Non-consumptive effects mediated by fire ant footprints mitigate fruit damage by Bactrocera dorsalis (Hendel)

Abstract Bactrocera dorsalis (Hendel) is a major global pest of fruits and vegetables. Interestingly, field studies revealed that the presence of the red imported fire ant, Solenopsis invicta Buren, reduces the visiting frequency of B. dorsalis and fruit damage. However, the underlying mechanisms remain unknown. In this study, we hypothesized that S. invicta can produce semiochemicals that non-consumptively repel B. dorsalis , thereby reducing damage to fruits caused by feeding and oviposition. We investigated how S. invicta poop, saliva, and footprints influence the behavior of B. dorsalis . Subsequently, we analyzed the chemical composition of S. invicta footprints and conducted field experiments to evaluate their efficacy as repellents against B. dorsalis . The results demonstrated that S. invicta footprints effectively repel the visiting behavior and decrease the number of eggs laid by B. dorsalis . Among the nine compounds identified, d-limonene, acetic acid, and a mixture of seven compounds showed strong repellent effects on the visiting frequency and egg-laying of B. dorsalis . Field experiments confirmed the effectiveness of S. invicta footprint compounds in controlling B. dorsalis , resulting in reduced fruit damage in mango, guava, and wax apple trees. These studies provide valuable insights into the non-consumptive effects of S. invicta footprints on B. dorsalis behavior, unraveling the chemical communication between these two invasive species, and offer new pest control methods using invasive predators when direct release is limited.