- Traumatic insemination
Traumatic insemination is the mating practice of a few species of
insects wherein the male pierces the female'sabdomen with his genitals and injects hissperm through the wound into her abdominal cavity. The most widely recorded example is that of "Cimex lectularius ", the bed bug.Carayon, J. 1966 Traumatic insemination and the paragenital system. In Monograph of the Cimicidae (Hemiptera – Heteroptera) (ed. R. L. Usinger), pp. 81-166. College Park, MD: Entomological Society of America.]Evolution
It is believed the practice of traumatic insemination may have evolved as a means for males to circumvent female mating resistance Arnqvist, G. & Rowe, L. 2005 Sexual Conflict. Princeton NJ: Princeton Univ. Press.] . In response to the costs of traumatic insemination, the females of many species have developed various forms of paragenitalia at the site of copulation,Morrow, E. H. & Arnqvist, G. 2003 Costly traumatic insemination and a female counter-adaptation in bed bugs. Proc. R. Soc. Lond. B 270, 2377-2381.] Reinhardt, K., Naylor R. & Siva-Jothy, M. T. 2003 Reducing a cost of traumatic insemination: female bedbugs evolve a unique organ. Proc. R. Soc. Lond. B 270, 2371-2375.] separate from the genital tract. This system reduces the trauma by providing a guide for the male's genitals which leads to the
mesospermalege , from which the sperm migrate to theovaries . The genital tract remains the means by which the female lays fertilized eggs.Repercussions
The practice of traumatic insemination is believed to be advantageous to the reproductive success of the male while at the same time imposing a cost on females which results in reduced lifespan and reproductive output. The successive woundings each require energy to heal, leaving less energy available for other activities. Also, the wounds provide a possible point of infection, further reducing female lifespan.Stutt, A. D. & Siva-Jothy, M. T. 2001 Traumatic insemination and sexual conflict in the bed bug Cimex lectularius. Proc. Nat. Acad. Sci. 98, 5683-5687.]
References
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