Recently I found this Carrion Beetle with a load of mites on it. At first glance, it would suggest that the beetle is infested with parasites.
But instead, from my investigation into the matter, this is more of a cooperative venture between the beetle and mite.
The Carrion Beetle, which can fly, is fond of dead creatures and is adept at seeking them out. The mites, whom cannot fly, like to eat fly eggs which flies lay on rotting things. The mites taste for fly eggs helps the Carrion Beetle as the less fly maggots eating a carcass means more food for the beetle and its larvae. The mites hitch a ride on the beetle to find a new food source leaving beetle larvae and some juvenile mites behind. When the beetle larvae emerge as a beetle after going into a pupae, the mites that were left behind are ready to jump on. And thus the cycle continues.
Gord Fraser Valley Birding Administrator eBird Regional Editor (Fraser Valley)