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1.
    
Compared with mycorrhizal relationships, the relationships between mycoheterotrophic plants and insects have rarely been studied. Here we report a previously unknown tripartite interaction among an endangered mycoheterotrophic orchid, an orchid‐feeding fly, and a parasitoid wasp. The flowers and stems of Eulophia zollingeri were heavily attacked by Japanagromyza tokunagai (Sasakawa) (Diptera: Agromyzidae), and the parasitoid wasp Gronotoma guamensis (Yoshimoto) (Hymenoptera: Figitidae) was reared from these J. tokunagai individuals. Considering the high infestation rate of J. tokunagai, G. guamensis could be important in suppressing the J. tokunagai population, and positively affect the reproductive success of E. zollingeri.  相似文献   

2.
    
It is important to understand the interactions between orchids and their herbivores, especially considering the rarity of most orchids and the potential negative effects of pests on orchid reproduction. Here, we report the infestation of leaves of Cephalanthera spp. orchids by Parallelomma vittatum (Scathophagidae) in Japan. The present study represents the first report of P. vittatum on orchid hosts in Asia.  相似文献   

3.
1. The megadiverse herbivores and their host plants are a major component of biodiversity, and their interactions have been hypothesised to drive the diversification of both. 2. If plant diversity influences the diversity of insects, there is an expectation that insect species richness will be strongly correlated with host‐plant species richness. This should be observable at two levels (i) more diverse host‐plant groups should harbour more species of insects, and (ii) the species richness of a group of insects should correlate with the richness of the host groups it uses. However, such a correlation is also consistent with a hypothesis of random host use, in which insects encounter and use hosts in proportion to the diversity of host plants. Neither of these expectations has been widely tested. 3. These expectations were tested using data from a species‐rich group of insects – the Coccidae (Hemiptera). 4. Significant positive correlations were found between the species richness of coccid clades (genera) and the species richness of the host‐plant family or families upon which the clades occur. On a global scale, more closely related plant families have more similar communities of coccid genera but the correlation is weak. 5. Random host use could not be rejected for many coccids but randomisation tests and similarity of coccid communities on closely related plant families show that there is non‐random host use in some taxa. Overall, our results support the idea that plant diversity is a driver of species richness of herbivorous insects, probably via escape‐and‐radiate or oscillation‐type processes.  相似文献   

4.
    
The psilid fly Chyliza vittata is a leaf miner or stem borer of some orchids in Europe and Japan but few studies on its behavior have been published. Here I describe aspects of the reproductive behavior of the species infesting Gastrodia elata, a leafless orchid. Male mate‐seeking behavior occurred on flowering G. elata plants that were attractive to egg‐laden females, and indeed copulation was observed. Although two or more males were commonly seen on an orchid stem without interaction, males occasionally reacted aggressively toward other males. Females laid eggs on the flowers, floral buds or bracts as well as into the flowers, using their “ovipositor”. Almost all orchids studied eventually produced mature capsules; therefore G. elata seemed to suffer limited damage from infestation by C. vittata. Information regarding a natural enemy and pupation habits is also provided.  相似文献   

5.
    
Although most crane fly larvae consume decaying plant materials and their associated microorganisms, all Libnotes species investigated so far are known to be xylophilous insects. Here we report the novel herbivorous feeding ecology of Libnotes puella. We found that L. puella larvae consumed the fruits or seeds of three unrelated plants, Mitrastemon yamamotoi (Mitrastemonaceae), Balanophora tobiracola (Balanophoraceae) and Barringtonia racemosa (Lecythidaceae). The larvae live within dense tubes formed by their feces fastened by their mucous excretions at the final stage, and they pupate within such tubes. This is the first detailed documentation of the fruit‐ and seed‐feeding habit of crane flies.  相似文献   

6.
7.
    
