啄木鸟对森林害虫生态控制作用浅析

啄木鸟Picidae是杨树蛀干天牛Cerambycidae的重要天敌之一,在控制天牛危害方面具有显著优势,同时对其他森林害虫也有较好的控制作用.本文在对啄木鸟生活习性和特征的观察、对杨树蛀干天牛及其他森林害虫生态控制作用的研究的基础上,阐明了用啄木鸟对杨树蛀干天牛及其他森林害虫实施生态控制,是杨树蛀干天牛工程治理和其他森林害虫防治的有效途径之一,具有广泛的发展前景.     

西安城区环境中释放花绒寄甲成虫对光肩星天牛的生物防治效果评价

光肩星天牛Anoplophora glabripennis(Motsch.)是我国西北及华北地区危害杨树、柳树等树种的主要蛀干害虫,较难防治.花绒寄甲Dastarcus helophoroides(Fairmaire)是光肩星天牛等林木蛀干害虫的重要天敌昆虫.我国近儿年来已开始广泛利用花绒寄甲对光肩星天牛进行生物防治,...     

A-3型松褐天牛引诱剂诱虫谱研究

2002～2004年,在广州地区应用A-3型松褐天牛Monochamus alternatus Hope(鞘翅目Coleoptera天牛科Cerambycidae)引诱剂诱捕鞘翅目昆虫,结果表明:A-3型松褐天牛引诱剂具有较广的诱虫谱,可以诱捕到鞘翅目中10个科48种昆虫;松树的主要蛀干害虫是松褐天牛、赤梗天牛Arhopalus unicolor Ganhan、马尾松角胫象Shirahoshizo patruelis Voss、松瘤象Hyposipalus gigas Fabricius和松纵坑切梢小蠢Tomicus piniperda Linnaeus等小蠹虫;进一步分离所诱捕的松褐天牛及其他松树主要蛀干害虫携带松材线虫Bursaphelenchus xylophilus Nickle的情况,发现松褐天牛与赤梗天牛均携带松材线虫,其中松褐天牛是松材线虫病最重要的传播媒介.     

天敌昆虫利用信息化学物质寻找寄主或猎物的研究进展

应用天敌昆虫控制害虫是传统生物防治中的主要内容。信息化学物质是天敌昆虫远距离向寄主或猎物栖息地进行定向,以及近距离对寄主或猎物进行定位所依赖的重要信号。综述了能够引诱天敌昆虫的信息化学物质的产生、分类、作用、异同及背景,并介绍了天敌昆虫对信息化学物质的行为反应和特异性。同时,对这类物质在生物防治中的应用及前景作了介绍与探讨。对不同营养层的种间化学通讯作为研究协同进化时的重要参考也作了简要介绍。     

寄生性天敌蒲螨研究进展

蒲螨属Pyemotes具有特殊的生活史和形态特征,是多种害虫的体外寄生性天敌。蒲螨属的种按照形态等特点分为2个组,分别为小蠹蒲螨组(Pyemotes scolyti group)和球腹蒲螨组(Pyemotes ventricosus group)。国内外对蒲螨毒素的研究较多,已知其属于昆虫神经毒素,能使寄主昆虫永久性麻痹,有些种类还能引起人类和动物皮炎。对一些种类蒲螨的毒素组成成分、毒素基因重组技术等进行研究,对蒲螨毒素基因的优化和重组仍将是进一步研究的热点。作为一类很有潜能的害虫天敌资源,蒲螨应用方面的报道还较少,国外集中在麦蒲螨对仓储害虫和红火蚁的防治方面;我国有利用小蠹蒲螨防治小蠹虫的报道,近年来防治双条杉天牛取得成功,表明其用于防治钻蛀性害虫特别是蛀干害虫和地下害虫前景良好,因此,应对蒲螨蒲螨寄主谱、寄主选择机理、寄生机理等进行深入研究。     

