Showing papers on "Plant tolerance to herbivory published in 1991"
TL;DR: Four sources of evidence are used to support the Plant Vigor Hypothesis that many herbivore species feed preferentially on vigorous plants or plant modules, as opposed to the Plant Stresshypothesis arguing that stressed plants ae beneficial to herbivores.
Abstract: Four sources of evidence are used to support the Plant Vigor Hypothesis that many herbivore species feed preferentially on vigorous plants or plant modules, as opposed to the Plant Stress Hypothesis arguing that stressed plants ae beneficial to herbivores. Evidence includes patterns of within-plant species utilization by galing insects where females select large plant modules and larvae survive better than on smaller modules. Independent evidence concerns patterns of herbivory between plant species habitually growing in rich resource environments which are heavily utilized, compared with low-resource adapted species. A third source of evidence is the forestry literature in which many cases are known of most attacks by insect herbivores occurring on young and open-grown trees
1,110 citations
TL;DR: For example, this paper found that small marine herbivores that live on the plants they consume often selectively eat seaweeds that are chemically defended from fishes, and these small herbivore dramatically reduce their susceptibility to predation by associating with host plants that are noxious to fishes.
Abstract: Small marine herbivores that live on the plants they consume often selectively eat seaweeds that are chemically defended from fishes. Their feeding is unaffected or stimulated by the plant metabolites that deter fishes, and these small herbivores dramatically reduce their susceptibility to predation by associating with host plants that are noxious to fishes. Ecological similarities between these small marine herbivores and numerous terrestrial insects suggest that herbivorous insects also may have evolved a preference for toxic plants because this diminishes their losses to predators, parasites and pathogens. Although marine and terrestrial plants and herbivores evolved in strikingly different environments, the ease of experimentation in some marine systems makes them ideal for addressing certain questions of fundamental importance to both terrestrial and marine workers.
90 citations
TL;DR: It is argued that induced production of plant chemicals evolved first as a direct defense against herbivores, and that the attractive function likely evolved secondarily.
Abstract: Herbivore-induced plant chemical responses are usually considered direct defenses against the herbivorous attackers. Recent findings show that a third topic level can be involved as well. Herbivore-injured plants release relatively large amounts of volatiles that are attractive to natural enemies of the herbivores. The host-searching behavior of the generalist parasitoid Cotesia marginiventris is mediated by such plant produced volatiles. Since plant and entomophage both profit from this interaction it has been suggested that the plant responses serve to recruit the entomophages. Here we argue that induced production of plant chemicals evolved first as a direct defense against herbivores, and that the attractive function likely evolved secondarily. Results of a plant palatability experiment are given to provide preliminary support for a defensive function. Plants that were induced to release volatiles that are known to be attractive to the parasitoid became less palatable to the herbivore beet armyworm.
45 citations
TL;DR: It is concluded that the best use of biotechnology in crop protection is to reintroduce chemical diversity into crop plants to counteract insect defensive evolution by keeping the selection pressure as variable as possible.
Abstract: The use, as opposed to the procurement, of transgenic crop plants is discussed in this paper. Transgenic crop plants must not be used until appropriate strategies for their use have been designed and not before crop plants with a variety of insect defenses have been developed. The use of a crop plant with a single defense will pose as strong a selection pressure as the use of a single synthetic insecticide, since insect herbivores are able to evolve effective counter-defenses. The defenses of insects in natural plant-insect associations and with regard to synthetic insecticides are described to demonstrate that there is nothing unique about insecticide resistance. It is the inevitable alternative to local extinction in response to a persistent and predictable selection pressure. Plants counteract insect defensive evolution by keeping the selection pressure as variable as possible. This leads to the conclusion that the best use of biotechnology in crop protection is to reintroduce chemical diversity into crop plants.
22 citations