IN APRIL, Dena Rash Guzman welcomed six new beehives onto her rural Sandy property. Two months later, at the height of pollinating season, she found a six-inch layer of dead bees in what was once her healthiest hive.
She has yet to find a solid explanation.
"I was shocked," Guzman says. "We live in beautiful open farmland—where the Bull Run meets the Sandy River—away from the farms that spray pesticides. This shouldn't be happening in June."
Usually, she says, mass bee die-offs take place in the winter, because of starvation or freezing—not at the peak of pollen production. Yet Guzman's hive is one of many hit by unexplained die-offs this summer.
According to the Oregon Department of Agriculture (ODA), bees in five independent colonies across Clackamas County died suddenly in the past month—and those are just the reported incidents. They also follow a large June die-off in Eugene, blamed on pesticides, and another headline-grabbing die-off last year in Wilsonville.
While the ODA is still figuring out what caused these Clackamas incidents, bee researchers and farmers are pointing to a familiar culprit: pesticides—especially the kind favored by Oregon's tree nurseries.
After a mass die-off last summer—in which tens of thousands of bees dropped dead because of pesticide ingestion—ODA didn't wait to act. It banned the use of pesticides containing bee-harming neonicotinoid chemicals such as dinotefuran and imidacloprid on lindens, which are the flowering ornamental trees linked directly to past bee deaths. All new pesticide products in Oregon now carry a label with this information.
But it might not be enough.
No one knows how many old unlabeled containers are still in use, and how many farmers are unaware of the new restrictions. Beekeepers hailed Oregon for taking action last year—a measure many states wouldn't consider due to the potential threat to their region's agriculture industry—but a glaring loophole remains in place.
"There is still a lot of the old product out there, if that is the cause of these die-offs," says Bruce Pokarney, an ODA spokesman. "It's not an easy process in an area with so much agriculture. I'm not sure if we'll ever get to all the answers. In general, when you see bee activity on your plants, that's a good time to assess if you should use pesticides at all."
For large-scale agriculture, pesticides can be the deciding factor between a profitable or puny harvest season. According to Pokarney, a recent uptick in aphids on linden trees in Oregon nurseries has likely increased the use of bee-killing pesticides on the trees—be it illegal or not.
For now, there are few replacements for the banned pesticides, and those that do exist will require seasons of testing before going mainstream. Plus, the US Environmental Protection Agency (EPA) only reevaluates pesticides every 15 years—and the next review won't be until 2018. In hopes of expediting the process, Oregon Congressman Earl Blumenauer introduced a bill last year looking to suspend the use of neonicotinoid-based pesticides nationally until the EPA takes a closer look.
According to a recent study by environmental group Friends of the Earth, more than half of pesticide products sold in US garden retail stores contain neonicotinoids.
"These pesticides are ubiquitous," says Aimee Code, pesticide program coordinator for the Xerces Society, a conservation group dedicated to invertebrates. "I do hope that what ODA has done to ban pesticides will stop some of the high-profile die-offs. But in reality, it's a much greater problem than this. We're hooked on pesticides."
Beekeepers increasingly see lush, rural agricultural land as a more dangerous habitat for their hives than the inner city. Bees can fly up to five miles from their hives to pollinate—so the farther away from farmed land, the better.
"It seems backward, but I think bees are safer in an urban setting, away from mass pesticide users," says Matt Reed, Portland beekeeper and owner of beekeeping supplier Bee Thinking.
Which is what beekeeper Guzman has ultimately come to realize.
"The only thing I can do to keep the rest of my bees safe is move them," she says. "If I could put them on leashes, I would. But it's not that easy."