天敌昆虫在我国林业害虫生物防治上的研究进展

长期以来,一些林业本地害虫和外来入侵害虫对我国森林生态系统造成了严重损害或威胁,而天敌昆虫作为一类有效的自然调控因子,对这些害虫的种群抑制发挥了重要作用。本文以日本松干蚧、松突圆蚧、湿地松粉蚧、美国白蛾、椰心叶甲、红脂大小蠹6种重要入侵种以及杨圆蚧、白蜡窄吉丁、松墨天牛、光肩星天牛、栗山天牛、松毛虫等多种本地重要害虫为例,介绍了近50年来利用天敌昆虫进行生物防治的研究状况,对我国林业害虫生物防治实践中存在的问题进行了分析,并对未来天敌昆虫资源的开发与利用等方面进行了展望。     

虫害诱导蔬菜作物挥发物的研究进展

蔬菜作物释放的虫害诱导植物挥发物(Herbivore-induced plant volatiles,HIPVs)是蔬菜作物受害虫胁迫后产生的一类启动防御反应的化合物,可以作为蔬菜作物的对外重要信息交流媒介和防御措施实施前体.蔬菜作物通过释放HIPVs来增强自身防御反应、调节昆虫行为和向邻近作物发出"预警信号",从而直接或间接地抵御植食性昆虫危害.近年来,有关HIPVs的研究已成为昆虫行为学与化学生态学的关注热点.本文系统综述了虫害诱导蔬菜作物挥发物类别、释放特性、生态功能及应用等方面,以期梳理和阐释HIPVs在蔬菜-害虫二级营养结构以及蔬菜-害虫-害虫天敌三级营养结构的化学生态网络中的重要化学信号功能,并对未来该方向的研究进行展望.     

转基因抗虫植物-植食性昆虫-天敌间化学通讯的研究进展

植物或昆虫释放的化学信息物质在植物-植食性昆虫-天敌三级营养层信息通讯中发挥重要作用.这种生物间的信息交流形成信息网,调节生物种内和种间行为,支撑和维持植物和昆虫群落的组成和结构.转基因抗虫植物的应用可能会影响三级营养层间的化学信息通讯,进而干扰生物群落结构和农田生态系统稳定性.该方面已在全球范围内引起了转基因抗虫作物环境安全研究者的关注.本文对植物-植食性昆虫-天敌间化学信息通讯进行了简要概括;分析和归纳了转基因抗虫作物的种植对植物和节肢动物间化学通讯的潜在影响及相关机制;讨论了该领域当前的研究进展和未来研究前景.以期促进我国科学家在该领域的研究,加深对转基因抗虫作物群落结构动态潜在影响的理解.     

信息化合物对昆虫行为的影响

本文综述了来自寄主植物的挥发性物质和同种昆虫或异种昆虫释放的各种信息素及两者的协同作用的信息化合物对昆虫行为的影响。特别强调了寄主植物的气味物质和昆虫信息素协同作用在昆虫寻找寄主、求偶、交配及天敌在寄主识别过程中的重要地位。昆虫对寄主植物的识别是由于识别了植物气味的由一定组分、按照严格比例组成的化学指纹图。昆虫信息素与植物挥发性物质相结合为昆虫寻找求偶、交配场所提供更复杂或更全面的信息。许多昆虫只有在寄主植物或寄主植物气味存在时 ,才能释放性或聚集信息素。天敌在寄主识别、搜索及定位等一系列过程中 ,来自寄主的食料、寄主本身及两者的互作的信息化合物起重要的作用。研究信息化合物对昆虫行为的影响可以探索昆虫各种行为的内在机理 ,更好的了解寄主—昆虫—天敌三层营养关系的相互作用 ,对利用天然活性化合物防治害虫及生物防治提供理论依据     

