What Looks Like Dancing Isn’t About Courtship
Insects rarely perform for the camera, and their behavior often hides deeper purposes. A recent study by STRI researchers Connor Evans-Blake, Juliette Rubin and Ummat Somjee uncovers a surprising truth about a group of colorful flag-legged bugs: their waving is not a courtship display but a sophisticated anti-predator strategy. The finding challenges the long-standing idea that such conspicuous movements evolved primarily through sexual selection.
The Experiments: Mantids, Katydids, and Thousands of Leg Waves
To test whether the leg waves served mating or rivaling purposes, the researchers exposed matador bugs to two very different arthropods: predatory praying mantids and harmless katydids. They logged nearly 3,000 individual leg waves and tracked how behavior changed in the presence of each predator type. The results were striking. On average, waving increased seven-fold when mantids were nearby, while responses to katydids were minimal.
But perhaps even more telling was the predators’ behavior. Mantids did not attack bugs that were actively waving, suggesting the display might influence predator assessment in real time. The study therefore points to waving as an immediate, context-dependent warning rather than a ritualized courtship signal.
Beyond a Single Species: A Closer Look at a Family
To determine whether waving is an isolated quirk or part of a broader evolutionary strategy, the team looked beyond matador bugs. In Panama they observed related flag-legged species in natural settings and scoured online video repositories. The evidence indicates that at least five related species exhibit similar waving, hinting at a shared anti-predator tactic across the plant-feeding group.
Why Leg Waves Might Deter Toxic Predators
All these flag-waving insects feed on passionflower vines, plants known to carry chemical defenses. That ecological detail raises a plausible hypothesis: the movement may advertise their chemical protection, warn off predators, or create confusion that makes targeting difficult. But scientists caution that the exact mechanism remains unclear. Does waving signal toxicity, disrupt a predator’s vision, or simply overwhelm with exaggerated motion?
“We’re left with more questions than answers,” said senior author Ummat Somjee. “But that’s the beauty of studying insects—hundreds of thousands of species remain unstudied, and close examination often reshapes our understanding of evolution.”
Why This Research Matters: Evolution, Biodiversity, and Ecosystems
Research like this transcends quirky observations. Insects comprise the majority of Earth’s biodiversity and underpin many terrestrial ecosystems. Yet a large swath of insect behavior remains undocumented. By deciphering how prey defend themselves, scientists gain insight into how animals evolve, diversify, and adapt to complex ecological webs. The findings remind us that evolution often favors clever, context-dependent strategies over simple “showy” adaptations.
Takeaway: A Dance That Defends, Not Delights
What appears to be a courtship flourish may instead be a life-saving tactic. The matador bug’s flag-like waving exemplifies how evolution crafts signals that are effective against predators while possibly carrying no mating advantage for the animal’s own species. As researchers expand their surveys to more species and environments, the line between display and defense will continue to blur in the most fascinating ways.