Genetically engineered (GE) rice lines expressing Lepidoptera‐active insecticidal cry genes from the bacterium Bacillus thuringiensis (Bt) have been developed in China. Field surveys indicated that Bt rice harbours fewer rice planthoppers than non‐Bt rice although planthoppers are not sensitive to the produced Bt Cry proteins. The mechanisms underlying this phenomenon remain unknown. Here, we show that the low numbers of planthoppers on Bt rice are associated with reduced caterpillar damage. In laboratory and field‐cage experiments, the rice planthopper Nilapavata lugens had no feeding preference for undamaged Bt or non‐Bt plants but exhibited a strong preference for caterpillar‐damaged plants whether Bt or non‐Bt. Under open‐field conditions, rice planthoppers were more abundant on caterpillar‐damaged non‐Bt rice than on neighbouring healthy Bt rice. GC–MS analyses showed that caterpillar damage induced the release of rice plant volatiles known to be attractive to planthoppers, and metabolome analyses revealed increased amino acid contents and reduced sterol contents known to benefit planthopper development. That Lepidoptera‐resistant Bt rice is less attractive to this important nontarget pest in the field is therefore a first example of ecological resistance of Bt plants to nontarget pests. Our findings suggest that non‐Bt rice refuges established for delaying the development of Bt resistance may also act as a trap crop for N. lugens and possibly other planthoppers.  相似文献   

8.
    
Host specialization plays a key role in the extreme diversification of phytophagous insects. Whereas proximate mechanisms of specialization have been studied extensively, their consequences for species divergence remain unclear. Preference for, and performance on hosts are thought to be a major source of divergence in phytophagous insects. We assessed these major components of specialization in two moth species, the European corn borer (ECB) and the Adzuki bean borer (ABB), by testing their oviposition behaviour in different conditions (choice or no‐choice set‐ups) and their performances, by reciprocal transplant at the larval stage on the usual host and an alternative host plant. We demonstrated that both ABB and ECB have a strong preference for their host plants for oviposition, but that relative larval performances on the usual host and an alternative host differed according to the experiment and the trait considered (weight or survival). Finally, we show for the first time that the preference for maize in ECB conceals a strong avoidance of mugwort. The differences in performance, attraction and avoidance between ECB and ABB are discussed in the light of the underlying mechanisms and divergence process.  相似文献   

9.
    
The ability of non‐crop plants to support complete development of insect pests is an important factor for determining the impact of those plants on resistance management programs for transgenic crops. We assessed the effect of one physical factor, plant stem diameter, on the ability of plants to support full development of the European corn borer (ECB), Ostrinia nubilalis Hübner (Lepidoptera: Crambidae), the target pest of transgenic Bt‐corn. In the field, European corn borer larvae were significantly more likely to tunnel and survive in plants with larger stem diameters. Larvae were 40× more likely to survive on corn, the largest plant tested, compared to many of the smaller plants. In the laboratory, larvae were more likely to survive in and less likely to abandon the largest diet‐filled artificial stems that varied only in stem diameter. In conditions simulating those that an ECB larvae would encounter upon abandoning a host, larvae survived up to three weeks and were able to locate corn as a new host with a significantly higher frequency than would be expected if they were foraging randomly. These results indicate that the probability of ECB larval survival to maturity on a plant other than corn is relatively low and thus these smaller stemmed non‐corn plants may not make a substantial contribution to the pool of susceptible adults. Conversely, since more mature larvae are not as susceptible as neonates, any larvae that partially develop on non‐corn plants and subsequently colonize Bt‐corn may not be exposed to a lethal dose of the toxin. Since some proportion of the individuals that survive could be partially resistant heterozygotes the presence of non‐corn host plants could facilitate the development of resistant ECB populations.  相似文献   

10.
植物的诱导抗虫性   总被引:72,自引:8,他引:72       下载免费PDF全文
娄永根  程家安 《昆虫学报》1997,40(3):320-331
植物对植食性昆虫的抗性可包括两个方面,即植物的组成抗性(constitutiveresistance)和诱导抗性(inducedresistance)。组成抗性是指植物在遭受植食性昆虫进攻前就已存在的抗虫特性;而诱导抗性是指植物在遭受植食性昆虫进攻后所表现出来的一种抗虫特性[1,2]。根据作用世代的不同,诱导抗性又分为迅速的诱导抗性(rapidlyinducedre-sistance,RIR)和滞后的诱导抗性(delayedinducedresistance,DIR)。前者是指对当前世代的植食性昆虫的影响,而后者是指对后续的1~几个世代的植食性昆虫的影响[2]。研究植物的诱导抗虫性,不仅能在…  相似文献   

11.
    