水稻挥发性信息化合物对昆虫的作用

植物挥发性化合物是联系植物、害虫和天敌间3层营养关系的关键信息因子。是害虫防治理论与实践的基础．首先,介绍了水稻挥发性信息化合物的基本化学特征及其在植食性昆虫和天敌昆虫寄主选择中的作用;其次,分析了水稻挥发性信息化合物的产生与作用机制及其生态学功能和水稻挥发性信息化合物研究中存在的问题;最后,展望了水稻挥发性信息化合物的研究前景．对水稻挥发性化合物的更进一步研究有两个方向,一是对存在于水稻体内,启动相关代谢途径的小分子信号物质的生理生化和分子生物学特性进行研究;二是研究捕食性节肢动物对信息化合物的接收、识别和学习等行为及与这些行为相关的生理生化和分子基础．     

小蠹虫对针叶类寄主树木的选择危害机制

小蠹虫对寄主植物的选择是一个非常复杂的过程,也是近年来小蠹虫生态学研究的一个热门话题。文章对国内外小蠹虫寄主搜寻、寄主识别,以及适宜寄主选择等机制等方面的最新研究成果进行了系统报道。     

Roles of bacteria in the bark beetle holobiont – how do they shape this forest pest?

Bark beetles are well‐known forest pests, some species inducing massive attacks on trees, resulting in the devastation of entire woodlands. Bark beetles are associated with microorganisms, forming an entity known as ‘holobiont’. Beetles and fungi are the best‐studied members of this multipartite symbiosis. However, recent studies have shown that bacteria may play important roles in the bark beetle holobiont, such as providing certain nutrients, promoting the growth of beneficial fungi, detoxifying the environment by lowering the levels of phenolic compounds synthesised by the host tree or by inhibiting the growth of antagonistic fungi whereas some bacterial symbionts have the potential to kill beetles under certain conditions. Therefore, bacteria probably greatly affect the life cycle of bark beetles; hence, more research is needed to clarify the extent to which a bacterial associate is implicated in a bacterial bark beetle symbiosis and how much it determines host's performance. This review summarises all of the known activities of bacteria present in the bark beetle holobiont, indicates some important gaps in the knowledge of this symbiosis and provides some guidance for overcoming the difficulties in investigating this relationship in future studies.     

Ophiostomatoid fungi can emit the bark beetle pheromone verbenone and other semiochemicals in media amended with various pine chemicals and beetle-released compounds

Fungal volatile compounds can mediate fungal-insect interactions. Whether fungi can emit insect pheromones and how volatile chemicals change in response to chemicals the fungi naturally encounter is poorly understood. We analyzed volatiles emitted by Grosmannia clavigera (symbiont of the mountain pine beetle) and Ophiostoma ips (symbiont of the pine engraver beetle) growing in liquid media amended with compounds that the fungi naturally encounter: (−)-α-pinene, (+)-α-pinene, (−)-trans-verbenol, verbenone, or ipsdienol. Nine volatile compounds were identified among the fungal and amendment treatments. Volatiles qualitatively and quantitatively differed between fungal species and among amendment treatments. The bark beetle anti-aggregation pheromone (−)-verbenone was detected from both fungi growing in (−)-trans-verbenol-amended media. G. clavigera and O. ips can emit beetle pheromones and other beetle semiochemicals, suggesting that ophiostomatoid fungi could contribute to the chemical ecology of bark beetles. However, such contributions could be modulated by the presence of other environmental chemicals.     

