The mites are "phoretic," meaning they are only using the beetle as transportation.
Once it arrives at a carcass, the mites will disembark, and go about feeding on the eggs of blow flies,
the beetle's major competition for the corpse. So, the mites actually benefit the beetle.… Eric R. Eaton

The mites often ride atop the wing covers (elytra) of Nicrophorus carrion beetles, which are turned in on each other during flight,
forming a protected passenger compartment for the mites. The mites seem to sense when the beetle is contemplating flight.
They climb atop the elytra and line up facing forward even before the beetle begins its pre-flight fidgets...Jim McClarin

Those on Nicrophorus ride back on the adult and enter the brood cell and reproduce there...Barry O'Connor

yard, Newburyport, MA