  Event rates for dark matter detectors in neutralino--nucleus scattering are
studied for supergravity unified models, including the constraint arising from
the $b\rightarrow s\gamma$ experiment. The recent experimental measurement of
this decay by the CLEO Collaboration leads to strong constraints on the SUSY
particle spectrum,and also significantly affects the event rates in dark matter
detectors. The analysis given here uses the accurate method for the computation
of the relic density and leads to a dip in the event rate when the neutralino
mass is $\sim M_Z/2$ due to the $Z$-pole, and similar results hold when the
neutralino mass is $\sim m_h/2$ due to the Higgs pole . Implication of these
results for dark matter detectors are discussed.
