Might tiger beetles serve as effective predators of fire ants? Preliminary investigations using the golden-spotted tiger beetle, Cosmodela aurulenta (Fabricius)

The red imported fire ant, Solenopsis invicta Buren is listed as one of the most invasive alien insect pests and the fifth costliest worldwide. Sustainable and long-term management of S. invicta is achievable using natural enemy insects. So far, parasitic Pseudacteon flies (Diptera: Phoridae) are the most studied natural enemies of S. invicta, but their low parasitism rate make eradication of S. invicta very difficult. Natural predators of S. invicta are scarcely reported. In this study, we evaluated the control potential of a natural predator, the golden-spotted tiger beetle, Cosmodela aurulenta (Fabricius) against S. invicta. The theoretical maximum daily predation of C. aurulenta adults to small and large S. invicta workers were 29.1545 and 12.4533, respectively. The predation functional responses of C. aurulenta adults on small and large S. invicta workers fit the Holling's type II predator-prey equation. Intraspecific competition and mutual interference among C. aurulenta adults preying on small and large S. invicta workers were detected. C. aurulenta adults showed obvious preference for small S. invicta workers and rapid self-defense reaction on S. invicta worker attack. When fed on Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae) larvae, C. aurulenta adults had significantly higher survival rate and reproductive performance than when fed on S. invicta. Our study exploited a natural predator, C. aurulenta, for management of S. invicta and laid a foundation for the mass production of the predator.