A case of omnivory: an iolinid predatory mite can feed on a fungus, the plant and a pest on tomatoes

• Ano de defesa: 2024
• Autor(a) principal: Assis, Caio Henrique Binda de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Pragas agrícolas - Controle biológico; Ácaros no controle biológico de pragas; Tomate - Doenças e pragas - Controle biológico; Oidium; Entomologia Agrícola
• Link de acesso: https://locus.ufv.br/handle/123456789/33776; https://doi.org/10.47328/ufvbbt.2024.433

The specificity of natural enemies is a central topic in biological control, and the use of specialists or generalists has been extensively discussed since the formal adoption of biological control as a pest management technique in 1889. For a long time, specialist natural enemies were considered superior to generalists and were therefore more widely employed. However, over the last few decades, successful biological control has been achieved through the use of generalist predators in various cultivation systems, making them widely adopted in biological management programs. Generalists can feed on various food sources, enabling them to establish and persist in crops even during periods of prey scarcity, while also allowing for preventive control measures. Some of them can also simultaneously control multiple pests and reduce the costs and complexity of biological control. Predatory mites are among the most important natural enemies employed in the control of crop pests. Several of them are omnivorous, they do not feed only on other arthropods, but also on fungi, pollen, and plant tissue. For instance, many predatory mites have been shown feeding on fungi and even control plant diseases. Some of them can also feed on plant tissue and affect pests directly by attacking them, and indirectly by eliciting plant defences. In this work, I explored the potential of an iolinid predatory mite cf. Homeopronematus anconai sp. nov. for the biological control of pests in tomato plants. This predator has been shown to control powdery mildew infections caused by Oidium neolycopersici in tomatoes and potentially trigger defence responses in these plants. Hence, the main objective of this study was to assess the mechanism used by the predator to control powdery mildew. In the first chapter, I assess whether it controls this disease by feeding on the fungus, and in the second chapter I evaluate whether the plant feeding by this iolinid mite triggers defence responses in tomato plants, which could subsequently reduce powdery mildew growth. I demonstrate that the iolinid indeed feeds on powdery mildew and can reproduce by feeding on it. I found no evidence of the iolinids inducing plant defences. Keywords: Omnivory; Biological control; Disease management.