An attack of Ips amitinus (Coleoptera: Curculionidae: Scolytinae) on arboretum in West Siberia: New host of invasive bark beetle among exotic conifers

Invasive populations of small spruce bark beetle Ips amitinus were first registered in 2019 in the southeast of Western Siberia. In natural stands of Siberian pine (Pinus sibirica Du Tour), several hundred hectares of outbreak foci of the alien bark beetle were identified. In 2020, a local focus of the bark beetle was found in the conifer collection in the arboretum “Kedr” of the Institute of Monitoring Climatic and Ecological Systems SB RAS, 30 km from Tomsk. The bark beetle caused the main damage to the collection of pines. I. amitinus colonized both host plants Scotch pine (Pinus sylvestris L.) and mountain pine (Pinus mugo Turra), which were previously known to it in the native range in Europe, and the local Siberian species Siberian pine (Pinus sibirica Du Tour), Siberian spruce (Picea obovata Ledeb.) and introduced Far Eastern Korean pine (Pinus koraiensis Sieb. et Zucc.). Demographic characteristics of I. amitinus studied on damaged trees indicate its high reproduction potential in Siberia. The bark beetle outbreak focus was suppressed; however, this plantation requires further annual monitoring of pest abundance and distribution, both to preserve the scientific dendroecological field station and to study the implementation of sential plant conception in relation to the invasion of I. amitinus.     

外来入侵林业害虫强大小蠹的侵袭以及相关信息化学物质

强大小蠹是入侵我国并造成很大危害的鞘翅目棘胫小蠹科大小蠹属树皮低干森林害虫。它能侵害多种针叶树和松树 ,能被寄主挥发物和其它小蠹虫的外激素所引诱。该文综述了强大小蠹的侵袭习性以及寄主挥发物、其它小蠹虫的外激素对强大小蠹的引诱和驱避作用。     

Threshold facilitations of interacting species

The dynamics of species interactions are of central importance for the understanding of ecological coexistence, community structure and the effects of biological invasions. Using bark beetles that colonize the same habitat as an example, we explore species interactions in a resource-based model system with positive feedback between insect abundance and resource availability. The net interspecies interaction was found to be highly dynamic and may alternate in time between competition and mutualism. When both bark beetle species were able to kill trees (“aggressive”), our simulations showed strong facilitations between beetle species. This may lead to escape from control by competition, and increase the frequency of outbreaks of tree-killing. The frequency of net positive interactions varied with interaction strengths and the relative aggressiveness of the species and was highest when both species were strongly aggressive; which predicts disastrous outbreaks if, e.g., the European spruce bark beetle Ips typographus and the North American spruce beetle Dendroctonus rufipennis should become interacting species due to introductions. In imbalanced pairs, the relatively less aggressive species was facilitated more often than the aggressive species. Net positive interactions did not occur for strongly inferior species, but their survival was an increasing function of interaction strength with aggressive species and availability of resources. The benefits for the inferior species in the model are consistent with the structure of one aggressive and several less aggressive or non-aggressive species, which is common in bark beetle communities in many parts of the world.     

Large carbon release legacy from bark beetle outbreaks across Western United States

Warmer conditions over the past two decades have contributed to rapid expansion of bark beetle outbreaks killing millions of trees over a large fraction of western United States (US) forests. These outbreaks reduce plant productivity by killing trees and transfer carbon from live to dead pools where carbon is slowly emitted to the atmosphere via heterotrophic respiration which subsequently feeds back to climate change. Recent studies have begun to examine the local impacts of bark beetle outbreaks in individual stands, but the full regional carbon consequences remain undocumented for the western US. In this study, we quantify the regional carbon impacts of the bark beetle outbreaks taking place in western US forests. The work relies on a combination of postdisturbance forest regrowth trajectories derived from forest inventory data and a process‐based carbon cycle model tracking decomposition, as well as aerial detection survey (ADS) data documenting the regional extent and severity of recent outbreaks. We find that biomass killed by bark beetle attacks across beetle‐affected areas in western US forests from 2000 to 2009 ranges from 5 to 15 Tg C yr^?1 and caused a reduction of net ecosystem productivity (NEP) of about 6.1–9.3 Tg C y^?1 by 2009. Uncertainties result largely from a lack of detailed surveys of the extent and severity of outbreaks, calling out a need for improved characterization across western US forests. The carbon flux legacy of 2000–2009 outbreaks will continue decades into the future (e.g., 2040–2060) as committed emissions from heterotrophic respiration of beetle‐killed biomass are balanced by forest regrowth and accumulation.     

