Journal of Ethology

, Volume 23, Issue 1, pp 35–41 | Cite as

Last-male paternity of Euborellia plebeja, an earwig with elongated genitalia and sperm-removal behavior

  • Yoshitaka KamimuraEmail author


Both sexes of the earwig Euborellia plebeja (Dermaptera: Anisolabididae) mate frequently. The elongated intromittent organs of males are as long as their bodies. Previous studies have revealed that this organ is used to remove rival sperm from the female sperm-storage organ (spermatheca), the length of which is twice that of the female body. The fitness benefit of sperm removal was quantified using two mating experiments with paternity analysis. As expected, given that the sperm-removal organ is shorter than the sperm-storage organ, males gained only about 20% of paternity per single mating with sperm-saturated females. The significance of frequent repeated matings with the same female by males is discussed.


Anisolabididae Earwigs Euborellia plebeja Last male paternity Multiple matings Sperm competition Sperm displacement Sperm storage 



I acknowledge valuable discussions with T. Suzuki, T. Kusano, and F. Hayashi (Tokyo Metropolitan University). I am grateful to T. Suzuki and two anonymous referees for their helpful comments on previous versions of the manuscript. This research was supported by a research fellowship from the Japan Society for the Promotion of Science for Young Scientists (no. 02404).


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Copyright information

© Japan Ethological Society and Springer-Verlag 2004

Authors and Affiliations

  1. 1.Department of BiologyTokyo Metropolitan UniversityTokyoJapan
  2. 2.Laboratory of Evolutionary and Community Ecology, Department of Environmental Systems, Faculty of Geo-Environmental ScienceRissho UniversitySaitama 360-0194Japan

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