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1.
针对长江中游棉区棉花多虫复合危害问题,设计了6种害虫4种组合的复合危害系统.运用通径分析方法,定量描述了多种害虫对棉花的侵害及其间的互作效应.通过多种害虫对棉花产量和品级的直接影响效应和间接影响效应分析,认为当多虫复合危害时,害虫间的相互作用就其对作物的侵害而言,表现为增强效应和减弱效应.在此基础上,研究并制定了“两红”(棉红铃虫和朱砂叶螨)复合危害动态防治指标,经验证、示范及推广应用,取得了显著的经济、生态和社会效益.  相似文献   

2.
水稻三种主要害虫复合为害损失的研究   总被引:7,自引:2,他引:5  
张文庆  古德祥 《昆虫知识》1994,31(6):321-323
三化螟、稻纵卷叶螟和稻飞虱类是南方水稻的主要害虫,常在水稻生长中后期同时造成为害。网室接虫试验表明:水稻产量损失率与三种害虫的密度呈线性关系,回归方程式为:y=0.0870+032431x1+0.5075x2+0.1583x3。文中对多种病虫复合为害损失预测模型的一般形式及复合防治指标的应用进行了讨论。  相似文献   

3.
对营建荔枝 旋扭山绿豆复合种植系统和荔枝单一种植系统的昆虫群落结构及动态进行系统调查.结果表明,复合种植园中荔枝害虫总数显著减少,仅为单一种植园的61.27%,在果实生长关键期的5月份的数量仅是单一种植园的50.45%.旋扭山绿豆与荔枝树存在相互协调关系:两者具较少共同害虫,其害虫却存在多种共同天敌;旋扭山绿豆冬季开花为天敌昆虫越冬提供庇护场所和替代食物,两者花期基本衔接,利于害虫天敌的生存及繁殖.在荔枝开花和荔果生长期的3~6月份,复合园荔枝树上的天敌数量与害虫数量之比分别为单一园的4.22、2.34、2.28和20.63倍,有效地发挥了对荔枝害虫的控制作用.  相似文献   

4.
复合污染研究的新进展   总被引:63,自引:4,他引:59  
对多种污染物相互作用形成的复合污染效应的研究已成为环境科学发展的重要方向之一。本文从元机复合污染、无机-有机复合污染以及有机复合污染3个方面对复合污染效应的最新进展进行了综述,并从化学、生理学、酶学、细胞学等角度出发探计了复合污染机理,指出了复合污染研究中存在的若干问题和发展方向。  相似文献   

5.
扶桑绵粉蚧Phenacoccus solenopsis Tinsley是一种新人侵的危险性害虫,寄主范围广,对我国棉花和番茄等多种作物的安全生产构成威胁.本文从危害特点、形态特征及生物学特性对该害虫进行了概述.并简要概括了对其危害的关键防治技术.  相似文献   

