Small Predator, Big Opportunities: A case study examining dynamics of predator Franklinothrips megalops and prey Scirtothrips aurantii in avocado orchards in eastern Spain

Avocado (Persea americana) production has expanded rapidly across Mediterranean Spain, increasing the vulnerability of these perennial agroecosystems to invasive phytophagous species such as Scirtothrips aurantii. Despite the economic importance of this pest, ecological understanding of its interactions with the natural enemy Franklinothrips megalops remains limited under commercial, multi-cultivar production conditions. This study examined the population dynamics of both species in an experimental avocado orchard in Villarreal, Spain, during the 2025 growing season. Stratified beat sampling and generalized linear mixed models (GLMMs) quantified the effects of abiotic drivers, host plant cultivar, and predator–prey lag structure on arthropod abundance. Results show that temperature primarily drives S. aurantii dynamics, with a strong positive relationship consistently associated with late-summer population peaks across cultivars. In contrast, F. megalops exhibited a significant 14-day lagged numerical response to prey abundance, indicating a temporally delayed predator–prey interaction. Although the predator persisted across multiple generations within the orchard, its delayed response suggests it functions more as a background regulator than as an immediate suppressor of rapidly developing pest outbreaks. These findings indicate that F. megalops, while an important component of orchard biodiversity, is unlikely to provide rapid control of temperature-driven pest surges. Consequently, effective integrated pest management (IPM) should prioritize monitoring during late-summer periods and emphasize conservation of resident natural enemies through selective, non-disruptive interventions. In Mediterranean climates facing similar invasive pressures, these results provide a transferable framework for improving sustainable pest management in avocado production.