Invasive plants that displace native floral communities can cause changes to associated invertebrate species assemblages. Using a mini‐review of the literature and our own data we add to the still considerable debate about the most effective methods for testing community‐level impacts by invasive species. In endangered saltmarshes of southeast Australia, the non‐native rush Juncus acutus L. is displacing its native congener J. kraussii Hochst., with concurrent changes to floral and faunal assemblages. In two coastal saltmarshes, we tested the hypothesis that the ability to detect differences in the invertebrate assemblage associated with these congeneric rushes depends on the microhabitat of the plant sampled. We used three sampling methods, each targeting specific microhabitats: sweep netting of the plant stems, vacuum sampling of the plant tussock, and vacuum sampling of the ground directly below the plants. Over 3800 individuals and 92 morphospecies were collected across four main taxa: gastropods, crustaceans, hexapods and arachnids. Detection of differences in invertebrate density, richness and composition associated with native compared with non‐native rushes was dependent on the microhabitat sampled and these differences were spatially variable. For example, at one saltmarsh the stems and tussock of J. acutus had a lower density and richness of total invertebrates and hexapods than those of the native J. kraussii. In contrast, crustaceans on the ground were in greater abundance below J. acutus than J. kraussii. This study demonstrates that on occasions where overall differences in the assemblage are not detected between species, differences may become apparent when targeting different microhabitats of the plant. In addition, separately targeting multiple microhabitats likely leads to a greater probability of detecting impacts of invasion. Comparing the invertebrate assemblage without differentiating between or sampling an array of microhabitats can fail to determine the impact of invasive species. These results highlight that a combination of methods targeting different microhabitats is important for detecting differences within the invertebrate community, even for phylogenetically related species.  相似文献   

12.
为了解红树植物植食性昆虫在不同季节、不同潮位和不同寄主植物上的种类、密度差异和主要特点及其对红树植物树冠层所造成的影响,进而分析植食性昆虫对红树植物群落演替的影响,在山口红树林保护区设置5个断面,分别于雨季(7月)和旱季(2月),在每个断面的高潮位(H)、中潮位(M)和低潮位(L)针对不同植物抽样,统计叶片被食率,记录植食性昆虫的种类和密度。植食性昆虫共有23种,其中鳞翅目有13种,半翅目8种,鞘翅目1种,直翅目1种,真螨目1种。主要昆虫种类有海榄雌瘤斑螟(Ptyomaxia sp.)、毛颚小卷蛾(Lasiognatha cellifera)、白囊袋蛾(Chalioides kondonis)、广翅蜡蝉(Ricania sp.)、潜叶蛾(Phyllocnistis sp.)和蛎盾蚧(Lepidosaphes sp.)。雨季和旱季的密度均为广翅蜡蝉较高(7.31头·枝-1);不同断面红树植物叶片被食率旱季为C5>C2≥C3≥C1,雨季为C5>C2≥C3≥C1>C4;不同潮位的叶片被食率旱季为中潮位≥高潮位>低潮位,雨季为中潮位>低潮位≥高潮位;不同树种的叶片...  相似文献   

13.
虫瘿—昆虫与植物互作的奇特产物   总被引:1,自引:0,他引:1  
虫瘿是昆虫刺激产生的植物不正常组织。造瘿昆虫几乎能在高等植物的所有类群中产生形态各异的虫瘿,甚至能在同一种植物上形成多种形态不一的虫瘿。虫瘿形成的机制仍不清楚,普遍认为是昆虫控制了虫瘿的形成,但植物细胞也参与了虫瘿形成的调控。为了探索这一神秘的领域,科学家们已经对昆虫的刺激物以及植物的反应作了大量的研究,未来工作的难点将是如何把二者联系起来。  相似文献   

