In a spring ritual as old as life itself, Steve Ellis’ bees return to their hives day after day loaded with pollen from the dandelions and flowering trees that are in full bloom across central Minnesota.

But for too many of them, a day of foraging ends in convulsions and death.

“You wouldn’t think people could get attached to insects,” said Ellis, a commercial honey producer from Barrett, Minn. “But it’s hard for us to see our bees getting injured like that.”

Hard enough that Ellis and other beekeepers from Minnesota and across the country this month asked the federal government for a temporary ban on one the most widely used pesticides until its effect on bees is clear. They fear it is contributing to a worldwide die-off and the inexplicable phenomenon known as “colony collapse disorder” that is devastating honeybee hives.

“We are asking the EPA to do its job,” said Jeff Anderson, a commercial beekeeper from Eagle Bend, Minn. “Give us products that are safe.”