I was feeding my hives Monday and stopped to watch the flights.
I knew that one of my swarms, which had built up to two mediums, had been getting robbed. After watching for awhile, and confirming that the hive next to it was visiting, I reduced the entrance.
Later that same day I went back to find that there were about 150 flies on the landing deck trying to get in. Traffic was brisk, but the flies could not get past the guards.
I see a few flies on all the hives but not like this closed one. Is this a common problem? Could the flies be the main robbers?
Smack dab in the middle of the country.
It's the usual, a strong hive doesn't have a problem. Usually they give up after a while. Even if they don't they don't eat much.