Sulfoxaflor Continues to be a Killer

CATCH THE BUZZ Michele Colopy, Program Director, Pollinator Stewardship Council, Inc. July 16, 2019


EPA’s announcement1 to expand the use of Sulfoxaflor means expanded loss of managed and native pollinators.  Beekeepers, whose honey bees provide the essential agriculture pollination service for our food supply, have suffered colony losses of 40-90% annually the past ten years.  A horizon scan of future threats and opportunities for pollinators and pollination placed the chemical Sulfoxomine (sulfoxaflor) in the top six priority issues that globally threaten the agricultural and ecological essential service of pollination.

Six high priority issues 
1: corporate control of agriculture at the global scale
2: sulfoximine, a novel systemic class of insecticides (which is sulfoxaflor)
3: new emerging RNA viruses
4: increased diversity of managed pollinator species
5: effects of extreme weather events under climate change
6: positive effects of reduced chemical use on pollinators in non-agricultural settings2

The Pollinator Stewardship Council has expressed our concerns about the registration of Sulfoxaflor for reduced use, and for emergency exemptions. In our legal action about the registration of Sulfoxaflor, the Ninth Circuit Court found in their review that important data concerning the effect upon honey bees from Sulfoxaflor was incomplete.  EPA adjusted the pesticide label, reducing the bee attractive crops on which the chemical could be applied.  However, let’s be concise: the active ingredient, Sulfoxaflor, is toxic to chewing and sucking insects.  Honey bees and other pollinators are chewing and sucking insects.

With over one billion pounds of pesticides used in the U.S. annually,3 the EPA claims there are “few viable alternatives for sulfoxaflor.”   Research is showing the “viable alternatives” are to restore the health of agricultural soils so the beneficial insects and fungi can return and protect the crops.  “Regenerative Agriculture is a system of farming principles and practices that increases biodiversity, enriches soils, improves watersheds, and enhances ecosystem services.”4 By restoring the health of soils, we restore the health of plants, and we restore the health of beneficial insects like pollinators.

In a study conducted from 2004-2009 by the University of Idaho on various methods of control for lygus bugs in alfalfa  it was observed the Peristenus howardi  (and similar species) parasitized lygus bugs ranging from 5% to 80%.   The primary goal of that research was “to conduct studies investigating the feasibility of enhancing lygus bug management in alfalfa seed through several complementary approaches. The individually low levels of lygus bug management provided by newer, more selective alternative compounds and that provided by natural enemies of lygus bugs will be combined in an attempt to provide acceptable levels of lygus management in large plots of alfalfa grown for seed. We will attempt to further enhance natural enemy numbers in these studies through modification of crop habitat (border treatments).”5

These very “border treatments” will now be under threat of contamination from Sulfoxaflor applications, degrading their prospective evidence-based solution of providing habitat for natural predators of crop pests.  Similar border treatments in other crops would be as beneficial.  But the 12-49 feet of blooming crop border could be contaminated with the bee toxic pesticide, Sulfoxaflor.  Blooming field borders support true IPM (Integrated Pest Management), providing costs savings to the farmer in reduced chemical inputs, and conserving crop losses through the pest management of beneficial insects.

While Pollinator Stewardship Council appreciated the initial revised Sulfoxaflor label as an improvement over the previous label, limiting the use of the pesticide after bloom on mostly non-bee attractive crops,  Sulfoxaflor is still a bee toxic pesticide with unknown synergisms when tank-mixed.  With little to no data on the degradates of Sulfoxaflor, and no research of tank mixes with Sulfoxaflor, it remains a bee toxic pesticide contaminating bee forage through drift and residue.  With the expansion of the use of Sulfoxaflor EPA is ignoring the threats to essential agricultural and ecological pollination services, and to the very livelihood of beekeepers tasked with providing the managed honey bees to pollinate our crops.

1 EPA Registers Long-Term Uses of Sulfoxaflor While Ensuring Strong Pollinator Protection,

2 Brown MJF, Dicks LV, Paxton RJ, Baldock KCR, Barron AB, Chauzat M, Freitas BM, Goulson D, Jepsen S, Kremen C, Li J, Neumann P, Pattemore DE, Potts SG, Schweiger O, Seymour CL, Stout JC. 2016. A horizon scan of future threats and opportunities for pollinators and pollination. PeerJ 4:e2249

3 Pesticides Use and Exposure Extensive Worldwide, Michael C.R. Alavanja, Dr.P.H., Rev Environ Health. 2009 Oct–Dec; 24(4): 303–309. ,

5 MANAGEMENT OF LYGUS SPP. (HEMIPTERA: MIRIDAE) IN ALFALFA SEED, University of Idaho,  National Institute of Food and Agriculture, 2004-2009,

EPA Re-registers Sulfoxaflor for Crop Use, But Restricts Use on Some Crops

CATCH THE BUZZ     October 17, 2016

WASHINGTON, Oct. 15, 2016 – New measures to protect honey bees and fewer crop uses are included in the latest registration of sulfoxaflor, a Dow AgroSciences insecticide that was canceled last year.

