Copulation and Spermatophores in the Ephippigerinae (Orthoptera: Tettigoniidae): Prolonged Copulation Is Associated with a Smaller Nuptial Gift in Uromenus rugosicollis Serville

In the majority of bushcrickets, copulation ends within minutes after the transfer of a spermatophore which consists of two parts: a sperm-containing ampulla and a spermatophylax which the female eats during sperm transfer. Recently, the function of the spermatophylax in bushcrickets has been the subject of considerable debate. Here, I describe prolonged copulation following spermatophore transfer which appears to have partly replaced the spermatophylax in function in the bushcricket Uromenus rugosicollis (Ephippigerinae). I contrast this with the copulatory behavior of 15 other members of the Ephippigerinae. In U. rugosicollis, copulation following spermatophore transfer is long, lasting about 100 minutes, and the spermatophylax is small, representing about 7% of male body weight. This stands in contrast to the 15 other species of ephippigerine, in which copulation following spermatophore transfer is typically brief, lasting an average of about 5 minutes, and the spermatophylax is large, representing over 20 % of male body weight. The association of prolonged copulation following spermatophore transfer with the considerable reduction in spermatophylax size in U. rugosicollis suggests that the spermatophylax and prolonged copulation following spermatophore transfer are analogous in function. This supports the hypothesis that the spermatophylax functions to prevent the female from eating the ampulla before complete sperm transfer, but does not