Reducing a cost of traumatic insemination: female bedbugs evolve a unique organ.
The frequent wounding of female bedbugs (Cimex lectularius: Cimicidae) during copulation has been shown to decrease their fitness, but how females have responded to this cost in evolutionary terms is unclear. The evolution of a unique anatomical structure found in female bedbugs, the spermalege, into which the male's intromittent organ passes during traumatic insemination, is a possible counteradaptation to harmful male traits. Several functions have been proposed for this organ, and we test two hypotheses related to its role in sexual conflict. We examine the hypotheses that the spermalege functions to (i) defend against pathogens introduced during traumatic insemination; and (ii) reduce the costs of wound healing during traumatic insemination. Our results support the 'defence against pathogens' hypothesis, suggesting that the evolution of this unique cimicid organ resulted, at least partly, from selection to reduce the costs of mating-associated infection. We found no evidence that the spermalege reduces the costs of wound healing.
Reinhardt
Klaus
K
Department of Animal and Plant Science, The University of Sheffield, Sheffield S10 2TN, UK. k.reinhardt@sheffield.ac.uk
Naylor
Richard
R
Siva-Jothy
Michael T
MT
D000825:Animal Structures / Q000033:anatomy & histology / Q000502:physiology*; D000818:Animals; D001511:Bedbugs / Q000033:anatomy & histology* / Q000276:immunology / Q000502:physiology*; D005260:Female; D005298:Fertility; D008136:Longevity; D012726:Sexual Behavior, Animal / Q000502:physiology*