projected climate change

Rapid genetic changes in plants have been reported in response to current climate change. We assessed the capacity of trees in a natural forest to produce rapid acclimation responses based on epigenetic modifications. We analysed natural populations of Quercus ilex, the dominant tree species of Mediterranean forests, using the methylation‐sensitive amplified polymorphism (MSAP) technique to assess patterns and levels of methylation in individuals from unstressed forest plots and from plots experimentally exposed to drought for 12 years at levels projected for the coming decades. The percentage of hypermethylated loci increased, and the percentage of fully methylated loci clearly decreased in plants exposed to drought. Multivariate analyses exploring the status of methylation at MSAP loci also showed clear differentiation depending on stress. The PCA scores for the MSAP profiles clearly separated the genetic from the epigenetic structure, and also significantly separated the samples within each group in response to drought. Changes in DNA methylation highlight the large capacity of plants to rapidly acclimate to changing environmental conditions, including trees with long life spans, and our results demonstrate those changes. These changes, although unable to prevent the decreased growth and higher mortality associated with this experimental drought, occurred together with a dampening in such decreases as the long‐term treatment progressed.     

白背飞虱对水稻抗虫品种N_(22)的适应性研究

在室内连续用感虫品种TN1和抗虫品种N2 2 单管饲养白背飞虱 (Sogatellafurcifera)种群 ,研究它对抗虫水稻品种的适应性及其体内保护酶的变化 .结果表明 ,白背飞虱在感虫品种TN1和抗虫品种N2 2品种上饲养 1至 2代 ,其卵历期、若虫期和全世代历期均无明显差异 .从感虫品种TN1转移到抗虫品种N2 2 上饲养 1代 ,白背飞虱的若虫存活率、雌成虫寿命、体重、蜜露量、产卵量和内禀增长率等均低于在抗虫品种上连续饲养 2代 ,而后者又低于在感虫品种上饲养的指标 .白背飞虱在抗虫品种上连续饲养 2代后 ,体内保护酶中超氧化物岐化酶 (SOD)和过氧化氢酶 (CAT)活性逐渐接近于感虫品种上连续饲养的结果 ,说明白背飞虱从感虫品种转到抗虫品种在开始时并不适应 ,经过连续繁殖多代后白背飞虱逐渐适应 ,最后导致抗虫品种的抗性丧失     

水稻白背飞虱发生程度的长期预测模型

气象条件影响白背飞虱Sogatellafurcifera发生发展 ,根据海气相互作用原理 ,海温的变化会引起大气环流系统的变化 ,同样制约各地气象条件。作者将西太平洋海温作为长期预报因子 ,根据场相关分析方法 ,找出与水稻白背飞虱发生程度各指标相关的强信号海区 ,应用最优化相关处理技术 ,大大增加了虫情发生指标和海温之间的相关度 ,建立了水稻白背飞虱始见期、迁入虫量及第五 ( 2 )代虫量可靠的长期预测模型 ,模型均通过了α=0 0 1显著性水平 ,拟合及试报结果理想 ,预报模型切实可行 ,可以投入业务使用 ,此研究对虫害防治和水稻生产具有重要指导意义     

水稻品种抗性对褐飞虱和白背飞虱种群动态的影响

用ＴＮ１、Ｎ２２、ＡｓＤ７和Ｐｔｂ３３等４个抗虫性差异明显的水稻品种测定了褐飞虱和白背飞虱在它们上面的栖息率、落卵量、卵存活率、若虫存活和发育状况,以及后代种群数量表现。结果表明,Ｐｔｂ３３通过减少２种飞虱的栖息率、落卵量,降低卵和若虫存活率,延长若虫的发育时间,抑制后代的种群数量增长,表现出明显的抗性。Ｎ２２对白背飞虱、ＡｓＤ７对褐飞虱的后代种群建立与发展均表现明显的抑制作用。２种飞虱在ＴＮ１上