6.
沈文静  刘来盘  方志翔  张莉  刘标 《昆虫学报》2021,64(10):1187-1195
【目的】转Bt基因棉花和转Bt基因杨树在我国已推广使用。本研究的目的是调查和分析不同转基因杨棉复合系统内地上节肢动物群落多样性变化,为转基因杨树大规模应用提供生态安全方面的数据。【方法】2019年4-10月,在河北任丘采取欧洲黑杨Populus nigra林下种植转基因棉花Gossypium hirsutum的模式,设置转基因杨树 转基因棉花(复合生态系统1)和非转基因杨树-转基因棉花(复合生态系统2)两种杨棉复合系统,调查杨树和棉花地上部植株节肢动物种类和个体数量,比较节肢动物各功能群的物种数量和个体数量以及香农指数、优势集中性指数、均匀度指数等群落多样性指数,并测定了转基因杨树和棉花叶片Bt蛋白含量。【结果】复合生态系统1中转基因杨树和棉花各自植株上鳞翅目种群累计个体数均显著低于复合生态系统2相应植株上的个体数量。转基因杨树上叶甲类累计个体数量显著高于非转基因杨树上的,寄生蜂类累计个体数量则显著低于非转基因杨树上的。在6月5日、6月21日和9月7日的调查中,转基因杨树上的节肢动物群落香农指数显著高于非转基因杨树上的。除鳞翅目害虫外,2个复合系统中棉株上节肢动物各功能群累计个体数量无显著性差异,香农指数、优势集中性指数和均匀度指数随时间变化的趋势基本一致且同一调查时间无显著性差异,仅在8月17调查中复合生态系统1中棉株上节肢动物香农指数显著高于复合生态系统2棉株上的。将杨树和棉花上节肢动物各类群累计数量相加作为系统整体,复合生态系统1和复合生态系统2在香农指数、优势集中性指数和均匀度指数数值上无显著差异。在调查后期,2个复合系统中节肢动物种群均向杨树叶片聚集。转基因棉花叶片Bt蛋白含量在各调查期均显著高于转基因杨树叶片的。【结论】转基因杨树对靶标害虫种群数量有较好的控制作用,对同系统内棉花上鳞翅目害虫数量亦有协同控制作用。转基因杨棉复合系统中地上节肢动物群落结构稳定,对系统内棉花地上部节肢动物群落多样性无显著影响。靶标害虫对转Bt基因杨树的抗性发展需持续监测。  相似文献   

7.
当今社会随着经济和科技的发展,多种有害职业因素往往共同存在于同一岗位。复合因素对机体健康影响的相互作用包括四种情况:协同作用、相加作用、拮抗作用和无关作用。噪声和高温作为有害的职业因素常存在于同一岗位,那么噪声复合高温对机体健康会产生怎样的影响,这两种环境因素是否存在复合效应?文献报道不一。噪声和高温联合对听觉系统、心血管系统、神经系统的影响可能表现为协同、相加、拮抗和无关作用,对呼吸系统的影响表现为拮抗作用,目前,研究结果不一致主要原因是实验条件和暴露方法的不一致。我们认为将来的研究热点集中在噪声和高温联合产生复合效应的条件及剂量反应关系研究、机制及防治措施研究,噪声和高温联合对其他系统如消化、免疫系统是否存在复合效应也值得深入研究。  相似文献   

8.
害虫密度与作物产量损失预测的一种新方法   总被引:6,自引:1,他引:5  
本文首次引入幂指模型(y=yLMexp(-bd^α)来模拟害虫密度与作物产量间的关系。通过对15组不同来源的害虫与作物竞争资料的模拟,证明幂指模型具有实际性的生物学意义,能准确地描述多种害虫和多种作物间的危害关系,预测害虫危害作物可能造成的产量损失,为害虫的经济防治提供了一种新的研究方法。  相似文献   

9.
中棉所41、鲁棉研15对斜纹夜蛾抗性的初步研究   总被引:1,自引:1,他引:0  
斜纹夜蛾[Spodoptera litura (Fabricius)]是一种多食性、暴食性害虫。已知寄主植物有99科290多种,主要为害十字花科蔬菜、水生蔬菜及甘薯、棉花、大豆等作物。斜纹夜蛾以幼虫取食棉花的叶片,严重时吃光叶片,钻蛀蕾、花、铃。有关研究甚多,但该虫与转基因棉关系方面的研究则未见报道,为此作就此做了一些探索。  相似文献   

10.
灭虫新法     
世界上的害虫约有一万多种,其中六千多种是农业害虫,我国的农业害虫约有两千多种。这些害虫一般会使收成减少百分之二十五左右,严重的几乎颗粒无收。人类在与害虫的长期斗争中,总结出许多战术,如以药治虫、以虫治虫、以菌  相似文献   

