I started my first hive last year from a nuc and it did great. Late summer I took off about 80lbs of honey and left them with two deeps full. They survived the winter, the queen was laying and pollen was starting to come in. Tonight I noticed a big pile of dead bees around the hive. Some were still alive and writhing on the ground, most are missing. I had a mentor come over to have a look and he said it is poisoning. I am rural and the corn is going in a little late this year, its been dry and windy. Neonicotinoids? I don't know but it is very disappointing.