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1.
ABSTRACT. 1. Significantly more eggs were laid by adult female pine beauty moths ( Panolis flammea (D&S)) on previously undefoliated lodgepole pine ( Pinus contorta Douglas) saplings than on those which had been partially defoliated the year before.
2. The larval weights, mean relative growth rates and survival rates of P.flammea were lower on defoliated trees than on undefoliated trees.
3. Marked and significant differences between the monoterpene profiles of the shoot cortical oleoresin of defoliated and undefoliated trees were linked to oviposition preferences in P.flammea.
4. Differences occurred between the levels of soluble tannins in previously defoliated and undefoliated trees.
5. The results are discussed in relation to earlier work on insect-induced changes in plants, and the significance of inter-provenance differences in lodgepole pine response is assessed.  相似文献   
2.
Summary The idea of trade-offs among antiherbivore defences in plants is examined using data from a South American blackberry (Rubus bogotensis). Two distinct morphs of R. bogotensis, one with glandular trichomes and one without, were compared with respect to leaf toughness, number of prickles and prickle length. The two morphs were sympatric and grew under similar environmental conditions. The morph lacking trichomes had significantly tougher leaves and also tended to have more and longer prickles. Bioassay showed that Ithomiid larvae fed to a lesser extent on tough leaves than on more tender ones. Correlations between antiherbivore defences within each phenotype revealed three significant or almost significant negative relationships. The comparisons support the hypothesis that trade-offs exist among antiherbivore defences.  相似文献   
3.
Abstract.
  • 1 The possibility of interactions between leaf-miners in the genus Eriocrania and Coleophora serratella L. on birch (Betula pendula Ehrh. and B.pubescens Roth.) was studied via: (i) co-occurrence patterns on random samples of leaves; (ii) palatability of Eriocraniidae-mined leaves to C.serratella, in laboratory and field preference tests.
  • 2 In the field, C.serratella and Eriocrania spp. fed on common leaves less frequently than expected by chance. This result is consistent with, and could be explained by, the avoidance of mined leaves shown by C.serratella in most of the feeding trials.
  • 3 Avoidance was not observed at the between-tree level, i.e. the number of leaves mined by each type of insect was unrelated. However, when tree species was taken into account, an inverse distribution was observed: mine abundance was higher for Eriocrania spp. on B.pubescens, whereas for C.serratella it was higher on B.pendula.
  • 4 B.pubescens leaves mined by Eriocrania spp. had consistently higher phenolic contents and were better at precipitating proteins than unmined leaves. These induced chemical changes could explain the reduced preference shown by C.serrate1la for Eriocrania mined leaves.
  • 5 We speculate about the evolution of adult host-plant selection shown by these insects in response to potential larval interactions.
  相似文献   
4.
Summary Structural features of marine macrophytes are generally believed to act as defences against herbivores by reducing the ability of herbivores to consume the plants. Thallus form and calcification in particular have been considered structural defences that act by reducing the probability of consumption of tissue by herbivores. Studies directly measuring the mechanical resistance of a variety of marine algae (tropical and temperate) to herbivores of two important feeding types, rasping herbivores (docoglossan limpets) and a biting herbivore (an herbivorous crab), do not support this hypothesis. I suggest that thallus form and calcification may play a more important role in minimizing the impact of herbivores by reducing the probability of subsequent tissue loss due to herbivore-induced damage. For some algal species, tissue lost subsequent to herbivore damage may greatly exceed loss due to direct consumption by herbivores. I suggest that calcification and thallus properties resulting in preferential tear directions reduce the probability of tissue loss subsequent to herbivore damage rather than prevent herbivores from removing tissue as has been suggested in the past.  相似文献   
5.
David W. Kikuchi  William L. Allen  Kevin Arbuckle  Thomas G. Aubier  Emmanuelle S. Briolat  Emily R. Burdfield-Steel  Karen L. Cheney  Klára Daňková  Marianne Elias  Liisa Hämäläinen  Marie E. Herberstein  Thomas J. Hossie  Mathieu Joron  Krushnamegh Kunte  Brian C. Leavell  Carita Lindstedt  Ugo Lorioux-Chevalier  Melanie McClure  Callum F. McLellan  Iliana Medina  Viraj Nawge  Erika Páez  Arka Pal  Stano Pekár  Olivier Penacchio  Jan Raška  Tom Reader  Bibiana Rojas  Katja H. Rönkä  Daniela C. Rößler  Candy Rowe  Hannah M. Rowland  Arlety Roy  Kaitlin A. Schaal  Thomas N. Sherratt  John Skelhorn  Hannah R. Smart  Ted Stankowich  Amanda M. Stefan  Kyle Summers  Christopher H. Taylor  Rose Thorogood  Kate Umbers  Anne E. Winters  Justin Yeager  Alice Exnerová 《Journal of evolutionary biology》2023,36(7):975-991
Prey seldom rely on a single type of antipredator defence, often using multiple defences to avoid predation. In many cases, selection in different contexts may favour the evolution of multiple defences in a prey. However, a prey may use multiple defences to protect itself during a single predator encounter. Such “defence portfolios” that defend prey against a single instance of predation are distributed across and within successive stages of the predation sequence (encounter, detection, identification, approach (attack), subjugation and consumption). We contend that at present, our understanding of defence portfolio evolution is incomplete, and seen from the fragmentary perspective of specific sensory systems (e.g., visual) or specific types of defences (especially aposematism). In this review, we aim to build a comprehensive framework for conceptualizing the evolution of multiple prey defences, beginning with hypotheses for the evolution of multiple defences in general, and defence portfolios in particular. We then examine idealized models of resource trade-offs and functional interactions between traits, along with evidence supporting them. We find that defence portfolios are constrained by resource allocation to other aspects of life history, as well as functional incompatibilities between different defences. We also find that selection is likely to favour combinations of defences that have synergistic effects on predator behaviour and prey survival. Next, we examine specific aspects of prey ecology, genetics and development, and predator cognition that modify the predictions of current hypotheses or introduce competing hypotheses. We outline schema for gathering data on the distribution of prey defences across species and geography, determining how multiple defences are produced, and testing the proximate mechanisms by which multiple prey defences impact predator behaviour. Adopting these approaches will strengthen our understanding of multiple defensive strategies.  相似文献   
6.
A population of cyclomorphic Bosmina coregoni was studied in Lake Östersjön, southwestern Sweden and results from field samples collected in 1988, 1989, 1990 and 1991 are presented. Animals collected in summer have remarkably higher carapace and prolonged antennule compared to what we call the normal morph. In 1991 the extreme morph reach its maximum body length, body height and antennule length in July to September. The occurrence of the extreme morph coincide with the hatching of the predaceous cladoceran Leptodora kindtii.The two morphs fluctuate in abundance and in relation to each other. In early spring only the normal morph occurred in the samples followed by a period of about two months when the two morphs were found together, in July only the extreme morph was found. In September the two morphs were again present in the lake. As has been shown for other cladoceran, the conspicuous carapace and antennule could be an adaptive response that decreases mortality due to invertebrate predation. Spectacular features like these are likely also accompanied by some sort of costs.  相似文献   
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Background and Aims

