  Using the equivariant virtual cycle of the moduli space of stable maps to
[C/Z_r], or equivalently, the vanishing of high-degree Chern classes of a
certain vector bundle over the moduli space of stable maps to BZ_r, we derive
relations in the Chow ring of Mbar_{g,n}(BZ_r,0). These push forward to yield
tautological relations on Mbar_{g,n}.