The Environmental Protection Agency announced the registration decision Friday, 13 months after the 9th Circuit Court of Appeals found that EPA lacked sufficient data to show that it was not harmful to honey bees.

EPA canceled the registration in November, but subsequently approved it for use on cotton and sorghum under Section 18 of the Federal Insecticide, and Rodenticide Act, which allows pesticides to be used to protect crops in “emergency” situations even if the pesticide is not registered for that crop use. It proposed the new registration in May.

The final decision largely tracks that proposal, eliminating some crops that had been included in the previous registration. Those include “indeterminate blooming crops” such as citrus, cotton, soybeans, strawberry, and gourds such as squash and pumpkin.

EPA said it is registering sulfoxaflor, sold under the trade names Transform and Closer, for use “only on crops that are not attractive to pollinators or for crop-production scenarios that minimize or eliminate potential exposure to bees.”

“For those crops that are included and that are bee-attractive, sulfoxaflor will be allowed only post bloom, when bees are not expected to be present, and will not be allowed on any crops grown for seed, including turf,” EPA said. “These restrictions practically eliminate exposure to bees in the field, which reduces the risk below EPA’s level of concern such that no additional data requirements to protect bees are triggered.”

EPA said it also is prohibiting application if wind speeds exceed 10 mph and will require a 12-foot on-field buffer on the down-wind edge to protect bees from spray drift if there is blooming vegetation bordering the treated field. The agency also will prohibit tank mixing of sulfoxaflor with pesticides that have shown evidence of synergistic activity with sulfoxaflor.

  1. A. Van Steenwyk, a research entomologist who commented on the tank-mix proposal for Dow AgroSciences, said that “since sulfoxaflor has a unique mode of action that would limit the development of resistance, I would not expect to see any synergistic effects with sulfoxaflor with any tank mix for the unforeseeable future.”

A list of the crops approved for sulfoxaflor use follows.

Not Bee Attractive:

  • Barley, triticale, wheat
  • Turf grass

Harvested Before Bloom:

  • Brassica leafy vegetables
  • Bulb vegetables
  • Leafy vegetables (non-Brassica) and watercress
  • Leaves of root and tuber vegetables
  • Root and tuber vegetables

Bee Attractive, Applications Allowed Post-Bloom Only:

  • Berries (grape, blueberry, cranberry)
  • Canola
  • Fruiting vegetables (tomato, pepper, eggplant) and okra
  • Pome fruit
  • Ornamentals
  • Potato
  • Stone fruit
  • Succulent and dry beans
  • Tree nuts and pistachio

EPA said it would consider the other uses “at a later date as data become available to support those uses.”

The Center for Biological Diversity said it was disappointed in the decision, calling sulfoxaflor a “dangerous bug-killer” and saying the agency had refused to examine its effects on threatened and endangered species. CBD also called the approval “a step in the right direction because it prohibits the use of sulfoxaflor on certain blooming crops, such as cotton, among other measures.”

In its response to public comments, EPA said that delaying sulfoxaflor’s registration to complete an Endangered Species Act consultation would not be in the public’s or the environment’s best interest because it would divert resources from “evaluating and regulating, where appropriate, what the EPA believes to be more toxic compounds, that . . . pose greater risk to endangered species than does sulfoxaflor.”

A Win for Bees

Pesticide Action Network -  North America    By Paul Towers   November 27, 2015

The California State Beekeepers Association was buzzing about pesticides at their annual convention in Sacramento last week. And with good reason.

Just days before, EPA took the rare step of banning a bee-toxic insecticide. For an agency that has been really slow to take meaningful bee-protective action, dragging out both scientific analysis and much needed policy shifts, this was a very welcome move.

The agency's decision to pull sulfoxaflor — manufactured by Dow — was largely a response to litigation brought on by beekeepers. And the courts ruled EPA had relied on "flawed and limited data" to approve the pesticide's registration in the first place, citing the “precariousness of bee populations.

A close cousin to neonicotinoid pesticides, sulfoxaflor is pervasive in treated crops and acts on the same receptors in bee brains. It was also one more in the line of new bee-toxic chemicals that EPA and manufacturers have been hustling toward approval.

Pulling sulfoxaflor off the market will mean the product can no longer be applied to nuts, fruits and vegetables around the country — some of the very crops that rely on bees for pollination. While EPA missed an important opportunity to stop the export of this troublesome pesticide, it's still a clear win for bees and beekeepers in the U.S.

Focus on the pesticide problem:

Despite federal officials moving slowly to address the wider spectrum of bee-harming pesticides, beekeepers are keeping the pressure on. Darren Cox, a commercial beekeeper from Utah and president of the American Honey Producers Association, highlighted the priority and urgency of the pesticide problem at the California convention:

"Our beekeeper members have made it clear that pesticides are their number one issue of concern. Despite efforts to blame mites or the practices of beekeepers, the reality is that widespread pesticide use, particularly systemic pesticides, poses a significant threat to our livelihood."