14.
植物与植食性昆虫之间存在着复杂的化学相互作用。一方面,当遭受植食性昆虫为害时,植物能识别植食性昆虫相关分子模式,触发早期信号事件和激素信号转导途径,并由此引起转录组与代谢组重组、直接和间接防御化合物含量升高,最后提高对植食性昆虫的抗性。另一方面,植食性昆虫也能识别植物的防御反应,并能通过分泌效应子、选贮、解毒以及降低敏感性等反防御措施抑制或适应植物的化学防御。深入剖析植物与植食性昆虫的化学互作,不仅可在理论上丰富对昆虫与植物互作关系的理解,而且可在实践上为作物害虫防控新技术的开发提供重要的理论与技术指导。  相似文献   

15.
【目的】本文探究了大豆食心虫Leguminirora glycinioorella(Mats.)Obraztsov进入滞育以后体内糖类、脂质和水分含量的变化,以及不同寄主植物和滞育诱导期温度对大豆食心虫体内糖类、脂质和水分含量的影响。【方法】通过蒽酮硫酸法和氯仿甲醇分离法测定了滞育前后、以大豆Glycine max(L.)Merr和野大豆Glycine soja Sieb.et Zucc.两种植物为寄主以及不同滞育诱导温度下的大豆食心虫体内脂质、水分、总糖、糖原和海藻糖的含量,结果利用SPSS17.0数据分析软件进行分析。【结果】进入滞育阶段的大豆食心虫体内脂质、总糖、海藻糖和糖原含量显著增加,含水量显著下降。以大豆为寄主的大豆食心虫在滞育阶段体内水分含量、总糖和糖原含量较野大豆寄主的高,海藻糖含量较野大豆的低,差异均显著。不同滞育诱导温度下的大豆食心虫体内生化物质含量基本一致。【结论】滞育前后大豆食心虫体内各种生化物质变化明显,以栽培大豆为寄主和以野大豆为寄主的大豆食心虫体内生化物质含量不同,而滞育诱导温度对大豆食心虫体内生化物质含量影响不大。  相似文献   

16.
    
The traditional explanation for the exceptional diversity of herbivorous insects emphasizes host shift as the major driver of speciation. However, phylogenetic studies have often demonstrated widespread host plant conservatism by insect herbivores, calling into question the prevalence of speciation by host shift to distantly related plants. A limitation of previous phylogenetic studies is that host plants were defined at the family or genus level; thus, it was unclear whether host shifts predominate at a finer taxonomic scale. The lack of a statistical approach to test the hypothesis of host‐shift‐driven speciation also hindered studies at the species level. Here, we analyze the radiation of leaf cone moths (Caloptilia) associated with maples (Acer) using a newly developed, phylogeny‐based method that tests the role of host shift in speciation. This method has the advantage of not requiring complete taxon sampling from an entire radiation. Based on 254 host plant records for 14 Caloptilia species collected at 73 sites in Japan, we show that major dietary changes are more concentrated toward the root of the phylogeny, with host shift playing a minor role in recent speciation. We suggest that there may be other roles for host shift in promoting herbivorous insect diversification rather than facilitating speciation per se.  相似文献   

17.
HuanJQ WeiZM 《Cell research》2001,11(2):149-155
Immature embryos of rice varieties "Xiushuill" and "Chunjiang 11" precultured for 4d were infected and transformed by Agrobacterium tumefaciens strain EHA101/pExT7 (containing the spider insecticidal gene). The resistant calli were transferred onto the differentiation medium and plants were regenerated. The transformation frequency reached 56% approximately 72% measured as numbers of Geneticin (G418)-resistant calli produced and 36% approximately 60% measured as numbers of transgenic plants regenerated, respectively. PCR and Southern blot analysis of transgenic plants confirmed that the T-DNA had been integrated into the rice genome. Insect bioassays using T1 transgenic plants indicated that the mortality of the leaffolder (Cnaphalocrasis medinalis) after 7d of leaf feeding reached 38% approximately 61% and the corrected mortality of the striped stem borer (Chilo suppressalis) after 7d of leaf feeding reached 16% approximately 75%. The insect bioassay results demonstrated that the transgenic plants expressing the spider insecticidal protein conferred enhanced resistance to these pests.  相似文献   

18.
    
