  Core-collapse supernovae (CCSNe) are widely accepted to be caused by the
explosive death of massive stars with initial masses $\gtrsim 8$M$_\odot$.
There is, however, a comparatively poor understanding of how properties of the
progenitors -- mass, metallicity, multiplicity, rotation etc. -- manifest in
the resultant CCSN population. Here we present a minimally biased sample of
nearby CCSNe from the ASAS-SN survey whose host galaxies were observed with
integral-field spectroscopy using MUSE at the VLT. This dataset allows us to
analyze the explosion sites of CCSNe within the context of global star
formation properties across the host galaxies. We show that the CCSN explosion
site oxygen abundance distribution is offset to lower values than the overall
HII region abundance distribution within the host galaxies. We further show
that within the subsample of low-metallicity host galaxies, the CCSNe
unbiasedly trace the star-formation with respect to oxygen abundance, while for
the sub-sample of higher-metallicity host galaxies, they preferentially occur
in lower-abundance star-forming regions. We estimate the occurrence of CCSNe as
a function of oxygen abundance per unit star formation, and show that there is
a strong decrease as abundance increases. Such a strong and quantified
metallicity dependence on CCSN production has not been shown before. Finally,
we discuss possible explanations for our result and show that each of these has
strong implications for our understanding of CCSNe and massive star evolution.
