Aprici

Another two colonies lost.  That makes 4 colonies lost to something fast acting and mysterious.  One week the colonies are strong, the next they are all gone, or almost all gone.  One of the colonies had a few bees left.  No sign of disease, the bees are just gone.  No sign of queen cells either, so they did not attempt to replace their queen or swarm.  Very odd.  The wasps have been very strong recently, killed dozens of them and the traps have caught hundreds, but it is difficult to tell if they are the culprits.

Started treating colonies with an Oxalic acid vapourizer.  This should cause any exposed varroah mites to fall on the sticky boards.  It will be interesting to see if there is any effect.   Treated the four central colonies.