The impact of global change on the intraguild predation among three predatory mites of Tetranychus urticae in citrus orchards

Abstract

The two-spotted spider mite, Tetranychus urticae, is a key pest of clementine mandarin orchards in the Mediterranean basin. Efective biological control, vital for managing T. urticae populations, involves the phytoseiid mites Euseius stipulatus, Neoseiulus californicus, and Phytoseiulus persimilis. The Mediterranean region is highly susceptible to climate change, with predicted increases in average temperatures and reduced rainfall, with potentially negative consequences for agro-ecosystem dynamics. Given the often-overlooked complexity of species interactions in climate change models, this study investigates into the potential impact of climate change, specifcally extreme events like heatwaves, on intraguild interactions among these key predatory mite species. Our fndings reveal that N. californicus is the most robust intraguild predator under forecasted climate change conditions, outperforming the other two. Conversely, E. stipulatus showed reduced performance under future climatic conditions, further afected by intraguild predation from the other two phytoseiids. Notably, P. persimilis fails to maintain its biological parameters in interactions with both intraguild prey under anticipated climatic conditions, suggesting a low tolerance to global warming in the presence of E. stipulatus and N. californicus, the primary predators of T. urticae in our citrus system. These insights are essential for biological control, as they provide crucial data on the biological paràmetres of natural enemies crucial that are critical to efective pest control in the expected global warming scenarios.