Varroa mite
I hate these soooo much . . .
This is one that, as a hobbyist beekeeper, I am all too familiar with:
This is a varroa mite, Varroa destructor[1]. They are a parasite of honey bees, derived from a parasite of the asiatic honey bee Apis cerana. The asiatic honey bee has established a stable host/parasite relationship with their strain of varroa mites, so the mites don’t wipe out their colonies. Unfortunately, the western honey bee Apis mellifera, the one that most of modern beekeeping is based on, has not established such a relationship, and if left alone these mites will wipe out a normal western honey bee colony within 1-3 years, depending on the climate. These mites got into North America (probably on imported bees, but nobody is quite sure when or where), in the early 1980s, and have come close to wiping out both commercial and hobbyist beekeeping in the US several times since then.