Mating Behavior and Dual-Purpose Armaments in a Camel Cricket


David A. Gray, Department of Biology, California State University at Northridge, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA.


Sexual selection has often been dichotomized into intersexual and intrasexual components of selection, favoring ornaments and weapons, respectively. Here, we show that a weapon used in male–male combat is sometimes also used in a functionally similar manner for grasping females during mating. The hind legs of adult males of some species of Pristoceuthophilus camel crickets have strongly bent tibia and stout femora with two large conspicuous spines. Here, we show that (1) leg armature is positively allometric, (2) males use these leg modifications when fighting other males, (3) males sometimes use the same leg modifications in the same functional manner for grabbing and holding females for mating, (4) virgin females show more interest in males than do non-virgin females, and (5) males are more likely to use their leg modifications to grab and hold females when paired with non-virgin females than when paired with virgin females. We interpret these results as suggesting that males employ an alternative coercive mating strategy when paired with unreceptive females; alternative explanations are also discussed.