Male Armaments and Reproductive Behavior in "Nutcracker" Camel Crickets (Rhaphidophoridae, Pristoceuthophilus)

Males of many species possess striking weaponry used in intrasexual competition for access to females. Until recently, there were no known cases of male weaponry being used against females in sexual coercion. However, in the camel cricket, Pristoceuthophilus marmoratus, males use modified hind legs to fight with each other and also to trap females and force them to copulate. To determine whether hind leg armaments serve similar fighting and mating functions in morphologically similar congeners, we performed a comparative survey of armament use in intra- and inter-sexual interactions in four additional species of Pristoceuthophilus (P. arizonae and three undescribed species: P. 'Huachuca summer,' P. 'Madera' and P. 'Mt. Pinos'). Intrasexual leg fighting occurred in all species for which trials were performed, and hints of sexual coercion occurred in two species (P. 'Huachuca summer' and P. 'Mt. Pinos'), suggesting additional cases of a uniquely dual-purpose armament. These findings suggest an evolutionary exaptation of hind leg armaments in this genus, wherein an intrasexual fighting weapon took on a secondary function of sexual coercion.