Open for comment: EPA considering approval of brand new insecticide
On December 15, 2017, the Environmental Protection Agency announced that it had received a pesticide petition from Bayer CropScience to register a new active ingredient: tetraniliprole. Tetraniliprole is an anthranilic diamide insecticide that causes impaired muscle regulation, paralysis and death in insects. The intended targets are caterpillars, beetles, flies and sucking insects that have been identified as pests. Bayer is seeking approval for its use on a wide range of food crops including fruiting vegetables, citrus, pome fruits and stone fruits. Public comment was solicited at the time; only six comments were submitted.
Now, three years later, EPA is proposing to unconditionally register several tetraniliprole products. Again, the agency is seeking public comments. The deadline is this Sunday, Nov. 22.
So how concerned should we be about this new kind of pesticide? How much of a danger might tetraniliprole pose to bees?
According to EPA documentation, quite a bit it seems. At the individual bee level, tetraniliprole is highly toxic to:
• larval honey bees
• young adult honey bees on an acute contact and oral exposure basis
• adult bumble bees on an acute oral exposure basis
For both honey and bumble bees, oral exposure is more toxic than contact. And individual honey bees appear to be two to three orders of magnitude more sensitive than bumble bees to contact exposure.
At a colony level, however, EPA says the risks to honey bees are considered low. But at both levels, the danger to bees is considered high when the insecticide is applied before or during boom.
This grim report, like all EPA reviews of novel pesticides, is based on toxicity assessments – which only look at death . The EPA review doesn’t consider the range of possible (and significant) sublethal effects a chemical like tetraniliprole could have on bee populations. But as Harry Siviter, a postdoctoral researcher at the University of Texas at Austin, has pointed out: “If a bee dies, it does not contribute to the next generation. If a bee fails to reproduce, it similarly does not contribute to the next generation. On a population scale, there is no difference.”
This report also, like all EPA reviews, makes the questionable assumption that honey bees can be “considered a surrogate for other species of bees”. It’s hard to see how a highly social species of bee living above ground can be used confidently as a proxy for solitary bees living in the ground when it comes to assessing the impact of pesticides. But in this case, the honey bee-based results might actually give us some insight: tetraniliprole is highly toxic on an individual level – which would be terrible for solitary bees.
But the biggest factor that could determine how harmful tetraniliprole is to bees is how it’s ultimately used in the real world.
Nathan Donley, a senior scientist at the Center for Biological Diversity who helped craft one of the six comments back in 2018, says, all things being equal, he might prefer to see diamides replace neonic insecticides. But he’s not convinced that’s going to happen.
“There is no evidence that new pesticides that EPA keeps approving are actually replacing older chemicals,” he says. Instead, new pesticides are being used in combination with older pesticides: diamides, for example, are being used on top of neonicotinoids and pyrethroids. “So I don’t see any benefit whatsoever to new insecticides or new modes of action. If EPA were to make approvals of new pesticides like tetraniliprole contingent on reduction in neonic use, then we might actually get somewhere.”
Very few independent researchers have had a chance to study this particular diamide, says Donley. The three researchers that I contacted for this story (all of whom have experience in pesticides and bees) said they were unfamiliar with details about this insecticide. The only independently published research I found while writing this story was on a sibling diamide, chlorantraniliprole. (And assuming the impact of one diamide is the same as another seems ill advised: according to EPA’s own toxicity assessment, tetraniliprole looks way more like a neonic than it does chlorantraniliprole.) So the true risks that tetraniliprole poses to bees might not be known for years.
Unfortunately, this is the kind of thing that EPA has become known for: approving pesticides without a robust and comprehensive understanding about their effects on all sorts of life. So if you plan to comment on the possible approval of tetraniliprole by this Sunday, yes, list all of things we do know about its impact on bees and other non-target invertebrates. But please also point out that a big reason to not approve tetraniliprole right now is because there’s a lot of things we don’t know.
Conservation
Rusty patched decline unlikely to have been driven by loss of food resources
(Twitter, Leif Richardson @leifr7) “Has the rusty-patched #bumblebee declined due to loss of food resources? Not according to this analysis of pollen loads from museum specimens.” The original paper.
Non-native leafcutter bees found in Chicago
(Spartan Newsroom) Thirty of the non-native leafcutter bees were found in a heavily urbanized part of Chicago. How they got to Chicago is uncertain, however. Their presence was previously confirmed in Michigan, Ohio and Pennsylvania. “Although we do not know the extent of the impact of nonnative bee species, there is evidence they may compete strongly with native bees for nesting resources."
Pesticides commonly used as flea treatments for pets are contaminating English rivers
(ScienceDaily, University of Sussex) Researchers have found widespread contamination of English rivers with two neurotoxic pesticides commonly used in veterinary flea products: fipronil and the neonicotinoid imidacloprid. The concentrations found often far exceeded accepted safe limits.
Policy/Law
California county seeks public input on how to deal with honey bees
(KCRA) Honey bees are essential to California’s agricultural industry. However, where to house those bees when they are not working is creating an issue in Placer County. "The county currently has no specific guidelines, it’s real arbitrary."
(ABC News) Noosa Shire Council has backflipped on banning new beehives in the suburbs in response to an outpouring of opposition from beekeepers and the public.
Trump rushes environmental rules that could handcuff Biden
(Bloomberg Green) The Trump administration is rushing to issue permits, finalize major environmental regulations and even sell the rights to drill for oil in Alaskan wilderness before Inauguration Day in a push that could complicate Joe Biden’s climate and conservation agenda. This includes reviewing a rule defining the “critical habitat” that gets protection under the Endangered Species Act.
Science
Solitary bees born with functional internal clock – unlike honeybees
(EurekAlert, Frontiers) A common trait of many social insects like honey bees is age-specific behavior: when they emerge from the pupa, workers typically specialize in around-the-clock tasks inside the darkness of the nest, starting with brood care. But they gradually shift towards more cyclic tasks away from center of the nest as they get older. Researchers how found evidence that this shift from around-the-clock to rhythmic tasks, which does not occur in solitary insects, seems to be driven by a slower maturation of the internal "circadian" clock of social honey bees compared to solitary bees. They also found that in solitary red mason bees, Osmia bicornis, females and males emerge with a mature, fully functional circadian clock.
(Twitter, Michael Branstetter @bramic21) “... @thecriticalbee has published an amazing paper on the phylogenomics and biogeography of the parasitic bee group Neolarrini...” The original paper.
Society/Culture
Research finds that Canadians need to “bee” more curious
(Excalibur) Researchers at York recently found that the majority of Canadians lack significant knowledge about bees. Native pollinators in Canada are essential to sustain the many species that rely on them, and the ecosystem as a whole. Experts say that increasing and improving the Canadian public’s knowledge of bees is a key step in increasing their legal protection and supporting conservation efforts.
The distinctive black beehives of Turkey’s ‘Honey Forest’
(New York Times) The beekeeping traditions of the Hemshin people, an ethnic minority originating from Armenia, are both evolving and at risk of vanishing.
Technology
New bee icons – animated and still – for public use
(Twitter, iBartomeus @ibartomeus) “New Bee Icons -> Along with Jose Luis Ordóñez, we decided to make available under CC-BY-NC the collection of bee icons we used to make our video. I am sure this will be useful to the academic community #OpenScience” The icon collection.
One More Thing…
From Olli Loukola @LoukolaOlli via Twitter:
Chimpanzees using sticks to get food = sophisticated tool use
Bumblebees using sticks to get food = simple fine motor activity
#speciesism