Drosophila suzukii is a pest affecting a wide range of host plants, causing severe damage to small fruits, berries, and grapes. This study analyzed environmental factors influencing its population dynamics in regions where temperature is not a limiting factor. Data were collected in the spring–summer seasons of 2018 and 2019 across three vineyards in northwestern Portugal, examining the relationship between captured D. suzukii females, climatic variables, vine phenological stages, and ecological infrastructures. A stepwise linear model and Pearson correlation matrix were used. In 2020, a winter study was conducted in nine vineyards, focusing on landscape composition and its effect on D. suzukii populations. An ecological infrastructure index was created and correlated with captures data. Results show that vine phenological stages and nearby ecological infrastructures significantly affect population dynamics in spring and summer. Vineyards surrounded by complex landscapes, especially with wild hosts, supported higher D. suzukii populations during winter. These findings highlight the importance of ecological infrastructures in managing D. suzukii populations year-round and suggest their consideration in pest control strategies.

BACKGROUND: Essential oils (EOs) from Eucalyptus globulus Labill. leaves are widely recognized for their biological properties. However, the influence of leaf age on EOs chemical composition and bioactivity remains unclear. This study aimed to characterize the chemical profiles and biopesticidal potential of EOs extracted from juvenile leaves from young trees (YEEO) and adult leaves from mature trees (AEEO) against relevant agricultural pests and pathogens. RESULTS: Metabolomic profiling revealed similar overall compound diversity between YEEO and AEEO. YEEO contained higher levels of α‐pinene and β‐pinene, whereas AEEO was richer in oxygenated compounds, such as 1,8‐cineole and trans‐pinocarveol. Herbicidal activity was tested against Portulaca oleracea and Solanum nigrum in pre‐ and post‐emergent assays, showing strong post‐emergent effects with 100% mortality at the highest concentrations. Both EOs also displayed dose‐dependent antibacterial activity, with Clavibacter michiganensis subsp. michiganensis being the most susceptible, followed by Xanthomonas euvesicatoria and Pseudomonas syringae pv. tomato . No antifungal activity was observed against Alternaria alternata or Botrytis cinerea , but both EOs exhibited potent insecticidal activity against Phthorimaea absoluta larvae, achieving total mortality at the highest concentration (50% v/v) and low LC₅₀ (15.2% v/v for YEEO and 14% v/v for AEEO) and LC₉₀ values (41.4% v/v for YEEO and 38.5% v/v for AEEO). CONCLUSION: Despite their chemical differences, YEEO and AEEO showed comparable herbicidal, antibacterial, and insecticidal effects, highlighting the feasibility of large‐scale EO production, especially by valorizing adult leaves, a by‐product of the paper and furniture industries. These findings highlight the potential of E. globulus EOs as bioactive agents against weeds, insects, and bacteria; however, further field studies are required to evaluate their practical applicability. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.