Gamasid or Phoretic Mites

Well I found the answer to why there are mites on this beetle. These are deutonymphs (mite nymphs). They do not feed on the beetle. It's a phoresy (an association between two organisms in which one travels on the body of another, without being a parasite) relationship. Beetles in the family Silphidae (this beetle is genus Nicrophorus) feed on and lay their eggs on carcasses of animals, which are not the most common thing. Often, these carcasses have already been found by fly and have maggots (fly larvae) on them. These mites feed on fly eggs and immature larvae, therefore making room for the beetle larvae to lay their eggs and giving the beetle larvae a chance to grow on a carcass without fly competition. I believe these are Gamasid or Phoretic Mites (likely of genus Poecilochirus ) While they make it harder for the beetle to fly/scavenge, they greatly increase the likelihood that the eggs will grow to adults.