Invasive plants can be released from specialist herbivores and encounter novel generalists in their introduced ranges, leading to variation in defence among native and invasive populations. However, few studies have examined how constitutive and induced indirect defences change during plant invasion, especially during the juvenile stage.

Methods

Constitutive extrafloral nectar (EFN) production of native and invasive populations of juvenile tallow tree (Triadica sebifera) were compared, and leaf clipping, and damage by a native specialist (Noctuid) and two native generalist caterpillars (Noctuid and Limacodid) were used to examine inducible EFN production.

Key results

Plants from introduced populations had more leaves producing constitutive EFN than did native populations, but the content of soluble solids of EFN did not differ. Herbivores induced EFN production more than simulated herbivory. The specialist (Noctuid) induced more EFN than either generalist for native populations. The content of soluble solids in EFN was higher (2·1 times), with the specialist vs. the generalists causing the stronger response for native populations, but the specialist response was always comparable with the generalist responses for invasive populations.

Conclusions

These results suggest that constitutive and induced indirect defences are retained in juvenile plants of invasive populations even during plant establishment, perhaps due to generalist herbivory in the introduced range. However, responses specific to a specialist herbivore may be reduced in the introduced range where specialists are absent. This decreased defence may benefit specialist insects that are introduced for classical biological control of invasive plants.  相似文献   
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