Lizard beetles (Erotylidae, Languriinae, Languriini) are known as stem borers of plants and contain agricultural pests and endangered species, but their species–host plant associations have been poorly documented. Here we investigated the larval host plants of two species of the genus Tetraphala Strum, T. collaris (Crotch) and Tetraphala sp. occurring in Taiwan. Females of T. collaris excavated living leafstalks and stems of the herbaceous dicot, Sambucus chinensis (Adoxaceae) using their mandibles for oviposition. We observed the eggs and early-instar larvae inside and nearby oviposition holes and late-instar larvae inside stems, suggesting that T. collaris uses living leafstalks and stems of S. chinensis as oviposition substrate and the larvae tunnel into stems with feeding on the tissues. Similarly, females of Tetraphala sp. excavated living leafstalks of the fern, Pteris wallichiana (Pteridaceae) using their mandibles for oviposition. We observed the eggs and early-instar larvae inside and nearby oviposition holes. When reared in laboratory, a larva reached adulthood inside the leafstalk. These results indicated that Tetraphala sp. uses living leafstalks of Pt. wallichiana as oviposition substrate and the larvae complete their development within. This study revealed that the genus Tetraphala contains both fern- and dicot-users during larval period. Further study is needed to clarify the evolutionary process of host plant use of languriines. Additionally, the host plant list of Languriini is provided.  相似文献   

19.
    
Numerous studies have reported that larval experience can affect subsequent host plants selection and future oviposition decisions of many different species, but the investigation of pre‐imaginal experiences on host preference of adults has rarely been tested for soil‐dwelling insects. In this study, we present evidence that larval feeding experience can affect adult host preference in the onion maggot, Delia antiqua. By rearing D. antiqua on different host plants, we were able to examine the role of the natal host of different generations and the effect of larval density on host‐choice behaviour. We also performed bioassays by means of switched host treatment to evaluate the host‐selection principle. Choice bioassays among the three host species demonstrated that D. antiqua females preferred to oviposit on their natal host in each generation and host‐switching treatments. Additionally, increasing larval density could intensify this ovipositional preference on the natal host. The overall results showed that host preference of female D. antiqua is determined by larval experience and density. These findings also add support for the controversial Hopkins’ host‐selection principle.  相似文献   

20.
The ability of non-crop plants to support complete development of insect pests is an important factor for determining the impact of those plants on resistance management programs for transgenic crops. We assessed the effect of one physical factor, plant stem diameter, on the ability of plants to support full development of the European corn borer (ECB), Ostrinia nubilalis Hübner (Lepidoptera: Crambidae), the target pest of transgenic Bt-corn. In the field, European corn borer larvae were significantly more likely to tunnel and survive in plants with larger stem diameters. Larvae were 40× more likely to survive on corn, the largest plant tested, compared to many of the smaller plants. In the laboratory, larvae were more likely to survive in and less likely to abandon the largest diet-filled artificial stems that varied only in stem diameter. In conditions simulating those that an ECB larvae would encounter upon abandoning a host, larvae survived up to three weeks and were able to locate corn as a new host with a significantly higher frequency than would be expected if they were foraging randomly. These results indicate that the probability of ECB larval survival to maturity on a plant other than corn is relatively low and thus these smaller stemmed non-corn plants may not make a substantial contribution to the pool of susceptible adults. Conversely, since more mature larvae are not as susceptible as neonates, any larvae that partially develop on non-corn plants and subsequently colonize Bt-corn may not be exposed to a lethal dose of the toxin. Since some proportion of the individuals that survive could be partially resistant heterozygotes the presence of non-corn host plants could facilitate the development of resistant ECB populations.  相似文献   

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