Effectiveness of different lures for attracting Ips acuminatus (Coleoptera: Curculionidae: Scolytinae)

1. Ips acuminatus (the sharp-toothed bark beetle, STBB) is currently considered to be one of the most serious pests of Scots pine in many European countries. STBB management is among the most challenging tasks in pine forests; the development of methods for monitoring, predicting and managing outbreaks of this bark beetle is therefore crucial.
2. Pheromone-baited traps have been widely recommended as a valuable tool for the monitoring and mass trapping of bark beetles. Although different suppliers offer a variety of STBB lures, their effectiveness has rarely, if ever, been evaluated under natural conditions.
3. We evaluated the attractiveness of three commercially available and five experimental synthetic lures by comparing the numbers of STBBs captured in white, six-funnel traps. The studies were conducted in 2017–2019 in Poland, in Scots pine-dominated forests affected by STBB outbreaks.
4. Our study demonstrated significant differences in the effectiveness of the lures. The experimental lure produced by the Witasek company (Austria) and the recently marketed lure Acumodor Micro from Chemipan (Poland) were the most attractive to STBB. Among the least effective were two commercial lures (Acuwit and Acumodor), hitherto used in Central Europe.
5. The results will be useful in developing methods for the monitoring and management of STBB populations.

     

The effect of warmer winters on the demography of an outbreak insect is hidden by intraspecific competition

Warmer climates are predicted to increase bark beetle outbreak frequency, severity, and range. Even in favorable climates, however, outbreaks can decelerate due to resource limitation, which necessitates the inclusion of competition for limited resources in analyses of climatic effects on populations. We evaluated several hypotheses of how climate impacts mountain pine beetle reproduction using an extensive 9‐year dataset, in which nearly 10,000 trees were sampled across a region of approximately 90,000 km², that was recently invaded by the mountain pine beetle in Alberta, Canada. Our analysis supports the hypothesis of a positive effect of warmer winter temperatures on mountain pine beetle overwinter survival and provides evidence that the increasing trend in minimum winter temperatures over time in North America is an important driver of increased mountain pine beetle reproduction across the region. Although we demonstrate a consistent effect of warmer minimum winter temperatures on mountain pine beetle reproductive rates that is evident at the landscape and regional scales, this effect is overwhelmed by the effect of competition for resources within trees at the site level. Our results suggest that detection of the effects of a warming climate on bark beetle populations at small spatial scales may be difficult without accounting for negative density dependence due to competition for resources.     

A Host Creates an Enemy‐free Space for Mistletoes by Reducing Seed Predation Caused by a Woodboring Beetle: A Hypothesis

Parasitic plants rely on host plants for nutrition. The number of host species varies largely between groups, from single species or genus to hundreds of species. Relative abundance of the host and evolutionary history are the main requisites for parasitic plants to develop specificity to abundant hosts. In the present study, we suggest a novel mechanism by which a hemiparasitic mistletoe can develop local specificity mediated by its host. First, we describe a novel interaction in which a woodboring beetle (Hypothenemus obscurus) preys on mistletoe seeds (Psittacanthus plagiophyllus) attached to tree branches. This beetle preys more frequently on seeds deposited on branches of non‐host species than on branches of its unique local host species (53 percent on average vs. 26 percent respectively). We hypothesize that local host specificity for this mistletoe could be partly mediated by beetle‐host incompatibility, since the host offers a predation‐free space in which mistletoes have better chances to grow. Furthermore, that the exceptional gum exudates produced by this unique host species minimize beetle attacks on branches, thus reducing predation of mistletoe seeds. This novel tritrophic interaction opens an avenue for research on macroscopic host‐specificity mechanisms that occur at the level of the host bark and that have been poorly studied by plant ecologists.