And that may be why remarks from state officials at the same convention didn’t land very well. One representative from the CA Department of Food and Agriculture, in speaking to convention-goers, placed virtually all responsibility on beekeepers; she encouraged them to register all their hives with local and state officials so they would have a record of hive locations. And she told beekeepers to pick up and move bee operations when they encounter a potential threat from nearby pesticide applications — a wholly unrealistic option.

These approaches simply ignore the reality of lingering residues in crops, soil and water — not to mention threats to native bees and other pollinators that can't be moved. More importantly, they let pesticide manufacturers like Bayer off the hook; these corporations should be held accountable for the impact of their pesticide products. 

These approaches simply ignore the reality of lingering residues in crops, soil and water — not to mention threats to native bees and other pollinators that can't be moved. More importantly, they let pesticide manufacturers like Bayer off the hook; these corporations should be held accountable for the impact of their pesticide products.

Scientists also spoke up at the conference, cutting through it all. Judy Wu, a researcher with the University of Minnesota Bee Lab, focused her talk on the harmful impacts of neonicotinoids on queen bees. She summed up the situation like this:

“Science has to be narrowly focused, but policy needs to address the bigger picture — an overuse and dependency on pesticides.”

EPA took a good step by halting use of sulfoxaflor, but it shouldn't have been approved in the first place. And there is clearly more work to be done to protect bees, beekeepers and sustain our agricultural economy.

Read at:

Court Agrees: Sulfoxaflor Registration Based on Flawed and Limited Data

CATCH THE BUZZ - September 15, 2015

The Pollinator Stewardship Council is pleased with the Ninth Circuit Court of Appeals Opinion concerning the registration of sulfoxaflor.  Our argument, presented by Earthjustice attorney, Greg Loarie, addressed our concerns that EPA’s decision process to unconditionally register Sulfoxaflor was based on flawed and limited data, and the Ninth Circuit Court of Appeals agreed with us.

Beekeepers WON!  The registration of a highly toxic pesticide to honey bees has been revoked due to the flawed and limited data collected and reviewed by EPA.

We can protect crops from pests and protect honey bees and native pollinators.  To do this, EPA’s pesticide application and review process must receive substantial scientific evidence as to the benefits of a pesticide, as well as the protection of the environment, especially the protection of pollinators. Sulfoxaflor was “registered” for use on cotton, soybeans, citrus, pome/stone fruits, nuts, grapes, potatoes, vegetables, and strawberries.

“Without sufficient data, the EPA has no real idea whether sulfoxaflor will cause unreasonable adverse effects on bees, as prohibited by FIFRA. Accordingly, the EPA’s decision to register sulfoxaflor was not supported by substantial evidence.” (Pollinator Stewardship Council v. U.S. Environmental Protection Agency; No. 13-72346, pg. 24, 25; Sept. 10, 2015)

“I am inclined to believe the EPA instead decided to register sulfoxaflor unconditionally in response to public pressure for the product and attempted to support its decision retroactively with studies it had previously found inadequate.  Such action seems capricious.” (Pollinator Stewardship Council v. U.S. Environmental Protection Agency; No. 13-72346, pg. 33; Sept. 10, 2015)

Read at:

Another Bee Disaster Waiting to Happen

Beyond Pesticides For Release: January 14, 2013

Sulfoxaflor Proposed Pesticide Registration Decision Available for Public Comment 

The EPA is seeking comment on its proposed decision to conditionally register the new active ingredient sulfoxaflor, formulated as a technical product and two end-use products for use in production agriculture. The proposed use sites are barley, bulb vegetables, canola, citrus, cotton, cucurbit vegetables, fruiting vegetables, leafy vegetables, low growing berry, okra, ornamentals (herbaceous and woody), pistachio, pome fruits,  root and tuber vegetables, small fruit vine climbing (except fuzzy kiwifruit), soybean, stone fruit, succulent, edible podded and dry beans, tree nuts, triticale, turfgrass, watercress and wheat.  

The agency finds this decision to be in the public interest because the registration of this pesticide for use on these crops will provide growers with a new pest management tool to kill a broad spectrum of piercing/sucking insects, including species that are difficult to control. For example, the agency granted a Section 18 Emergency Exemption in Arkansas, Mississippi, Tennessee and Louisiana for use of unregistered sulfoxaflor on cotton to control the tarnished plant bug, an insect that has developed resistance to alternative registered pesticides. Sulfoxaflor is also a valuable new tool for managing the development of pesticide resistance. 

The EPA’s proposed decision document and supporting documents will be posted at under EPA-HQ-OPP-2010-0889 for a 30-day public comment period.


Beyond Pesticides

TAKE ACTION:  Tell EPA- Submit a Comment

EPA is set to repeat an ecological calamity by registering the new pesticide sulfoxaflor, knowing that the chemical is highly toxic to bees, and without sufficient evidence of its safety. Tell EPA not to allow the decline of more pollinators, and withdraw sulfoxaflor’s registration.