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1.
稻田生态系统中杂草地捕食性节肢动物群落研究   总被引:5,自引:0,他引:5  
采用吸虫器法采样,对稻田生态系统中杂草地捕食性节肢动物天敌群落物种多样性、结构动态等进行了系统的研究。在杂草地生境中采集到73种捕食性节肢动物,其中55种为捕食性蜘蛛,18种为捕食性昆虫。在冬春闲期,杂草地生境的捕食性节肢动物物种多样性和单位面积内的个体数量较高。水稻移栽后,杂草地中的捕食性节肢动物种群迁进稻田,为稻田提供天敌移居者,杂草地生境中的捕食性天敌物种数减少,单位面积内的个体数量降低;水稻成熟后、夏闲期始及冬闲期始,杂草地接纳从稻田中迁出的天敌种群,捕食性天敌物种数和单位面积内的个体数量呈上升趋势。杂草地为保护稻田捕食性天敌,提供了一个良好的庇难所。  相似文献   

2.
昆虫作为变温动物类群,极易遭受高温胁迫的影响。研究高温胁迫对植食性昆虫的影响,可为气候变暖背景下农林害虫的种群动态监测及地理适生区预测提供重要理论依据。笔者从植食性昆虫个体、种间互作关系、种群及群落3个层面,综述了高温胁迫对植食性昆虫影响的国内外进展。研究发现,高温胁迫会对植食性昆虫个体的生长发育、繁殖及生理生化带来负面效应,但昆虫自身也会进化出一系列基于形态、行为及基因表达的热胁迫响应机制。高温胁迫对寄主植物、天敌、共生微生物的影响也能够通过种间互作传递给植食性昆虫,并导致寄主植物-植食性昆虫-天敌3级营养关系发生变化。同时,高温胁迫还能通过影响昆虫个体及种间关系,间接影响昆虫的种群动态、种群多样性及其生态功能,并可能导致植食性昆虫的种群大爆发或衰退。最后,笔者认为此领域未来研究方向为:在个体层面上,应优化高温胁迫处理方式并综合考虑干旱和降水等环境因子,开展农林害虫种群的长期野外监测,应注重高温胁迫对昆虫参与生长发育繁殖功能基因的影响;在种间关系层面上,应关注高温胁迫对昆虫关联的复杂多样的食物网及互作体系的影响;此外,应结合高温胁迫对不同昆虫种类自身生理特性和行为模式的影响,阐明温度升高对昆虫群落的影响。  相似文献   

3.
Low host specificity of herbivorous insects in a tropical forest   总被引:20,自引:0,他引:20  
Novotny V  Basset Y  Miller SE  Weiblen GD  Bremer B  Cizek L  Drozd P 《Nature》2002,416(6883):841-844
Two decades of research have not established whether tropical insect herbivores are dominated by specialists or generalists. This impedes our understanding of species coexistence in diverse rainforest communities. Host specificity and species richness of tropical insects are also key parameters in mapping global patterns of biodiversity. Here we analyse data for over 900 herbivorous species feeding on 51 plant species in New Guinea and show that most herbivorous species feed on several closely related plant species. Because species-rich genera are dominant in tropical floras, monophagous herbivores are probably rare in tropical forests. Furthermore, even between phylogenetically distant hosts, herbivore communities typically shared a third of their species. These results do not support the classical view that the coexistence of herbivorous species in the tropics is a consequence of finely divided plant resources; non-equilibrium models of tropical diversity should instead be considered. Low host specificity of tropical herbivores reduces global estimates of arthropod diversity from 31 million (ref. 1) to 4 6 million species. This finding agrees with estimates based on taxonomic collections, reconciling an order of magnitude discrepancy between extrapolations of global diversity based on ecological samples of tropical communities with those based on sampling regional faunas.  相似文献   

4.
Tylianakis JM  Tscharntke T  Lewis OT 《Nature》2007,445(7124):202-205
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5.
Lill JT  Marquis RJ  Ricklefs RE 《Nature》2002,417(6885):170-173
Patterns of association between herbivores and host plants have been thought to reflect the quality of plants as food resources as influenced by plant nutrient composition, defences, and phenology. Host-plant-specific enemies, that is, the third trophic level, might also influence the distribution of herbivores across plant species. However, studies of the evolution of herbivore host range have generally not examined the third trophic level, leaving unclear the importance of this factor in the evolution of plant-insect herbivore interactions. Analysis of parasitoid rearings by the Canadian Forest Insect Survey shows that parasitism of particular Lepidoptera species is strongly host-plant-dependent, that the pattern of host-plant dependence varies among species of caterpillars, and that some parasitoid species are themselves specialized with respect to tree species. Host-plant-dependent parasitism suggests the possibility of top-down influence on host plant use. Differences in parasitism among particular caterpillar-host plant combinations could select for specialization of host plant ranges within caterpillar communities. Such specialization would ultimately promote the species diversification of Lepidoptera in temperate forests with respect to escape from enemies.  相似文献   

