Behaviour 2019
Why does the flag-legged bug mysteriously wave its brightly-colored legs?
Cameron Longbottom1,2, Ginny Greenway3, Jay Falk4,2, Meredith Johnson5,2, Ummat Somjee2. 1University of Manchester, Manchester, , United Kingdom; 2Smithsonian Tropical Research Institute, Panama, , Panama; 3University of Florida, Gainesville, , United States; 4Cornell University, Ithaca, , United States; 5Arizona State University, Tempe, , United States

Exaggerated traits and conspicuous behaviour can act as social signals directed towards individuals of the same species or these signals may function primarily across-species. The flag-legged bug, Anisoscelis alipes (Hemiptera:Coreidae), has large brightly-coloured tibial expansions of their hind legs which they use to perform a stereotypic ‘waving’ behaviour. I examine this morphology and behaviour and discuss my findings in the context three major hypotheses: sexual selection, non-sexual social selection and predatory lures or deterrents. I find no direct evidence that these exaggerated traits function as social or sexual signals; both males and females bear them. In experimentally-constructed social groups we documented 318 bouts of leg waving behaviour with 745 instances of leg-waves; we found no difference in the number or rate of leg-waving depending on an individuals’ social environment or sex. In contrast to a social signal hypothesis, individuals were more likely to perform leg-waving if they were further away from each other. We found no evidence that these traits function as social signals and suggest further studies examining across-species signalling hypotheses.