11.
Myeloperoxidase (MPO) is an important component of the neutrophil's antimicrobial armory and has been implicated in promoting tissue damage in numerous inflammatory diseases. For the first time the standard reduction potential of the redox couple compound II/native enzyme has been determined to be (0.97+/-0.01)V at pH 7.0 and 25 degrees C. This was achieved by rapid mixing of preformed compound II with either tyrosine or nitrite by using the sequential-mixing stopped-flow technique and measuring spectrophotometrically the concentrations of the reacting species and products at equilibrium. Using the recently determined standard reduction potential for the couple compound I/native enzyme (1.16 V), the reduction potential of the couple compound I/compound II was calculated to be 1.35 V at pH 7 and 25 degrees C. These data reveal substantial differences between the two known heme peroxidase superfamilies and reflect the dramatic differences observed in the oxidisability of substrates by the MPO redox intermediates compound I and compound II.  相似文献   

12.
The cotton plant, Gossypium hirsutum, hosts various pests that damage different structures. Among these pests, Spodoptera cosmioides (Walker) and Spodoptera eridania (Cramer) (Lepidoptera: Noctuidae) are considered important. The objectives of this study were to characterize and to quantify the potential damage of S. eridania and S. cosmioides feeding on different structures of cotton plants. For this purpose, newly-hatched larvae were reared on the following plant parts: leaf and flower bud; leaf and boll; flower bud or boll; and leaf, flower bud and boll. The survival of S. cosmioides and S. eridania was greater than 80% and 70% for larvae fed on cotton plant parts offered separately or together, respectively. One larva of S. eridania damaged 1.7 flower buds, but did not damage bolls, while one larva of S. cosmioides damaged 5.2 flower buds and 3.0 cotton bolls. Spodoptera eridania and S. cosmioides can be considered species with potential to cause economic damage to cotton plants because they can occur throughout cotton developmental stages causing defoliation and losses of reproductive structures. Therefore, the results validate field observations that these two species of Spodoptera are potential pests for cotton.  相似文献   

13.
The sequence and relative injuriousness of insect pests was studied for three successive years in unsprayed cotton of the Namoi Valley. Heliothis punctigera Wallengren, the native budworm, and to a lesser extent H. armigera (Hübner), the cotton bollworm, prevented the setting of full crops by destroying buds and bolls. After setting, high proportions of bolls were injured by Earias huegeli Rogenhofer, the rough bollworm. Incidental damage was caused to seedlings by Thrips imaginis Bagnall, the plague thrips, and lo leaves by Anomis flava Fabricius, the cotton looper, and by Austracris guttulosa (Walker), the spur-throated locust. In commercial crops, pest control must rely on the use of broad-spectrum insecticides: H. armigera is currently resistant to several of these, and has become the principal species in the local population of cotton pests. A number of enviromental features impede the natural control of pests in the southerly areas where cotton is now produced. In comparison to the older dryland cropping practised in central Queensland, a higher yield is necessary to cover the production costs of irrigated cotton; a shorter growing season prevents the plants from compensating effectively for insect damage and the natural enemies of cotton pests are less abundant and less active.  相似文献   

14.
Boric acid and compound containing nitrogen, 2,4,6-tri[(2-hydroxy-3-trimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-HTAC) were used to finish cotton fabric. The flame retardant properties of the finished cotton fabrics and the synergetic effects of boron and nitrogen elements were investigated and evaluated by limited oxygen index (LOI) method. The mechanism of cross-linking reaction among cotton fiber, Tri-HTAC, and boric acid was discussed by FTIR and element analysis. The thermal stability and surface morphology of the finished cotton fabrics were investigated by thermogravimetric analysis (TGA) and scanning electron microscope (SEM), respectively. The finishing system of the mixture containing boron and nitrogen showed excellent synergistic flame retardancy for cotton fabric. The cotton fabric finished with mixture system had excellent flame retardancy. The LOI value of the treated cotton fabric increased over 27.5. Tri-HTAC could form covalent bonds with cellulose fiber and boric acid. The flame retardant cotton fabric showed a slight decrease in tensile strength and whiteness. The surface morphology of flame retardant cotton fiber was smooth.  相似文献   

