After 10 days to two weeks, the larvae are around half an inch long. I have watched bees carry these larvae out of the hive – the bees seem to struggle to kill the larvae.
Hive beetles are opportunistic pests. If you allow them to get into brood and pollen that is not in a hive, they will multiply in this and then return to harass hives.
The beetles carry certain bacteria and yeast, specifically Kodamaea ohmeri. These microbes infect the honey and nectar in the hive and turn this into a sour horrible smelling froth.