Sexual selection mediated by the thermoregulatory effects of male colour pattern in the ambush bug Phymata americana.
Sexual dimorphism in coloration is a taxonomically widespread phenomenon often attributed to sexual selection on visual signals. However, the ambush bug Phymata americana exhibits sexual dimorphism in coloration that has no apparent signalling function. Here we provide evidence that colour pattern in this species influences male mating success indirectly through its effect on thermoregulation. We demonstrate, using experimental manipulation, that individuals with dark colour pattern achieve higher thoracic temperatures under illumination. We also show that dark colour pattern predicted mate-searching success but only under thermally challenging conditions (i.e. cool ambient temperature). As far as we are aware, this is the first study to provide evidence that sexual dimorphism can be accounted for by sexual selection on thermoregulatory performance.
Punzalan
David
D
Department of Ecology and Evolution, University of Toronto, Toronto, Ontario, Canada. dpunzala@uottawa.ca
Rodd
F Helen
FH
Rowe
Locke
L
D000818:Animals; D001831:Body Temperature; D001833:Body Temperature Regulation / Q000502:physiology*; D020062:Heteroptera / Q000502:physiology*; D016014:Linear Models; D008297:Male; D052586:Mating Preference, Animal / Q000502:physiology*; D009864:Ontario; D010858:Pigmentation / Q000502:physiology*; D012641:Selection, Genetic; D012727:Sex Characteristics