With most managed US hives used to pollinate California’s almond crops, it’s alarming to learn that a common almond fungicide threatens honey bees. New research published in the Journal of Economic Entomology on Tuesday of this week reports findings that the fungicide iprodione greatly reduces foraging honey bee survival rate. Not in excessive amounts, but in doses commonly used by almond growers.
The study done by the apiculture lab in the Department of Entomology at Texas A&M University included testing repeated three times in the fall of 2015. The team working on the project included USDA Agricultural Research Service scientists, doctoral researchers, and the assistant professor of apiculture, Dr. Julia Rangel.
“”Given that these fungicides may be applied when honey bees are present in almond orchards, our findings suggest that bees may face significant danger from chemical applications, even when responsibly applied,” says Juliana Rangel, Ph.D.” — Eureka Alert
Apiculture scientists from the Rangel Honey Bee Lab at Texas A&M made an observatory trip to the almond orchards in 2012. What they saw there during pollination led to these tests run late in 2015. No doubt the process of researching all related previous studies is a time-consuming task. Especially with over 50 pesticides in use in California’s almond orchards during bloom. The initial discovery phase wasn’t fast or easy, but necessary to weigh all existing knowledge against this new situation.
Are there really FIFTY different pesticides on the trees those honey bees are foraging? That’s what the journal paper says, so it can’t be bad information. And that’s just during the week or two the trees are flowering. There are likely more pesticides
They placed groups of foraging honey bees in wind tunnel exposure experiments using varying combinations of the most suspect chemicals. Of course, the control group enjoyed a wind tunnel with no pesticides at all. Monitoring in separate habitats followed exposure for 10 days. Bees exposed to a recommended rate application of iprodione died 2-3 times faster than the unexposed control group. And the death toll escalated when the iprodione was mixed with other pesticides.
Surprisingly, well, perhaps not, because bees are bugs. Lowly creatures on the human totem pole. Anyway… multiple times from beginning to end of the published paper, lead author Adrian Fisher II states that little to no toxicological study has been done on whether or not fungicide threatens honey bees. Curious, don’t you think when so many crops depend on them to create a harvest?
The toxicological components section of the Material Safety Data Sheet for Iprodione 2SE Select shows only tested toxicity levels in rabbits and rats. Neither of which would climb a fruit or nut tree in search of a meal of flowers. I know, they’re standard lab test animals, but the protocol makes little sense in this instance. What about harm to beneficial creatures, like bees and butterflies? And what affect does it have on butterflies? Because Monarchs traffic blooming almond trees too.
Furthermore, the iprodione fungicide threatens honey bees long after application. And not just the foraging bees, but the colony. The foragers’ deposit pollen tainted with the fungicide in the hive where it hangs around into the future. Remember the measurements of residual pesticides in honeycomb several years ago? In some hives they found over 20 individual chemicals present. And then there’s the added exposure of grooming where bees, like many creatures, ingest what’s on their body in the process of cleaning themselves.
The fastest, easiest, most effective way to put a stop to situations like this where fungicide threatens honey bees – is to stop pollinating almonds with them. Or putting the majority of the country’s bees in peril simultaneously. Not that the beekeeping industry would like that idea. Almond pollination is big money made fast. But conventional farmers aren’t about to stop using pesticides. It would take years, perhaps decades, to test every pesticide in use on crops that managed honey bees service to discover if it poses a threat to them or not. Then they have to figure out how to reduce or eradicate its harm to pollinators.
The planet doesn’t have the luxury of waiting for this to happen. If the bees continue dying at current rates, they will be extinct by 2035. The thing is, the world could have almonds without honey bee pollination.
Like many crops, there are self-pollinating almonds too. It’s the type of trees being grown that requires so many bees to ensure an ample harvest. Reports of science working on developing such an almond variety surfaced back in 2010, even though one has existed for centuries. So, why aren’t almond farmers growing that tree instead of paying so much for guaranteed pollination? Bigger nuts. A nut that’s larger than other possibilities equals more pounds per acre, more money per pound, and then there are the consumers who prefer the biggest fruit in the pile. Bigger is king. Supersize it.
Ah, but you see, a modern, patented almond already existed in 2008, known as Independence. How curious the USDA reportedly started trying to develop one 2 years later! The world almond supply is a pretty big pie, and California grows several different kinds of almonds. Almond farmers usually grow at least 2 varieties. And there are early, mid, and late ripening types. Staggered harvesting makes huge almond farms more feasible.
The Independence Almond produces nuts the size of the preferred Nonpareil, and around the same time. They are both mid-season harvests with similar per acre yield weights. But it takes years for a fruit tree to prove it’s productivity potential. Trees planted in a commercial orchard during the patent year would just now be entering mature harvest yields after 8 years of growth.
In the future, more growers may switch from Nonpareil to this newer Independence Almond. But only after the production life of existing trees calls for replanting. An almond orchard has a 25-year life span. So, it could be a quarter of a century before all these bees are safer from pesticides. Maybe longer, because to my understanding, the early and late ripening varieties still need heavy pollination.
And what suggestions do the apiculture scientists have for this almond fungicide threatens honey bees dilemma?
“When considering the use of fungicides during the almond bloom, cautious fungicide application in almond orchards is recommended to prevent unplanned forager exposure to these chemicals. Perhaps avoidance of such applications during bloom or applying fungicides during times of low honey bee forager activity, such as late evenings, would help mitigate the direct and potential secondary effects of fungicides to honey bee colony health.”
Crop dusting after dark… Wouldn’t it be wiser to simply enforce tree replacement? After all, honey bees are important to a lot more plants than these almonds. Plants the world, and Nature, can’t live without. Then again, the bees and other pollinators could still be exposed to iprodione, because according to Cornell University:
“Iprodione is a dicarboximide contact fungicide used to control a wide variety of crop diseases. It is used on vegetables, ornamentals, pome and stone fruit, root crops, cotton and sunflowers to control a wide variety of fungal pests. It may also be used as a post harvest fungicide and as a seed treatment.”
- Journal Paper
- Iprodione MSDS
- Self-Pollinating 2010
- Independence Almond orchard
- Independence Almond patent
- Bees extinct 2035
- Cornell iprodione sheet
If you don't find her at the desk - check the gardens. When not writing and weeding, she enjoys a good book, painting junk furniture, and blending the harvest of heirloom tomatoes and chiles into salsas.