Biological control strategies for managing thrips in strawberry cropping systems : a literature review

Sammanfattning

Introduction: Thrips is one of the most common pests in strawberry crops worldwide that cause severe economic damage to flowers and fruits in strawberry crops. With rising temperatures due to climate change, negative impacts from pesticides on ecosystems and biodiversity, and increasing resistance among thrips species such as Frankliniella occidentalis there is an increasing urge to find efficient biological control strategies to control thrips infestations in strawberry crops in Sweden. Therefore, the aim of this thesis is to explore current biological control strategies to control thrips in greenhouse and open-field strawberry cropping systems. Method: A structured literature search was conducted on April 25th, 2025, on Web of Science where 11 articles were extracted for further analysis for biological control method with result on thrips in crop, natural enemies, crop damage and yield that was compared. In addition, information of Swedish strawberry production, pests and biological control methods was collected from advisors via phone calls and one video meeting. Result: The results from this literature review reveals twelve different biocontrol agents in reducing thrips in open-field and greenhouse strawberry cropping systems such as release of predatory mites, the minute pirate bug (Orius spp.), damsel bugs (Nabis americoferus) and entomopathogenic fungi Beauveria bassiana. Several plant species such as Cyanus segetum, Echium vulgare, Chenopodium album, Capsicum annuum L., Lobularia maritima, Urtica urens, Lamium amplexicaule, Convolvulus arvensis, Sonchus oleraceous and Galega officinalis has proven to increase the presence of natural enemies for thrips. Ornamental pepper (Capsicum annuum L.) and sweet alyssum (Lobularia maritima) decreased the presence of thrips when planted adjacent to strawberry crops while ornamental pepper led to a reduction on crop damage. Conclusion: The findings from this literature review highlights some key research areas for development of biocontrol strategies for managing thrips in open-field and protected strawberry cropping systems in Sweden. The review offers a summary of the most updated scientific findings and can be used as a guidance for researchers, farmers and advisors. By combining different biological control strategies, there is potential to increase cost- benefits for farmers while reducing negative impacts on the ecosystem and human health in strawberry cropping systems.