Here is the story,
Had a nuc at a remote site. Several houses nearby, as well as a few other hives. We had no honey flow last fall, and this late winter early spring has been extremely cold and wet. Beekeepers have lost an extreme number of hives.
Checked on this nuc a few weeks ago, and put some syrup on them. They had been taking the syrup in Feb., and I put another pint on top of the nuc. Two weeks ago, I checked on them, and they were extremely vigorous. Then a few days later, peeked in and they seemed lethargic. It was too cold to look into the hive (we had an very cold march), so I let them be.
Today I checked them, and they had died. I assumed they had starved. Looking down in the hive, I didn't see honey. But I did not pull frames out. Shook out the dead bees on the bottom and brought the woodenware home. I do know a sugar brick would have been a much better choice.
While home, I noticed they had stored sugar syrup on three partial frames. Thought it was odd they would starve out with quite a bit of stored sugar syrup.
Is it wrong for me to think they may have been poisoned? If this happens again, is there any way to test the bees?