Albert Devries told the London (Ontario) Free Press he's been finding scores of dead bees outside his hives at several locations and his commercial honey harvest is going to be lean.
"Each of the yards we've been to show signs of poisoning," he said.
He acknowledged the hot, dry summer that's plaguing the United States and southern Canada could be part of the reason the bees are dying.
The president of the Ontario Beekeepers' Association, John Van Alten, told the newspaper honeybees aren't usually attracted to corn, although that could happen if other pollen and nectar sources were stricken by drought.
The summer die-off follows one in the spring that both Ontario provincial and federal agriculture officials linked to poisoning by an insecticide used by corn farmers at planting time, the report said.
Devries said on average, for every dead bee found near a hive, 10 others likely died in the fields.
He said his various colonies will survive, but their production has been severely cut back by the deaths of so many "forager bees."