  Eruptive mass loss in massive stars is known to occur, but the mechanism(s)
are not yet well-understood. One proposed physical explanation appeals to
opacity-driven super-Eddington luminosities in stellar envelopes. Here, we
present a 1D model for eruptive mass loss and implement this model in the MESA
stellar evolution code. The model identifies regions in the star where the
energy associated with a locally super-Eddington luminosity exceeds the binding
energy of the overlaying envelope. The material above such regions is ejected
from the star. Stars with masses $10-100~M_\odot$ at solar and SMC
metallicities are evolved through core helium burning, with and without this
new eruptive mass-loss scheme. We find that eruptive mass loss of up to
$\sim10^{-2}~M_\odot \mathrm{yr}^{-1}$ can be driven by this mechanism, and
occurs in a vertical band on the HR diagram between $3.5 \lesssim
\log(T_\mathrm{eff}/\mathrm{K}) \lesssim 4.0$. This predicted eruptive mass
loss prevents stars of initial masses $\gtrsim20~M_\odot$ from evolving to
become red supergiants, with the stars instead ending their lives as blue
supergiants, and therefore offers a possible explanation for the observed lack
of red supergiants in that mass regime.
