People love almonds, especially when they’re pulverized into a nutty dairy alternative. While the total milk market shrank by $1 billion between 2010 and 2015, the market for almond milk surged by 250 percent. But the well-informed hipster knows that, while milking an almond is definitely less ecologically damaging than milking a cow, a glass of the stuff still requires a whole lot of precious water.
This isn’t to say that the health-conscious should eschew almonds, but their consumption is something you should stop and consider. Are you wasting loads of almond protein by letting your half-gallons go bad in the fridge? Are you paying attention to where your nuts are grown, and how they’re farmed?
Now there’s another reason to take a hard look at your almond habit: According to new research in the Journal of Economic Entomology, the fungicides commonly used on almond trees might prove fatal to honey bees.
The idea that bees might be in trouble is not a novel one. The insects (which, along with other pollinators, contributes billions to the economy) are on the decline around the world, suffering as the result of some combination of chemical exposure, climate change, habitat changes, and disease. Researchers are working hard to figure out why bees are in trouble and how we might stop it, but there are still a lot of gaps in our knowledge.
“I noticed most of the studies out there were only 24- or 48-hour tests on mortality, and mostly on insecticides and pesticides,” said study co-author Juliana Rangel, assistant professor of apiculture in the Department of Entomology at Texas A&M University. “But nothing had been done on fungicides, even though they’re widely used to prevent tree damage in almonds.”
Because insecticides attack insects and fungicides are designed to fight off fungi, researchers hadn’t really explored how these chemicals might harm our buzzing farmhands. But the research that did exist suggested that these chemicals showed up in high levels in pollen, and that they might not be good for bees. The almond industry was an obvious place to start looking more closely: California produces about 80 percent of almonds consumed worldwide, according to the Almond Board of California, and California’s trees rely almost exclusively on honey bees (Apis mellifera) for pollination. Around 60 percent of the world’s managed honey bees end up spending time on California almond farms, and almond farms need fungicides to protect trees from fungal blights.
Rangel and her colleagues took several fungicidal compounds—ones widely used in California, according to recent records—and used a special wind-tunnel to inflict them on honey bees. The tunnel mimics the exposure they’d experience on a real farm by spraying them with tiny, aerosolized droplets in precise doses. They did trials mimicking half the dose bees would be exposed to with a single spray, an entire dose, and a double dose—because according to agricultural reports, trees are often sprayed twice-over in a single season.
“It was important to us to assess the mortality over a 10-day period,” Rangel said, unlike previous studies that had only observed the bees for a day or two after exposure, “because we hear a lot of accounts from beekeepers that come back from an almond bloom and then see their bees dying. It’s not something that happens right away, but they suffer greater losses after an almond bloom. So we can’t be sure, but it might be possible to attribute some of those health effects to the almond farms—even if you don’t see an effect the next day.”
The researchers conducted three separate trials in September, October, and November of 2015, and the effects grew more significant as they progressed into autumn. In the second two trials, bees exposed to the recommended concentration of iprodione fungicides died at two to three times the rate of the unexposed bees after 10 days. And these effects were more pronounced as doses got higher, and as other fungicides were added to the mix—as is often the case on a real farm.
There’s more work to be done on the question of bees and fungicides. Researchers aren’t sure why they harm bees or how, and Rangel would like to see longer studies—month-long assessments of bee mortality—conducted in the future.
“It would also be nice to know if there’s an increase in toxicity based on how they interact,” Rangel said. It’s possible that bees poison themselves by licking fungicides off of their fur while grooming, for example. With so little research on the subject, it’s hard to know how best to stop whatever negative effects the chemicals might be causing.
But giving up your almond habit probably isn’t the answer.
“It’s more about trying to work together with almond producers, and they’re quite open. The Almond Board of California funds a lot of research, a lot of health assessments,” Rangel said. One recommendation she and her colleagues are making is that farmers refrain from spraying fungicides during the day, when bees are hard at work.
“It’s so expensive to rent these trucks used to spray the trees that they just do it whenever they can,” Rangel said. “But our research suggests it might be better to save spraying for when bees are inactive.”
These days hobbyists are actually seeing the worst honeybee mortality rates, Rangel said. “The majority of losses are actually from hobbyists who don’t know what they’re doing. Lots of them don’t know to check for mites, which are still the leading cause of honeybee mortality, or they don’t want to spray against them.”
The most recent numbers actually say that winter mortality rates are dropping—”though the problem is that we’re seeing summer mortalities that weren’t seen or reported before,” she said.
“I’m a positive person, and I think with all the negative news that we’ve heard over the past five six years, all this publicity has helped increase funding for people that need to study honeybees and pollinators in general,” she said. Though she added that she wasn’t sure the current administration would continue to support bee research with the same enthusiasm.
All in all, she believes we’re moving in a positive direction. “People are being more cautious, so hopefully the losses will be curtailed,” she said.