Pesticides Deliver a One-Two Punch to Honey Bees

Phys.Org By Society of Environmental Toxicology and Chemistry August 5, 2019

Researchers conduct semi-field experiments on honey bees. Credit: Lang Chen

Researchers conduct semi-field experiments on honey bees. Credit: Lang Chen

Adjuvants are chemicals that are commonly added to plant protection products, such as pesticides, to help them spread, adhere to targets, disperse appropriately, or prevent drift, among other things. There was a widespread assumption that these additives would not cause a biological reaction after exposure, but a number of recent studies show that adjuvants can be toxic to ecosystems, and specific to this study, honey bees.

Jinzhen Zhang and colleagues studied the effects on honey bees when adjuvants were co-applied at "normal concentration levels" with neonicotinoids. Their research, recently published in Environmental Toxicology and Chemistry, found that the mixture of the pesticide and the adjuvant increased the mortality rate of honey bees in the lab and in semi-field conditions, where it also reduced colony size and brooding.

When applied alone, the three pesticide adjuvants caused no significant, immediate toxicity to honeybees. However, when the pesticide acetamiprid was mixed with adjuvants and applied to honeybees in the laboratory, the toxicity was quite significant and immediate. In groups treated with combined pesticide-adjuvant concentrates, mortality was significantly higher than the control groups, which included a blank control (no pesticide, no adjuvant, only water) and a control with only pesticide (no adjuvant). Further, flight intensity, colony intensity and pupae development continued to deteriorate long after the application comparative to the control groups.

Zhang noted that this study, "contributed to the understanding of the complex relationships between the composition of pesticide formulations and bee harm," and stressed that "further research is required on the environmental safety assessment of adjuvants and their interactions with active ingredients on non-target species."

https://phys.org/news/2019-08-pesticides-one-two-honey-bees.html

Scientists Say Agriculture is Good for Honey Bees, at Least in Tennessee

CATCH THE BUZZ By: Ginger Rowsey, University of Tennessee Institute of Agriculture July 11, 2017

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In a recent study, researchers with the University of Tennessee Institute of Agriculture found the overall health of honey bees improved in the presence of agricultural production, despite the increased exposure to agricultural pesticides. – Credit: Scott Stewart

While recent media reports have condemned a commonly used agricultural pesticide as detrimental to honey bee health, scientists with the University of Tennessee Institute of Agriculture have found that the overall health of honey bee hives actually improves in the presence of agricultural production.

The study, “Agricultural Landscape and Pesticide Effects on Honey Bee Biological Traits” which was published in a recent issue of the Journal of Economic Entomology, evaluated the impacts of row-crop agriculture, including the traditional use of pesticides, on honey bee health. Results indicated that hive health was positively correlated to the presence of agriculture. According to the study, colonies in a non-agricultural area struggled to find adequate food resources and produced fewer offspring.

“We’re not saying that pesticides are not a factor in honey bee health. There were a few events during the season where insecticide applications caused the death of some foraging bees,” says Mohamed Alburaki, lead author and post-doctoral fellow with the University of Tennessee Department of Entomology and Plant Pathology (EPP). “However, our study suggests that the benefits of better nutrition sources and nectar yields found in agricultural areas outweigh the risks of exposure to agricultural pesticides.”

Alburaki and fellow researchers established experimental apiaries in multiple locations in western Tennessee ranging from non-agricultural to intense agricultural production. Over the course of a year, colonies were monitored for performance and productivity by measuring colony weight, brood production and colony thermoregulation. Colony thermoregulation, or the ability to maintain an optimal temperature within a hive, is an important factor in brood development and the health of the resulting adult bees.

According to the study, hives located in areas with high to moderate agricultural vegetation grew faster and larger than those in low or non-agricultural areas. Researchers suggest the greater population sizes enabled better colony thermoregulation in these hives, as well.

Meanwhile, bees located in a non-agricultural environment were challenged to find food. Although fewer pesticide contaminants were reported in these areas, the landscape did not provide sustainable forage. In fact, during the observations, two colonies in the non-agricultural areas collapsed due to starvation.

Disruptions and fluctuations in brood rearing were also more notable in a non-agricultural environment. Interestingly, brood production was highest in the location that exhibited a more evenly distributed mix of agricultural production, forests and urban activity.

“One possible explanation for this finding could be the elevated urban activity in this location,” says Alburaki. “Ornamental plantings around homes or businesses, or backyard gardens are examples of urban activity that increase the diversity of pollen in an area. Greater pollen diversity has been credited with enhancing colony development.”

Researchers also evaluated trapped pollen from each colony for pesticide residues. Low concentrations of fungicides, herbicides and insecticides were identified, but at levels well below the lethal dose for honey bees. Imidacloprid was the only neonicotinoid detected, also at sub-lethal levels.

Agricultural pesticides, particularly neonicotinoids, are considered by some to be a key factor in declining honeybee populations. The UTIA study found that higher exposure to pesticides in agricultural environments did not result in measurable impacts on colony productivity.

“We train agricultural producers on careful selection and conscientious application of pesticides to reduce bee exposure,” says Scott Stewart, Integrated Pest Management Specialist with UT Extension, “but it’s becoming more clear that the influences of varroa mite and food availability are more important factors in honey bee health than agricultural pesticides.”

https://www.beeculture.com/catch-the-buzz-scientists-say-agriculture-is-good-for-honey-bees-at-least-in-tennessee/?utm_source=Catch+The+Buzz&utm_campaign=76d491d752-Catch_The_Buzz_4_29_2015&utm_medium=email&utm_term=0_0272f190ab-76d491d752-256252085

Sulfoxaflor Continues to be a Killer

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

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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,

https://www.epa.gov/newsreleases/epa-registers-long-term-uses-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 https://doi.org/10.7717/peerj.2249https://peerj.com/articles/2249/?utm_source=TrendMD&utm_campaign=PeerJ_TrendMD_1&utm_medium=TrendMD

3 Pesticides Use and Exposure Extensive Worldwide, Michael C.R. Alavanja, Dr.P.H., Rev Environ Health. 2009 Oct–Dec; 24(4): 303–309. ,  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946087/

http://www.regenerativeagriculturedefinition.com/

5 MANAGEMENT OF LYGUS SPP. (HEMIPTERA: MIRIDAE) IN ALFALFA SEED, University of Idaho,  National Institute of Food and Agriculture, 2004-2009, http://reeis.usda.gov/web/crisprojectpages/0202036-management-of-lygus-spp-hemiptera-miridae-in-alfalfa-seed.html

https://www.beeculture.com/catch-the-buzz-sulfoxaflor-continues-to-be-a-bee-killer/?utm_source=Catch+The+Buzz&utm_campaign=22e73f1b43-Catch_The_Buzz_4_29_2015&utm_medium=email&utm_term=0_0272f190ab-22e73f1b43-256252085