6.
For numerous taxa, species richness is much higher in tropical than in temperate zone habitats. A major challenge in community ecology and evolutionary biogeography is to reveal the mechanisms underlying these differences. For herbivorous insects, one such mechanism leading to an increased number of species in a given locale could be increased ecological specialization, resulting in a greater proportion of insect species occupying narrow niches within a community. We tested this hypothesis by comparing host specialization in larval Lepidoptera (moths and butterflies) at eight different New World forest sites ranging in latitude from 15 degrees S to 55 degrees N. Here we show that larval diets of tropical Lepidoptera are more specialized than those of their temperate forest counterparts: tropical species on average feed on fewer plant species, genera and families than do temperate caterpillars. This result holds true whether calculated per lepidopteran family or for a caterpillar assemblage as a whole. As a result, there is greater turnover in caterpillar species composition (greater beta diversity) between tree species in tropical faunas than in temperate faunas. We suggest that greater specialization in tropical faunas is the result of differences in trophic interactions; for example, there are more distinct plant secondary chemical profiles from one tree species to the next in tropical forests than in temperate forests as well as more diverse and chronic pressures from natural enemy communities.  相似文献   

7.
呼和浩特市行道树国槐上的蚧虫主要种类为枣球蜡蚧(Eulecanium gigantea)和槐花球蚧(E.kuwanai),通过研究其天敌有两种,分别为球蚧蓝绿跳小蜂(Blastothrix sericae)和北京举肢蛾(Beijing utila).对这两种天敌的形态特征、生活史、生活习性及与蚧虫的关系进行了研究.  相似文献   

8.
研究人工干预的灯光诱杀对潮汕地区橄榄树虫害的影响,建立考虑灯光诱杀橄榄树虫害的捕食者-食饵模型,并分析模型的动力学性态,给出了两个边界平衡点和正平衡点的存在及稳定条件.通过博弈论分析利用灯光诱杀和天敌捕杀害虫的结果,发现同时利用灯光诱杀和天敌捕杀害虫效果最佳.通过数值模拟发现在橄榄树虫害的防治中不仅要利用天敌,还要加入人工干预的灯光诱杀,可以避免害虫数量突然爆发,有效控制害虫数量,同时有利于保护橄榄树上生物的多样性.  相似文献   

9.
扰动对天敌有多食性模型稳定性的影响   总被引:1,自引:0,他引:1  
本文主要讨论了扰动对天敌具有多食性模型 x_1=x_1(r_1-a_1y), x_2=x_2(r_2-a_2y), y=y(-r_3+b_1x_1+b_2x_2)稳定性的影响。利用Liapunov函数得到了昆虫种类内部的密度制约,将促使昆虫与天敌系统进一步稳定化,进而得出同一食饵水平上的竞争是不稳定化的结论。其中后一种情况与J.M,Smith的结论完全一致。  相似文献   

10.
昆虫与天敌模型的稳定性研究,已有文献是用经典的Logistic与Lotka-Vol terra方程来刻划的。最近Cui与Lawson[2]建立了以营养动力学为基础的新模型。本文应用这个新模型描述昆虫与天敌的模型,并讨论其稳定性。  相似文献   

11.
本文报道了新疆棉田螨类群落中的叶螨科(Tetranychidae)亚群落营养结构。从采到的标本中已鉴定出棉叶螨5种,天敌26种。初步探索了叶螨亚群落的食物网络关系,比较了棉田不同施药水平与天敌数量关系。  相似文献   

12.
2010—2012年对福建省番石榴园的介壳虫及其天敌进行调查,结果表明为害番石榴的介壳虫有8种,隶属4科7属。其中橘臀纹粉蚧发生较重,堆蜡粉蚧、银毛吹绵蚧、咖啡黑盔蚧次之;其余4种零星为害。番石榴园中蚧类天敌资源丰富,以瓢虫、草蛉为主;保护和利用这些天敌,对番石榴蚧类的防治有重要意义。  相似文献   

13.
Low beta diversity of herbivorous insects in tropical forests   总被引:1,自引:0,他引:1  
Recent advances in understanding insect communities in tropical forests have contributed little to our knowledge of large-scale patterns of insect diversity, because incomplete taxonomic knowledge of many tropical species hinders the mapping of their distribution records. This impedes an understanding of global biodiversity patterns and explains why tropical insects are under-represented in conservation biology. Our study of approximately 500 species from three herbivorous guilds feeding on foliage (caterpillars, Lepidoptera), wood (ambrosia beetles, Coleoptera) and fruit (fruitflies, Diptera) found a low rate of change in species composition (beta diversity) across 75,000 square kilometres of contiguous lowland rainforest in Papua New Guinea, as most species were widely distributed. For caterpillars feeding on large plant genera, most species fed on multiple host species, so that even locally restricted plant species did not support endemic herbivores. Large plant genera represented a continuously distributed resource easily colonized by moths and butterflies over hundreds of kilometres. Low beta diversity was also documented in groups with differing host specificity (fruitflies and ambrosia beetles), suggesting that dispersal limitation does not have a substantial role in shaping the distribution of insect species in New Guinea lowland rainforests. Similar patterns of low beta diversity can be expected in other tropical lowland rainforests, as they are typically situated in the extensive low basins of major tropical rivers similar to the Sepik-Ramu region of New Guinea studied here.  相似文献   

