Data from: X-ray micro-CT scanning reveals temporal separation of male harm and female kicking during traumatic mating in seed beetles

Dougherty_Simmons_all_data.xlsx (10.40 Kb):
Data on degree of copulatory wounding for all pairs scanned.

Video S1.mpg (86.60 Mb):
3D volume rendering showing a male aedeagus partly everted inside a female during the early stages of mating (pair frozen in copula after 60 seconds of mating, female not shown). The colour represents the relative X-Ray attenuation (brightness) of the tissue, with red representing highest density and blue representing lowest density.

Video S2.mpg (47.67 Mb):
3D volume rendering showing a fully everted male aedeagus inside a female during the early stages of mating (pair frozen in copula after 60 seconds of mating, female not shown). The colour represents the relative X-Ray attenuation (brightness) of the tissue, with red representing highest density and blue representing lowest density.

Video S3.mpg (72.61 Mb):
3D volume rendering showing the interaction between the male aedeagus (colour) and female copulatory tract (greyscale) during the early stages of mating (pair frozen in copula after 60 seconds of mating), viewed from the side. The colours represent the relative X-Ray attenuation (brightness) of the tissue, with red/white representing highest density and blue/dark grey representing lowest density for male and female traits respectively.

In the seed beetle Callosobruchus maculatus, the male intromittent organ is covered in sharp spines that pierce the female copulatory tract wall during mating. Although the fitness consequences of traumatic mating are well studied in this species, we know much less about how the male and female genitalia interact during mating. This is partly due to the fact that genital interactions occur primarily inside the female, and so are difficult to observe. In this study, we use X-ray micro-CT scanning to examine the proximate mechanisms of traumatic mating in C. maculatus in unprecedented detail. We show that this technique can be used to identify female tissue damage before the melanization of wound sites. We visualize the positioning of the male intromittent organ inside the female copulatory tract during mating, and show how this relates to tract wounding in three dimensions. By scanning pairs flash-frozen at different times during mating, we show that significant tract wounding occurs before the onset of female kicking. There is thus some degree of temporal separation between the onset of wounding and the onset of kicking, which supports recent suggestions that kicking is not an effective female counter-adaptation to reduce copulatory wounding in this species. We also present evidence that the sharp teeth protruding from the female tract wall are able to pierce the spermatophore as it is deposited, and may thus function to aid sperm release.