15.
湖北棉区转Bt基因棉对棉铃虫的控制作用   总被引:8,自引:2,他引:6  
2000-2001年通过田间系统调查,表明转Bt基因棉(品种为GK19)在湖北江汉平原棉区对棉铃虫抗性稳定。试验设3个处理:转Bt基因棉化防田(使用化学农药控制害虫)、转Bt基因棉自控田(依靠天敌控制害虫)及常规棉对照田(利用综合防治措施控制害虫)。从棉铃虫的第2代到第5代整个发生期内,即使在不进行化学防治的情况下,棉铃虫在Bt棉田的发生量也保持在极低的水平(最高百株虫量为12头)。室内饲养结果表明,转Bt基因棉对棉铃虫的生长发育(幼虫体重、蛹重)有较为明显的影响,使6龄幼虫体重减少25.6%,蛹重减少18.2%。棉铃虫幼虫取食转Bt基因棉组织后,发育迟缓,相对于常规棉喂养的整个发育历期延长17 d,使棉铃虫在田间的危害减少至少一个世代。另外,接虫试验表明,棉铃虫幼虫在常规棉上的取食时间是转Bt基因棉株上的6.1倍,极大地减轻了棉铃虫的危害程度。  相似文献   

16.
转基因棉花Bt毒蛋白的表达及其生态学效应   总被引:9,自引:0,他引:9  
张少燕  谢宝瑜 《昆虫知识》2002,39(5):328-335
苏云金杆菌毒蛋白 (Bacillusthuringiensisgtoxicprotein)基因导入棉花植株后获得的转Bt棉可以特异性地毒杀棉铃虫及鳞翅目的一些其它害虫 ,有效地保护棉花植株不受此类棉花害虫的危害。Bt毒蛋白在棉花植株中的表达受一些内外界因素的影响而呈明显的时空变化。转Bt棉除了严重影响靶标害虫自身外 ,还能对其它一些非靶标昆虫和环境产生影响。另外 ,该文还对害虫对Bt棉的抗性以及防止害虫产生抗性的治理对策进行了综述  相似文献   

17.
BT基因棉与常规棉主要害虫及天敌生态位的比较研究   总被引:7,自引:0,他引:7  
本研究了BT基因棉与常规棉主要害虫及天敌的生态位。结果表明:主要害虫及天敌的种类一致,但棉铃虫幼虫的数量差异显;33B棉田各昆虫种群的生态位宽度指数偏高;棉铃虫、棉蚜对主要天敌的生态位重叠指数偏高。应用生态位概念分析了造成区别的原因。  相似文献   

18.
目的制备复方多糖口服液,并进行定量分析,对各项指标进行检测。方法采用水提醇沉法制备复方多糖口服液,薄层色谱法进行定性鉴别,苯酚-硫酸法测定含量。结果检测波长为490 nm,在4.86~24.7mg范围内多糖呈线性关系,加样回收率为99.84%。结论本法简便易行,结果稳定,可做复方多糖口服液中多糖的含量测定方法。  相似文献   

19.
Bt-transgenic cotton has proven to be highly efficient in controlling key lepidopteran pests. One concern with the deployment of Bt cotton varieties is the potential proliferation of non-target pests. We previously showed that Bt cotton contained lower concentrations of insecticidal terpenoids as a result of reduced caterpillar damage, which benefited the aphid Aphis gossypii. It is thus important that non-target herbivores are under biological control in Bt cotton fields. The induction or lack of induction of terpenoids could also influence the quality of aphid honeydew, an important food source for beneficial insects. We therefore screened A. gossypii honeydew for cotton terpenoids, that are induced by caterpillars but not the aphids. We then tested the influence of induced insect-resistance of cotton on honeydew nutritional quality for the aphid parasitoid Lysiphlebus testaceipes and the whitefly parasitoid Eretmocerus eremicus. We detected the cotton terpenoids gossypol and hemigossypolone in A. gossypii honeydew. Although a feeding assay demonstrated that gossypol reduced the longevity of both parasitoid species in a non-linear, dose-dependent manner, the honeydew was capable of sustaining parasitoid longevity and reproduction. The level of caterpillar damage to Bt and non-Bt cotton had no impact on the quality of honeydew for the parasitoids.These results indicate that the nutritional quality of honeydew is maintained in Bt cotton and is not influenced by induced insect resistance.  相似文献   

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