共查询到20条相似文献,搜索用时 93 毫秒
1.
2.
3.
4.
对中国有机农业和有机产业发展基本情况及在全球有机农业和有机产业发展中所处地位进行分析,认为中国有机农业和有机产业由于经济发展取得成就、有机发展政策氛围、有机消费群体和有机市场发展潜力等具有较广阔的发展前景,但由于发展基础薄弱、政府推动作用不明显、有机农业基础研究相对滞后、有机生产推广体系缺失、有机标准制定国际话语权不高和有机市场机制不健全等,中国有机农业和有机产业发展面临严峻挑战。为确保中国有机农业和有机产业持续健康发展,要正视中国有机发展所处阶段、统筹中国有机发展、重视有机市场建设、加强有机基础研究工作和建立完善的监督约束机制。 相似文献
5.
天敌昆虫控害机制与可持续利用 总被引:3,自引:0,他引:3
天敌昆虫是自然生态系统内抑制害虫种群的重要因子,利用天敌昆虫控制农业害虫是安全有效的害虫控制策略,也是未来害虫管理发展的方向.本文在系统总结国内外研究进展的基础上,提出害虫治理要从“被动应急控制”转变为内部助增的“主动促进自然调控”的新理念,创新多种天敌昆虫协同控制多种害虫的“网式协同调控”新途径,建立一个自我维持并可有效降低害虫种群水平的农业生态系统.未来的研究应针对“天敌昆虫调控害虫的内在机制”与“天敌昆虫在农业生态系统中持续发挥作用的生态学基础”等关键科学问题,从基因、个体、种群、群落和生态系统不同层次,重点开展:1)天敌昆虫寄生和捕食害虫的行为与适应机制;2)天敌昆虫大量繁育的营养与生殖生理基础;3)寄生性天敌昆虫与寄主互作的免疫机制;4)天敌昆虫协同控害的生态学机制;5)天敌昆虫可持续利用的生物防治新模式等方面的研究. 相似文献
6.
7.
东北农业大学农学院吴研、王振营(中国农科院植保研究所)、赵长山等植保研究工作人员在转基因作物给人类带来经济效益的今天,对此课题进行了试验研究,发现转基因抗虫作物对靶标害虫有很好的控制作用。对捕食性天敌和寄生天敌及其种群数量的影响为其安全评价的重要内容。[第一段] 相似文献
8.
9.
天敌是影响害虫种群动态的重要因素。一般认为天敌对害虫作用的方式,主要是通过直接的捕食或寄生。事实上,天敌还可以通过捕食或寄生过程中产生的"威吓"等非直接致死效应(Non-lethal effects)或胁迫作用(Stress),影响着害虫的生长发育、繁殖。有时这种天敌存在的非直接致死效应对害虫产生的负面影响甚至比天敌对害虫的直接捕食作用还强。显然,评价天敌作用时,除了计算天敌对害虫的直接捕食或寄生的效率,还应考虑天敌存在时对害虫的非直接致死效应。本文基于作者及前人的研究,分别论述了捕食性天敌、寄生性天敌对害虫的非直接致死效应,解析了环境变化对天敌非直接致死效应的影响,探讨了这种非直接致死效应的可能机制,提出了未来的研究发展方向。 相似文献
10.
11.
烟粉虱Bemisia tabaci Gennadius是一种广泛分布于世界各地的多食性害虫,对我国多个省市区的农作物和观赏植物造成了严重的危害。化学杀虫剂的大量使用在杀伤天敌的同时使烟粉虱产生了不同程度的抗性,防治越来越困难;相较于化学防治,在不同地区筛选有效的天敌对烟粉虱进行生物防治是对烟粉虱进行有效控制的重要方法。我国报道的捕食性天敌共计26科109种,寄生性天敌共计2科59种。烟粉虱防治过程中由于单一的防治效果不理想,联合多个天敌资源的利用是增加对烟粉虱的生物防治效果的重要手段。本文通过对我国烟粉虱捕食性和寄生性天敌种类系统全面的整理,同时对烟粉虱优势种天敌中的单种或者多种组合利用后对烟粉虱的的控害潜能进行综述,以期为烟粉虱天敌昆虫种类的筛选和实现高效的生物防治提供科学依据。 相似文献
12.
