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  • 2000-2004  (3)
  • 1990-1994  (12)
  • 1980-1984  (3)
  • 1
    Digitale Medien
    Digitale Medien
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Entomology 46 (2001), S. 703-727 
    ISSN: 0066-4170
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract This review points out the problem of processing multiple sensory inputs and provides evidence that generalists suffer a disadvantage compared with specialists with respect to efficiency of host plant choice and discrimination. The specialists' mechanisms for improved efficiency are discussed as well as some of the processes that may be selected to increase processing efficiency in generalists. The fitness consequences of differences in efficiency of specialists and generalists are pointed out. One of the major disadvantages for generalists is the increase in vulnerability to ecological risks, especially risks imposed by various natural enemies. Efficiency-related factors are indicated as previously underestimated elements that could influence host affiliations including diet breadth and changes in host plant use.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Journal of comparative physiology 186 (2000), S. 13-19 
    ISSN: 1432-1351
    Schlagwort(e): Key words Catalpol ; Grammia ; Gustation ; Iridoid glycoside ; Phagostimulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Caterpillars of the arctiid moth, Grammia geneura, are polyphagous, but species of Plantago are amongst their preferred food plants. A neuron in the medial styloconic sensillum on the galea has been shown to have a general phagostimulatory function. Experiments with binary mixtures and cross-adaptation have demonstrated that it responds to some sugars, to several amino acids, and also to catalpol. Catalpol is a plant secondary compound in Plantago and a phagostimulant for the caterpillars. The possible significance of combining sensitivity to nutrient compounds with sensitivity to a secondary compound is discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 54 (1990), S. 53-56 
    ISSN: 1570-7458
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé 6 composés secondaires végétaux: sinigrine, acide caféique, acide vanilique, linamarine, amygdaline et gramine, très répandus dans la nature, se montrent phagodissuasifs pour le spécialiste de graminées, Locusta migratoria. C'est pourquoi leurs effects après ingestion sont examinés sur tous les stades larvaires. Pour mettre en évidence une influence éventuelle, les expériences sont réalisées avec une ration alimentaire correspondant à la moitié de celle qu'absorbent des criquets consommant à volonté. Dans un cas, l'addition d'un composé secondaire dans le régime alimentaire (amygdaline) produit une augmentation significative du taux de croissance. La discussion porte sur les conséquences évolutives de ces résultats.
    Notizen: Abstract Six plant secondary compounds that are quite widespread in nature were shown to be deterrent to the grass specialist, Locusta migratoria. These were then tested for their post-ingestional effects over the whole of the last larval instar. To enhance the possibility of an effect, experiments were conducted where the food ration was less than half of that normally taken by insects feeding ad libitum. In no case was there any indication of a detrimental effect or any trend suggesting one. In one case (amygdalin) there was a significant increase in growth rate with the addition of the secondary compound to the diet. The evolutionary implication of these findings are discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 54 (1990), S. 117-124 
    ISSN: 1570-7458
    Schlagwort(e): Antifeedant ; Manduca sexta ; host plant choice ; preference feeding behavior
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Nous avons examiné au moyen des expériences de choix, les effects dissuasifs des composés secondaires de plantes non-hôtes des chenilles de M. sexta Johan. Des disques de fibres de verre ou des rondelles de feuilles de tabac ont été traités chimiquement, aux concentrations à peu près naturelles. Sur les 30 substances examinées sur les disques de fibres de verre, 6 ont été répulsives pour des chenilles élvées sur aliment artificiel. Quand l'examen est effectué avec des rondelles de feuilles de tabac, seul un produit est encore répulsif. Aucun effet répulsif n'est observé quand des chenilles élevées sur tabac sont mises en présence de substances associées à des rondelles de feuille de tabac. Ces résultats suggèrent que le maintien d'un spectre d'hôtes limité chez les chenilles de M. sexta ne repose pas sur l'évitement des plantes non-hôtes par suite de leurs substantes dissuasives, mais sur l'attraction et la stimulation provoquées par les hôtes.
    Notizen: Abstract We tested the deterrent effects of non-host plant secondary compounds on Manduca sexta Johan. larvae, in choice tests. Treatment chemicals were applied, at approximately natural concentrations to either glass fiber or tobacco leaf disks. Of 30 compounds tested on glass fiber disks, with artificial diet reared larvae, 6 were deterrent. When the 6 deterrent chemicals were tested on tobacco leaf disks only one was still deterrent. No deterrent effects were observed when tobacco reared larvae were tested with chemicals applied to tobacco leaf disks. The results suggest that maintenance of restricted host range in M. sexta larvae relies not on avoidance of non-hosts due to deterrence but on attraction and stimulation to feed on hosts.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 54 (1990), S. 125-130 
    ISSN: 1570-7458
    Schlagwort(e): Manduca sexta ; deterrence ; toxicity ; oligophagy ; plant secondary compound
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Les effets qui suivent l'ingestion de 7 produits secondaires de plantes non-hôtes ont été examinés sur des chenilles de M. sexta. Ces substances avaient été choisies pour la diversité de leurs effets sur le comportement alimentaire lors d'expériences de courte durée: 4 avaient montré des effets dissuasifs variés, 3 n'en avaient pas présenté. On a enduit des feuilles fraiches de leur plante-hôte (Nicotania tabacum) des différentes substances à raison d'à peu près 1% du poids sec. Seule une substance a réduit les performances des chenilles. Ces résultats ont été discutés en fonction de l'absence de relation entre dissuation et toxicité dans l'évolution des défenses chez les plantes.