14.
本文是重庆市郊瓜类蔬菜昆虫群落研究结果的第一部分,主要报道瓜类昆虫落(包括蛛形纲和软体动物门中的一些有害生物及天敌,下同)的组成和结构,初步查明对瓜类蔬菜有直接或间接危害的动物有53种,分属于3纲,14目中的32个科;天敌38种,涉及2纲,9目中的21个科,另外还有传粉昆虫和杂食性昆虫各1种,分属于2个科,在初步弄清群落内物种间营养关系的基础上,用营养物种的概念探讨了不同营养物种数,不同类型链节数,链节总数与物种数之间的关系,表明瓜类昆虫群落属于发育不成熟,结构较为简单的群落,本文还同时应用基于食物网映射矩阵的匹配系数和基于物种及其多度的群落系数对5种瓜类昆虫群落相似性进行了比较。  相似文献   

15.
访花传粉是显花植物和动物(主要是昆虫、鸟类和蝙蝠)协同进化的结果,已知显花植物85%是由昆虫传媒授粉的。双翅目寄蝇科是一类重要的访花传粉昆虫,突颜寄蝇亚科和寄蝇族等成虫最常见于各类显花植物上。报告了我国常见的访花传粉寄蝇科4亚科18族54属119种物种名录,它们在农林牧业生产、植物保护、害虫生物控制及维护生态系统平衡稳定中意义重大,但还没有被认识和利用。  相似文献   

16.
国槐蚧虫种类鉴定、危害及防治的研究   总被引:3,自引:0,他引:3  
通过对呼和浩特市行道树国槐(Sophora japonica)上的蚧虫进行调查和观察,确定其主要种类为枣球蜡蚧(Eulecanium gigantea)和槐花球蚧(E.kuwanai).并对其生活史、生活习性、天敌、危害程度和防治进行了研究.枣球蜡蚧和槐花球蚧在国槐上混合发生,且枣球蜡蚧多于槐花球蚧,比例为9/1.其天敌有两种:球蚧蓝绿跳小蜂(Blastothrix sericae)和北京举肢蛾(Beijing utila).用喷雾、注干和浇根三种方法进行防治试验,筛选出防治国槐蚧虫的最佳施药方法和最佳打药时间.  相似文献   

17.
<正>海南省尖峰岭热带林自然保护区昆虫的垂直分布明显,昆虫区系属东洋界,其中许多种类是热带区域或热带山地雨林的特有种,这些昆虫具有区系稳定、种类多而种群数量少、鳞翅目丰富、广腰亚目贫乏等特色;受季风和生物同步现象的影响,森林昆虫每年都有二个发生高峰。热带森林害虫的防治,应在生态学原理的指导下,保护好现有的原始林,对已破坏了的原始林地区,需用封山育林、营造混交林等林业措施来改善森林结构,建立起新的生态平衡,从而对害虫达到自然控制的目的。  相似文献   

18.
根据近几年来在石河子垦区采集、鉴定的昆虫标本和该地区植保部门提供的农业昆虫名录,从其中取其分布资料比较完整的715种农业昆虫,并结合本地区的地形地势、气候条件、农作物布局和农业昆虫发生的特点,对石河子垦区农业昆虫的区系结构和生态分布进行了初步的分析,进而提出本区的农业昆虫区系划分的五级区(即小区)的划分意见:1)北部莫索湾——下野地垦区;2)中部十户滩——石总场——安集海垦区;3)南部紫泥泉垦区。同时,作者还对每个小区的农业昆虫优势种、生态特点进行了概述,介绍其在测报与综合防治中的意义。  相似文献   

19.
深圳福田红树林害虫及其发生原因   总被引:16,自引:0,他引:16  
报道1994和1999年福田红树林害虫,其它昆虫及蜘蛛的调查结果,1994年在红树林采到昆虫96种及蜘蛛7种,其中天敌昆虫37种,占已知种类的35.8%;1999年采用昆虫53种及蜘蛛5种,其中天敌昆虫13种,占已知种类24%,对地林造成为害和具有潜在危害的种类也有所增加,Shannon-Wiener多样性指数(H),均匀度指数(J)和丰富度指数分别为:H1994=2.47,H1999=1.64,J1994=0.54,J1999=0.42,D1994=16.1,D1999=9.37,分析结果显示,1999年红树林生态环境比1994年急剧恶化,这是红树林害虫发生的根本原因。  相似文献   

20.
本文记录了西昌农田害虫天敌寄生性昆虫96种,捕食性昆虫81种。  相似文献   

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