烟草害虫天敌及其自然控制作用 总被引:8,自引:0,他引:8
介绍了云南省烟草主要害虫天敌资源和天敌昆虫的自然控制作用。在云南省烟田内 ,控制烟草害虫发生的生物因子大致可归纳为寄生性和捕食性两大类。充分发挥自然因素的生态调控作用 ,对保护利用天敌、维护烟田生态平衡、提高害虫综合治理效果、保护生态环境都有重要意义 相似文献
13.
14.
福州郊区小菜蛾天敌种类调查 总被引:7,自引:0,他引:7
1994-1999年对福州郊区小菜蛾的天敌种类进行了调查,发现寄生性天敌6种,捕食性天敌18种。并对最为常见的菜蛾绒茧蜂Cotesia plutellae与小菜蛾幼虫的田间消长动态进行了系统观察。 相似文献
15.
16.
Evolution of pesticide resistance in 24 apple pest and natural enemy species was simulated with a computer model. Population
ecology parameters were varied among species while physiological, biochemical and genetic assumptions were held constant.
There was good agreement between the model's predictions and observed historical patterns of azinphosmethyl resistance among
pests and natural enemies. Correspondence between predicted and observed was improved by assuming that natural enemies evolved
resistance only after their prey/hosts became resistant, but not by assuming greater initial susceptibility in natural enemies.
Results suggest that ecological factors may be important in determining rates of resistance evolution.
This is paper no. 2843 of the Hawaii Institute of Tropical Agriculture & Human Resources journal series, and no. 7245 of the
Oreg. Agric. Exp. Sta. journal series. 相似文献
17.
Athayde Tonhasca Jr. 《Entomologia Experimentalis et Applicata》1993,69(1):83-90
This study evaluated the effects of agroecosystem diversification through no-tillage and strip intercropping on the abundance
of natural enemies of soybean (Glycine max Merrill) herbivores. Twenty-four plots (289 m2 each) were arranged in a randomized complete block design for a 3 by 2 factorial experiment. Factors were cropping systems
(corn monoculture, soybean monoculture, and strip intercropping of corn and soybean) and tillage systems (no-tillage and conventional
tillage). Natural enemies were sampled during 1988, 1989 and 1990 by sweep net, suction net (D-Vac), pitfall traps and quadrat
samples. Analyses of variance indicated that of 15 taxa analyzed, most foliage-inhabiting natural enemies were significantly
more abundant in intercropping than in monoculture plots, whereas soil-inhabiting natural enemies had higher numbers in no-tillage
plots than conventional tillage plots. Therefore, the results support the theory of greater abundance of natural enemies in
more complex agroecosystems. Better environmental conditions in diversified treatments was the possible reason for these results.
Corn in intercropping plots provided shade, reduced wind speed, alternate food, and possibly higher humidity and lower temperatures
for soybean natural enemies. A similar effect was likely cuased by the stubble and weeds, in no-tillage plots. 相似文献
18.
19.
菜豆田两种潜叶蝇和主要天敌生态位研究 总被引:8,自引:0,他引:8
从生态位研究角度出发 ,采用 Hurlbert( 1978)生态位重叠和 L evins( 1968)生态位宽度指标 ,对严重危害菜豆的两种潜叶蝇 :美洲斑潜蝇 L iriomyza sativae Blanchard和豌豆潜叶蝇 Phytomyza atricor-nis Meig与主要天敌在时间和空间维度上的生态位重叠和生态位宽度作了定量分析。评价了天敌对猎物的时间及空间跟随作用和控制效果。研究表明 :寄生蜂、蜘蛛、龟纹瓢虫、异色瓢虫对豌豆潜叶蝇有较强的跟随作用和控制效果 相似文献
20.
Records of crop damage caused by Bibionidae are reviewed together with evidence for their beneficial activities, natural enemies and control methods. Bibionids are sporadic and infrequent pests. Although grass and cereals are most vulnerable, a wide range of crops is attacked. Damage is most severe after grass or when plants are under stress. The presence of organic matter during oviposition increases the likelihood of damaging populations. Many natural enemies exist but their impact on adult or larval populations has not been quantified. Given the pattern of attacks and lack of approved insecticides, cultural control methods are more appropriate than chemical. The role of adult bibionids in pollination and of larvae involved in soil processes could be of greater importance than any damage caused by the group. 相似文献