Data from: Males evolve to be more harmful under increased sexual conflict intensity in a seed beetle

One conspicuous manifestation of sexual conflict is traumatic mating, in
which male genitalia damage the female during copulation. The penis of the
seed beetle, Callosobruchus maculatus, is covered in spines that damage
the female reproductive tract. Females kick males ostensibly to shorten
these harmful copulations. How these iconic conflict behaviours coevolve
in response to sexual conflict intensity can provide insight into the
economics of these traits. We examined whether male harm and female
resistance coevolved in response to elevated sexual conflict. We
quantified copulation behaviour and female reproductive tract damage of
individuals from replicated populations evolving for 32 generations under
low or high sexual conflict (female- and male-biased treatments,
respectively). First, we permitted females ad libitum matings with males
from either sex-ratio treatment, recording her tract damage and longevity.
Second, we performed a full-factorial cross of matings by males and
females from each of the replicate populations, recording mating and
kicking duration and reproductive output. We found manipulation of sexual
conflict intensity led to the evolution of male harmfulness, but not
female resistance to harm. We also demonstrate that female kicking does
not respond to sexual conflict intensity, suggesting it does not function
to mitigate male harm in this species. Our findings demonstrate the
complexities of behavioural and morphological co-evolutionary responses to
sexual conflict intensity in an important model species.