Evaluating predatory arthropods for the biological control of the invasive Thrips parvispinus (Thysanoptera: Thripidae) in greenhouse sweet pepper

Abstract BACKGROUND Thrips parvispinus is an invasive pest of increasing concern in European greenhouse crops, especially sweet pepper. Its recent spread in southeastern Spain has disrupted integrated pest management protocols relying on inoculative releases of Orius laevigatus and Amblyseius swirskii . Although these predators effectively control Frankliniella occidentalis , their effectiveness against T. parvispinus is unclear. We evaluated the efficacy of O. laevigatus , A. swirskii , and the thrips‐specific Franklinothrips vespiformis , alone and combined, against T. parvispinus under semi‐field greenhouse conditions, also assessing predator compatibility, pest and predator distribution, and crop productivity. RESULTS O. laevigatus , alone or in the three species combination, provided the most effective pest suppression. F. vespiformis was compatible with O. laevigatus , although A. swirskii abundance declined in the combined treatment, suggesting intraguild interactions between predators. T. parvispinus was primarily a leaf‐dwelling thrips, with only 5.5% of individuals found in flowers. However, this proportion varied depending on predator presence, suggesting predator‐induced movement. Notably, pest abundance in flowers was higher in the A. swirskii treatment compared with the other predators and the control, suggesting predator‐induced behavioral avoidance. Fruit productivity mirrored overall pest suppression, with significantly higher yields observed in the O. laevigatus and combined treatments. CONCLUSION These findings refine our understanding of predator interactions and support the inclusion of compatible thrips‐specific predators as promising components of biological control strategies for T. parvispinus in sweet pepper crops. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.