Study: Pesticides in Nursery Plants Killing Bees

Jun 25, 2014

A honeybee comes in for a landing on the same flower occupied by a bumblebee.
Credit Martin LaBar

Bee-lovers who ply nurseries for welcoming plants may be bringing home more than just beautiful blossoms: A new study finds that as many as half of garden plants sold at top retailers contain neonicotinoid pesticides. "Neonics," as they're referred to, have been linked to recent declines in the honey bee population. 

Now, some environmental and consumer groups want big retailers to stop supplying neonic-treated plants or require warning labels.  But some gardening and bee experts say the evidence against using neonics is murky.

The report, called "Gardeners Beware," was spearheaded by Friends of the Earth US and the Pesticide Research Institute, and supported by other environmental and consumer organizations. The groups tested for pesticides in 71 plants purchased from large garden retailers across 18 cities, including Portland, says Charlotte Warren, spokesperson for the national Organic Consumers Association.

"The testing revealed that many home garden plants sold at Home Depot, Lowe's and Wal-Mart stores in the Portland area, have been pre-treated with pesticides shown to harm and kill bees," she said today at a press conference.

Master Maine Beekeeper Erin MacGregor-Forbes says plants treated with neonics retain the pesticide for their entire lives. "Neonicotinoids insecticides are systemic insecticides which are treated on the plant, absorbed into the plant, and then expressed through the pollen and nectar and the leaves of the plant," she said.

And many people who buy these plants, says Forbes, think they are bee friendly, when they may actually harm or kill them.  

There's been worldwide concern over bee populations, which have declined by about a third since 2006, in a phenomenon called Colony Collapse Disorder. Though the decline has been attributed to a host of factors, Charlotte Warren says the report is part of a growing body of evidence that neonics play a major role.

Some big retailers are taking notice. BJ's Wholesale Club announced Wednesday they will require vendors to either stop supplying neonic-treated plants, or require warning labels. 

Charlotte Warren says other retailers should follow BJ's lead. "We're here today to ask Home Depot, Lowe's and WalMart to do the same," she said.

"We don't want to hurt the environment - we hate spraying," says Tom Estabrook, vice president of Estabrooks Farm and Greenhouses in Yarmouth. He says there are conflicting studies on how much neonicotinoids harm bees. As the debate plays out, he says he'll follow state guidelines, which allow their use.

"Unfortunately, it's a part of our crop," he says. "We have to protect the investment that we've made. We have to make sure the plants are healthy for when they go home with you as a customer."

Estabrook isn't the only one who questions why neonicotinoids are so vilified. Maine State Apiarist Tony Jadzcak says neonicotinoids were developed to replace previous insecticides that were much more toxic.

"I mean, if we're going look at insecticides, maybe we out to look at all of them," Jadzcak says. "Because I think this class of insecticide is kind of taking a bad name, or getting too much bad publicity, compared to some of the other stuff that is commonly used."

Jadzcak says some neonicotinoids on their own are not that toxic.  But they become significantly more so when mixed with certain fungicides. While Jadzcak supports better labeling for neonic-treated plants, he says asking big box retailers to end the pesticide's use could have unfortunate consequences.

"What materials will be put on those shelves in place of that?" he asks. "And my feeling on this is they're going to put some of the older chemistry materials back on the shelves, which we're currently trying to phase out for a variety of reasons."

Others point out that the focus on pesticides is too narrow, when bee population declines are due to a number of factors, including mites, viruses, habitat loss, and poor nutrition.

Master BeeKeeper Erin MacGregor-Forbes acknowledges the issue is complex. "But the neonicotinoids are the one that human beings can control," she says. "The problem is, the neonicotinoids are the one component actually earn somebody money, and that is the reason it's so difficult to fight."

One garden center says stopping their use may not be as difficult as it seems.  Highland Avenue Greenhouse in Scarborough says they "grow naked" - meaning no pesticides. Co-owner Christine Viscone says it happened by accident - the greenhouse lost its pesiticide license when out-of-state credits didn't transfer to Maine.

"We decided, you know what? Instead of going back and taking the test again, we're going to implement what we've been learning for years in all of these pesticide credit seminars," she says. "They're teaching us about how to use biologicals."

Viscone says the change was surprisingly doable and it's in line with demand from eco-conscious customers.  To what extent other greenhouses may need to change their pesticide policies will be decided in the near future.  President Obama has asked the Environmental Protection Agency to assess the effect of pesticides like neonicotinoids on bees and other pollinators within the next six months.