Foord, S. H.Joubert, E.Manzini, Shaun2025-01-142025-01-142024-09-06Manzini, S. 2021. Compatible components of the integrated pest management of Bathycoelia distincta (Hemiptera: Pentatomidae. Thohoyandou, South Africa.<https://univendspace.univen.ac.za/handle/11602/2789>.https://univendspace.univen.ac.za/handle/11602/2789M.Sc. (Biological Sciences)Department of Biological SciencesTwo-spotted stink bug, Bathycoelia distincta Distant (Hemiptera: Pentatomidae), is a major pest of macadamia. It causes damage by directly feeding on macadamia kernel throughout the season and reducing nut quality by inducing nut abscission, premature nut abortion, necrotic lesions, deformed kernels, discoloration, or translucent blemishes on the kernel. Currently, growers rely on chemical insecticides to control stink bug populations. However, with overreliance and extensive use of chemical insecticides, the B. distincta has developed some resistance to certain active ingredients Furthermore, there is no doubt that agricultural intensification is the primary driver of the loss of biodiversity globally. Therefore, there is a need to develop Integrated Pest Management (IPM) strategies to effectively minimize the damage caused by B. distincta and the loss of biodiversity due to agricultural intensification. The goal of this study was to investigate the role of landscape context, elevation, flying vertebrates, and pesticide application in shaping arboreal arthropod assemblages and macadamia nut quality metrics and evaluate the efficacy of alternative pest control measures to control B. distincta, explicitly focusing on entomopathogenic fungi and egg parasitoids Trissolcus basalis (Wollaston, 1858) (Hymenoptera: Platygastridae). Landscape context and elevation were the principal factors that explained species richness and arthropod size. Species richness and insect size decreased with increasing pesticide application rate; however, it was not significant. Insect damage did not vary in response to pesticide application, but the proportion of sound kernels decreased significantly with increasing pesticide application. All entomopathogenic fungal treatments were effective against B. distincta, with chitinase enzyme leading to a 95% mortality rate. Under field conditions, EPFs and a chemical knock-down spray showed no significant difference between the treatments. All parasitoid treatments significantly affected B. distincta egg mortality, with two pairs reaching a 100% parasitism rate. The processes that increase sound kernel recovery seem to be related to an increase in invertebrate community diversity and arthropod size, and although the mechanisms related to this are not always clear, the results suggest that arthropod diversity could be a good proxy for these processes. On the other hand, the study results showed that EPFs and stink bug egg parasitoids, Trissolcus basalis, may be used as biological control agents against B. distincta. Overall, the thesis emphasizes the importance of reducing pesticide application and using biological control agents, promoting more sustainable agricultural practices, and supporting biodiversity to improve ecosystem service provided by pest natural enemies.1 online resource (ix, 77 leaves): color illustrations, color mapenTwo-spotted stink bugUCTDMacadamiaIntegrate Pest ManagementPesticidesNut quality metrics595.754PentatomidaeHemipteraPests -- ControlPests -- IntegratedPesticidesMacadamia nut industryMacadamia nutDissertationManzini S. Compatible components of the integrated pest management of Bathycoelia distincta (Hemiptera: Pentatomidae. []. , 2024 [cited yyyy month dd]. Available from:Manzini, S. (2024). <i>Compatible components of the integrated pest management of Bathycoelia distincta (Hemiptera: Pentatomidae</i>. (). . Retrieved fromManzini, Shaun. <i>"Compatible components of the integrated pest management of Bathycoelia distincta (Hemiptera: Pentatomidae."</i> ., , 2024.TY - Dissertation AU - Manzini, Shaun AB - Two-spotted stink bug, Bathycoelia distincta Distant (Hemiptera: Pentatomidae), is a major pest of macadamia. It causes damage by directly feeding on macadamia kernel throughout the season and reducing nut quality by inducing nut abscission, premature nut abortion, necrotic lesions, deformed kernels, discoloration, or translucent blemishes on the kernel. Currently, growers rely on chemical insecticides to control stink bug populations. However, with overreliance and extensive use of chemical insecticides, the B. distincta has developed some resistance to certain active ingredients Furthermore, there is no doubt that agricultural intensification is the primary driver of the loss of biodiversity globally. Therefore, there is a need to develop Integrated Pest Management (IPM) strategies to effectively minimize the damage caused by B. distincta and the loss of biodiversity due to agricultural intensification. The goal of this study was to investigate the role of landscape context, elevation, flying vertebrates, and pesticide application in shaping arboreal arthropod assemblages and macadamia nut quality metrics and evaluate the efficacy of alternative pest control measures to control B. distincta, explicitly focusing on entomopathogenic fungi and egg parasitoids Trissolcus basalis (Wollaston, 1858) (Hymenoptera: Platygastridae). Landscape context and elevation were the principal factors that explained species richness and arthropod size. Species richness and insect size decreased with increasing pesticide application rate; however, it was not significant. Insect damage did not vary in response to pesticide application, but the proportion of sound kernels decreased significantly with increasing pesticide application. All entomopathogenic fungal treatments were effective against B. distincta, with chitinase enzyme leading to a 95% mortality rate. Under field conditions, EPFs and a chemical knock-down spray showed no significant difference between the treatments. All parasitoid treatments significantly affected B. distincta egg mortality, with two pairs reaching a 100% parasitism rate. The processes that increase sound kernel recovery seem to be related to an increase in invertebrate community diversity and arthropod size, and although the mechanisms related to this are not always clear, the results suggest that arthropod diversity could be a good proxy for these processes. On the other hand, the study results showed that EPFs and stink bug egg parasitoids, Trissolcus basalis, may be used as biological control agents against B. distincta. Overall, the thesis emphasizes the importance of reducing pesticide application and using biological control agents, promoting more sustainable agricultural practices, and supporting biodiversity to improve ecosystem service provided by pest natural enemies. DA - 2024-09-06 DB - ResearchSpace DP - Univen KW - Two-spotted stink bug KW - Macadamia KW - Integrate Pest Management KW - Pesticides KW - Nut quality metrics LK - https://univendspace.univen.ac.za PY - 2024 T1 - Compatible components of the integrated pest management of Bathycoelia distincta (Hemiptera: Pentatomidae TI - Compatible components of the integrated pest management of Bathycoelia distincta (Hemiptera: Pentatomidae UR - ER -