University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Lisa Obwegs
(2020):
Monitoring des Populationsaufbaus und der Befallsdynamik von Halyomorpha halys (Hemiptera: Pentatomidae) in einer Apfelanlage und Hecke zur Erarbeitung möglicher Bekämpfungsansätze.
Master / Diploma Thesis - Institut für Pflanzenschutz,
BOKU-Universität für Bodenkultur,
pp 111.
UB BOKU
obvsg
- Abstract:
- Halyomorpha halys is an invasive pest. The polyphagous nature and the high mobility complicate integrated pest management. A population was established by distributing egg clusters/nymphs in a hedge adjacent to an apple orchard. The population dynamics in the hedge was recorded through beating samples and visual controls. In the orchard an additional pheromone trap was used in order to determine the most suitable monitoring method. The apple orchard was divided into four plots. One plot served as a control plot. In the other plots insecticide applications were performed according to different intervention thresholds. Fruit damage surveys were carried out. Depending on the fruit presence and phenology, wild/ornamental plants had different effects on the population dynamics and distribution. In the orchard nymphs were recorded one week after detection in the hedge. Therefore, hedges should be examined to estimate infestation risk. Beating samples successfully detected the reproduction start but were time-consuming and caused early fruit fall. The pheromone trap led to increased damage in the immediate vicinity. These methods are less suitable for farmers, but probably more efficient for extension services. Defining a treatment date based on ≥15 adults/nymphs or ≥10 adults was not successful. Treatments performed after reaching ≥1 adults/nymphs prevented the establishment of a population and severe fruit damage. Nevertheless, fruit damage increased slightly. As insecticides are less effective against adults, it will be necessary to distinguish between nymphs and adults for future threshold interpretation. In untreated plots, fruit damage increased considerably. The highest infestation closest to the hedge indicated the hedge’s influence. Fruit damage in the crown and at eye level did not differ significantly. This contradicted previous observations. Therefore, investigations regarding the factors that may influence the preferred location of H. halys are necessary.
- Beurteilende(r): Koschier Elisabeth Helene