Global ETD Search

1	Foliar nutrition: targeted fertilization to test herbivore preference Penner, Johan January 2014 (has links) Abstract The aim of this study was to increase knowledge of how plants as a whole respond to targeted fertilization and to refine the method of foliar nutrition fertilization. The experiment also aimed to test how herbivores respond when presented with a choice between fertilized and unfertilized Salix leaves in a feeding trial experiment. One major problem that arises when trying to alter the nutrient levels within a specific part of a plant is that adding fertilizer directly to the soil in which the plants grow will have a systemic effect on the plant, causing the plant physiology as a whole to change instead of just changing the properties of the plant part which the study focuses on. The approach chosen for this experiment is to target the leaves directly when applying the fertilizer and therefore try to avoid altering the rest of the plant. Fertilizer in the form of NH3NO4 was added to Salix leaves using a pipette and a brush at two different concentrations. When the leaves had been fertilized they were analyzed and used in a feeding trial experiment to study herbivore response to targeted fertilization. Once all data was analyzed statistically it became clear that both concentrations of the treatment had altered the nitrogen content within the leaves, however only the lower concentration had done so without altering the characteristics of the leaf. The data collected from the feeding trial displayed no statistical evidence for preference between the treated and control leaves in regard to amount consumed by the Phratora beetles, on the other hand when testing for egg laying preference 8/8 of egg clutches were laid on treated leaves. Foliar nutrition Salix viminalis Phratora vulgatissima Fertilization Feeding trial
2	Nutrient driven oviposition and food preference in terrestrial herbivorous insects - a choice experiment / Näringsstyrd äggläggning och födoval hos terrestra herbivora insekter - ett experiment Waara, Linnéa January 2016 (has links) The presence of competitors and predators as well as plant quality affect which plants an insect feed from. These factors affect food choice through the entire insect life cycle, and is especially important when it comes to nurturing larvae. Females oviposition choice sets the initial stage for larval growth and survival, and it is therefore predicted that there is a strong selection pressure to make them oviposit on the best plants possible. This study looks into the behavior of nutrient driven ovipositing and food choice in the beetles Phratora vitellinae and Lochmaea caprea by offering individuals ten leaves of Salix viminalis, one treated with extra nitrogen in order to increase the nutritional value, and four treated with extra carbon, which should lower the nutritional value. During the choice experiment, only two females of Phratora vitellinae oviposited, making it impossible to draw any conclusion regarding nutrient driven oviposition choice. However, data showed a preference for nitrogen treated leaves and an avoidance of untreated control leaves in almost every case when looking into the largest loss of area for leaves of each treatment. When analyzing the number of leaves of each treatment that is eaten per individual there was a slight preference for nitrogen treated leaves, even though the probability of nitrogen being ranked as most preferred in this case was almost zero. Carbon treated leaves and acetone treated control leaves were equally avoided. For Lochmaea caprea, females fed from a significantly larger numer of leaves than males did (t-test, t=1.86, p=0.0003). An ANOVA showed no significant difference in C:N ratio among leaf treatments (ANOVA, F=9.28E-07, p=0.99). Since plant C:N ratio most likely will increase continuously due to CO2 emissions, the effects an increased carbon concentration in plant tissues has on oviposition and food choice in herbivorous insects is something to look further into. More studies on this subject are therefore needed. Herbivore-plant interactions offspring survival Salix viminalis Phratora vitellinae Lochmaea caprea C:N ratio CO2 emissions
3	Die Weidenblattkäfer an Weiden und Pappeln im Kurzumtrieb Helbig, Christiane, Georgi, Richard, Müller, Michael 25 June 2013 (has links) (PDF) Während der letzten Jahre ist die mit Kurzumtriebsplantagen bestockte Fläche in Deutschland deutlich angestiegen. Derzeit geht man von etwa 5 000 ha aus [1]. Der Hauptteil dieser Flächen ist mit Pappeln bestockt, während Weiden einen geringeren Anteil einnehmen. In anderen Ländern wie Großbritannien oder Schweden ist das Verhältnis dagegen umgekehrt und es finden sich große, zusammenhängende Weidenkulturen. Hier tritt der Blaue Weidenblattkäfer (Phratora vulgatissima) schon seit Jahren als Hauptschadinsekt auf und verursacht die Entlaubung ganzer Plantagen. Auch in Deutschland ist der Blaue Weidenblattkäfer die am häufigsten vorgefundene Schadinsektenart an Weiden im Kurzumtrieb. Kurzumtriebsplantage Blattwespenlarven Phratora vulgatissima Blauer Weidenblattkäfer. Pappel Weiden Schädlinge SRC short rotation coppice pest poplar Salix willow ddc:630 rvk:ZC 78820
4	Die Weidenblattkäfer an Weiden und Pappeln im Kurzumtrieb Helbig, Christiane, Georgi, Richard, Müller, Michael January 2013 (has links) Während der letzten Jahre ist die mit Kurzumtriebsplantagen bestockte Fläche in Deutschland deutlich angestiegen. Derzeit geht man von etwa 5 000 ha aus [1]. Der Hauptteil dieser Flächen ist mit Pappeln bestockt, während Weiden einen geringeren Anteil einnehmen. In anderen Ländern wie Großbritannien oder Schweden ist das Verhältnis dagegen umgekehrt und es finden sich große, zusammenhängende Weidenkulturen. Hier tritt der Blaue Weidenblattkäfer (Phratora vulgatissima) schon seit Jahren als Hauptschadinsekt auf und verursacht die Entlaubung ganzer Plantagen. Auch in Deutschland ist der Blaue Weidenblattkäfer die am häufigsten vorgefundene Schadinsektenart an Weiden im Kurzumtrieb. info:eu-repo/classification/ddc/630 ddc:630
5	Tritrophic interactions between Populus tremula, leaf beetles and their natural enemies - from the field to the laboratory / Tritrophische Interaktionen zwischen Populus tremula, Blattkäfern und ihren natürlichen Feinden - vom Freiland ins Labor von Fragstein und Niemsdorff, Paul-Albin Maximilian 13 September 2011 (has links) No description available. 570 Biowissenschaften Biologie Tritrophische Interaktionen Populus tremula Blattkäfer Chrysomela Phratora Räuber Harmonia axyridis Eumeninae Symmorphus Salicylaldehyd Herbivor induzierte Pflanzen Volatilen Tritrophic interactions Populus tremula leaf beetle Chrysomela Phratora Predators Harmonia axyridis Eumeninae Symmorphus Salicylaldehyde herbivore-induced plant volatiles 42.97 42.75 WN 000: Ökologie {Biologie}

1

Page generated in 0.0503 seconds