Behavioral Ecology Advance Access published online on April 13, 2009
Behavioral Ecology, doi:10.1093/beheco/arp043
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Sexual coercion in Panorpa scorpionflies?—The function of the notal organ reconsidered
Institut für Evolutionsbiologie und Ökologie, Rheinische Friedrich-Wilhelms-Universität Bonn, An der Immenburg 1, 53121 Bonn, Germany
Address correspondence to D. Kock. E-mail: dkKock{at}gmx.de.
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Abstract |
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Conflict between the sexes over the occurrence and timing of copulation is a common feature of sexual reproduction. In Panorpa scorpionflies (Mecoptera, Panorpidae), sexual conflict occurs over mating duration, and it has been suggested that the notal organ—a clamp-like structure on the males’ abdomen—is an adaptation to coerce mating duration, enabling males to prolong mating against female interests. However, as recent studies suggest that female scorpionflies have considerable control over mating decisions, we question this hypothesis and reexamined the function of the notal organ with respect to prolonged mating. We manipulated the notal organs of male Panorpa vulgaris and compared copulation durations achieved by males with functional and nonfunctional notal organs. There were no effects on the overall copulation duration or the period of time a copulation continues after the last nuptial gift has been delivered. We therefore reject the hypothesis that the notal organ is a male adaptation to extend copulation duration against female interests.
Key words: copulation duration, Panorpa vulgaris, prolonged mating, sexual conflict, sexual selection.
Received 29 February 2008; revised 4 November 2008; accepted 18 November 2008.