Do beetles die immediately after falling into diatomaceous earth? I would not think so. Are they able to travel further or work their way back into the hive?
I was doing some looking at this, and I found that my comment earlier about DE being safe for adult bees was inaccurate. DE is most effective on soft-bodied insects (provided they aren't slimy like earthworms, who are protected from DE by their thick coat of mucous), but it can and will also kill hard-bodied insects, like beetles and bees. DE's microscopic particles have edges that are extremely rough which can get in between the joints of insects' exoskeletons and cause extreme irritation, and it can also wear away at the exoskeleton's waxy protective cuticle, which leads the insects to die of dehydration. DE is considered safe for use around bees because it's easy to apply it in ways that the bees won't come in contact with, and I'd imagine that bees' hairy bodies also help to protect them from the dust more than a smooth insect. But nonetheless, it can affect adult bees as well as larvae.
So Phillip, I'd say no, beetles wouldn't die immediately from falling into the DE, since they have to die of dehydration. My question would be: do does the DE incapacitate them quickly enough that they can't or won't crawl back into the hive? Perhaps the DE all in their joints makes it too painful or difficult to move well?