    Notizen: Abstract Seven non-host plant secondary compounds were tested for their post-ingestional effects on larvae of Manduca cesta Johan. The compounds were selected for their range of effects on feeding behavior in short-term tests: four showed different levels of deterrence while three were not deterrent. Insects were dosed by coating fresh leaves of their food plant (tobacco) with particular compounds at concentrations of 1% dry weight. Only one compound had detrimental effects on larval performance. The results are discussed in the context of the lack of correlation between deterrence and toxicity and the evolution of plant defenses.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 64 (1992), S. 289-292 
    ISSN: 1570-7458
    Schlagwort(e): Deterrence ; oral dosing ; toxicity ; diet breadth ; Hypera brunneipennis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A variety of plant secondary compounds, several of which are quite widespread in nature were tested for their deterrence to the specialist coleopteran Hypera brunneipennis (Boheman) in short-term behavioral assays. The compounds were nicotine, quinine, sparteine, hordenine, linamarin, amygdalin, sinigrin, morin, juglone, chlorogenic acid, digitonin, mimosine, diosgenin, rutin and ursolic acid. Nine of these were then tested for their post-ingestional effects over one to two weeks of adult life, using fecundity as a measure of the effects. In only one case was there any indication of a detrimental effect or any trend suggesting one. The evolutionary implications of these findings are discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 60 (1991), S. 19-28 
    ISSN: 1570-7458
    Schlagwort(e): Schistocerca americana ; rutin ; grasshopper ; phagostimulant ; phenolic
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Rutin was demonstrated to be a phagostimulant for the grasshopper Schistocerca americana across a very wide concentration range. The effect was not maintained over a period of days if the insects had already ingested a large amount, but when individuals were given different concentrations on disks as supplements to their lettuce diet, they tended to self select a moderate quantity on a daily basis. In long term experiments on food utilization and growth rates using artificial diet, no beneficial effects of rutin could be demonstrated. Ingested rutin was absorbed and some of it deposited in the cuticle. Most was excreted as the aglycone quercetin. The possible functional significance of the phagostimulatory effect is discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 61 (1991), S. 247-253 
    ISSN: 1570-7458
    Schlagwort(e): Schistocerca ; dietary mixing ; compensatory feeding ; learning ; flavors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Dietary mixing by nymphs of Schistocerca americana was studied in the laboratory using artificial diet cakes. Individuals were given either two different inadequate but complementary diet cakes or two adequate and identical ones. When unique flavors (coumarin or NHT) were added to the diet cakes, insects given the inadequate diet treatment switched between cakes more than insects exposed to the adequate diets. This was not the case when no identifying flavors were added.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    ISSN: 1572-8889
    Schlagwort(e): Schistocerca ; grasshopper ; learning ; aversion ; novelty ; polyphagy ; dietary mixing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Schistocerca americanasixth-instar nymphs were examined for a change in diet acceptance, in which insects experiencing an unfavorable diet subsequently become predisposed to eat relatively less of that diet and more of diets with a novel flavor than they would had they previously fed on a more adequate diet. Insects were pretreated for 4 h on either low-protein (2 % wet wt) or higherprotein (4%) artificial diets flavored with a plant secondary compound (tomatine or rutin). They were then offered, in choice or no-choice tests, the lowprotein diet with the familiar or a novel (tomatine, rutin, or NHT) flavor. When tomatine was the familiar and rutin the novel flavor in a no-choice test, the insects previously fed low-protein diets took relatively long meals on the novel and relatively short meals on the familiar diets compared with the insects that had previously eaten higher-protein diets. A similar, but in this case considerably less pronounced and statistically nonsignificant, pattern existed in the reciprocal design experiment in which rutin was the familiar and tomatine the novel flavor. Similarly, insects fed low-protein diets flavored with rutin subsequently showed an increased relative preference for the novel flavor (NHT) in a choice test, compared with the high protein-pretreated insects. It is concluded that insects fed protein-deficient diets may subsequently show a preference for novel foods through different mechanisms, the importance of which may differ in different circumstances.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Journal of insect behavior 8 (1994), S. 161-180 
    ISSN: 1572-8889
    Schlagwort(e): plant secondary compound ; Schistocerca americana ; diets ; food mixing ; feeding behavior ; feeding patterns
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Plant secondary compounds can prevent feeding by phytophagous insects or, if ingested, can be poisonous to them. Less attention has been paid to the additional effects they have on feeding behavior when they are only weakly deterrent or not deterrent at all. Experiments were carried out on the generalist grass-hopperSchistocerca americana. Individuals were presented either with two cakes of high-quality artificial food with a single deterrent compound added or with two cakes, each with a different added deterrent compound. The deterrents consisted of single plant secondary compounds that were either marginally or strongly deterrent. There were profound differences in feeding behavior between those individuals given identical and those given different cake types, including longer feeding bouts on single cakes when a choice of different cake types was available. The behavioral effects demonstrate that the presence of secondary compounds in one food can influence the patterns of feeding on other available foods and suggest that such chemicals could impact foraging activities in a complex manner.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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