These can be killed easily with vaporized oxalic acid in two treatments spaced a week apart (iirc, dad keeps bees not me). This pretty much eliminated any hive

These can be killed easily with vaporized oxalic acid in two treatments spaced a week apart (iirc, dad keeps bees not me). This pretty much eliminated any hive loss for years now, and we’re convinced this is the fix for colony collapse disorder (at least in our area).