  The large-$N_c$ orientifold planar equivalence between $\mathcal{N}=1$ SUSY
Yang-Mills theory and ordinary 1-flavor QCD suggests that low-energy
quark-gluon dynamics in QCD should be constrained by the supersymmetry of the
parent theory. One SUSY relic expected from orientifold equivalence is the
approximate degeneracy of the scalar and pseudoscalar mesons in 1-flavor QCD.
Here we study the role of the $q\bar{q}$ annihilation (hairpin) contributions
to the meson correlators. These annihilation terms induce mass shifts of
opposite sign in the scalar and pseudoscalar channels, making degeneracy
plausible. Calculations of valence and hairpin correlators in quenched lattice
QCD are consistent with approximate degeneracy, although the errors on the
scalar hairpin are large. We also study the role of $q\bar{q}$ annihilation in
the 1- and 2-flavor Nambu-Jona Lasinio model, where annihilation terms arise
from the chiral field determinant representing the axial U(1) anomaly.
Scalar-pseudoscalar degeneracy for the 1-flavor case reduces to a constraint on
the relative size of the anomalous and non-anomalous 4-fermion couplings.
