Editor’s Note: Join Dr. Joe Bischoff of AmericanHort and Lin Schmale of the Society of American Florists (SAF) at AmericanHort’s Cultivate’14 on Saturday, July 12 from 10:45 a.m. to 11:30 a.m., where they’ll present “Neonicotinoids: Cutting Through The Clutter.”
Bischoff and Schmale will present the facts, as research has demonstrated them, and how to use neonicotinoids effectively and responsibly with minimal non-target effects.
Most of the uproar regarding the use of neonicotinoid insecticides and their potential impact on pollinators, at least as it relates to our industry, began last spring when approximately 50,000 bees were killed in Oregon as the result of a dinotefuran application. It was believed at the time and later confirmed by an Oregon Department of Agriculture investigation that the applicator did not properly follow the EPA-approved label and sprayed the insecticide on linden trees that were in flower and actively being visited by bees – a clear off-label application.
This event happened just 20 miles down the road from the headquarters of the Xerces Society, an organization dedicated to the conservation of invertebrates, which includes insects. The Xerces Society captured the moment and significant media attention by holding a mock-funeral for the bees, making the errant application a symbol for anti-pesticide activist groups everywhere.
What Are Neonicotinoids?
Neonicotinoids are a class of insecticides (e.g., clothianidin, dinotefuran, imidacloprid, thiacloprid) first developed in the 1990s. As the name suggests, they are a new take on a naturally found chemical — “neo” from the Greek root meaning “new” and “nicotinoids” referring to nicotine. Essentially, it is a chemical that is an altered version of nicotine but exhibits low toxicity to mammals, including humans, while maintaining toxicity to insects.
Growers and landscapers use them extensively in defending trees, shrubs and other plants against destructive invasive species like the Japanese Beetle, Hemlock Woolly Adelgid and Asian Longhorned Beetle. Greenhouse growers use them as part of management strategies to deal with invasive and often chemical-resistant whitefly species and other pests.
In some cases, neonicotinoids are approved regulatory treatments for certification and interstate movement of nursery and greenhouse crops. When compared with some of the older chemistries in our arsenal, neonicotinoids represent a tremendous advancement in effectively controlling problem insects, while being safer for humans and exhibiting far less impact on non-target insects (including bees).
Why Are We Worried About Bees Suddenly?
Non-target insect kills do occur occasionally, and the event in Oregon must act as a reminder of our industry’s need to be responsible stewards of our lands and the tools at our disposal. However, some groups are trying to capitalize on these few unfortunate events and erroneously connect them to concerns regarding bee decline, bee health and Colony Collapse Disorder (CCD). These are much broader issues, which are very real, but are not the direct result of our industry’s use of neonicotinoids.
The term “bee decline” pertains to the general reduction in the number of managed European honey bee (Apis mellifera) colonies in the United States in the decades following the end of World War II. However, much of the decline is in direct relation to our changing economy and population distribution over the last 60+ years, with fewer people working in agriculture and our population increasingly concentrated around metropolitan areas, where beekeeping is not particularly common.
Also, while the focus on colony management used to be on honey production, it has shifted towards pollination services. These services require that colonies are often shipped great distances in order to pollinate crops for fruit and vegetable production. Thus, much of the general decline in colony numbers simply has to do with a changing beekeeper industry.
Colony Collapse Disorder (CCD) is an unexplained phenomenon where large numbers of bees go missing or abandon what would otherwise appear to be a generally healthy colony. The term was first used in 2006 when some beekeepers reported 30 to 90 percent losses for unknown reasons. Large losses of this size have happened before with reports of a “disappearing disease” occurring as far back as 1869.
Since 2006, losses have stabilized but are still historically high with keepers regularly reporting losses averaging 33 percent a year. But these elevated losses are more reflective of winter loss and not the unexplained disappearance of workers from the colony.
This directs us to look at the bigger challenges facing beekeepers — not so much CCD, which was mostly a 2006 to 2007 phenomenon — but instead the concerns about bee health and the stresses that have led to higher winter losses.
Bee health was a focus of a hearing held by the U.S. House of Representatives Agriculture Committee’s Subcommittee on Horticulture, Research, Biotechnology and Foreign Agriculture on April 29. During the hearing, we heard about the bevy of challenges bees face, including habitat loss, lack of genetic diversity, reduced foraging options, pathogens and pesticides. However, the overwhelming consensus was that the greatest factor impacting bee health was the arrival of the Varroa mite.
One of the witnesses was Dr. Jeff Pettis, Research Leader of the USDA’s Agricultural Research Service Bee Research Laboratory. In his testimony, Dr. Pettis succinctly described what the arrival of the new parasite and the viruses it carries meant to the beekeeper industry as, “when Varroa destructor was first found in the United States in 1987, beekeepers managed more than 3 million colonies for crop pollination and their winter losses were typically about 10 percent to 15 percent. Today, beekeepers are having trouble maintaining 2.5 million managed colonies; winter losses are averaging more than 30 percent a year.” He referred to the mite as “a modern honey bee plague.”
Dr. Pettis’ testimony on the impact of the Varroa mite and the pathogens it vectors are reflected in other comprehensive reports published within the last 18 months, including the USDA’s National Stakeholder report on honey bee health, as well as reports from the United Kingdom’s Department for Environment, Food & Rural Affairs and the Australian Government’s Pesticides and Veterinary Medicines Authority.
Easier To Point Fingers Than Find Solutions
Bee health is a complicated issue with many factors at play. However, some organizations and interest groups that are focused on pursuing a pesticide-free agenda are trying to conflate the acute kills with the overall concerns of bee population health and are quick to employ terms like bee decline and CCD in conjunction with pesticide use, despite the lack of supporting evidence.
So how do we shift the conversation to make it more reflective of the scientific evidence and tackle the very real concerns about bee health? As an industry, we need to encourage the research community to pursue its work on this issue without bias and identify the necessary steps to alleviate concerns about bee health. As stated above, pesticides aren’t a non-actor in the concerns about bee health, and we need to be proactive in identifying how to effectively deploy neonicotinoids to maximize their pest mitigation benefits while limiting their impacts on pollinators — looking to the research community to provide data that reflects real-world situations.
Questions about neonicotinoid concentrations in pollen and nectar remain. The studies that are published and often referenced are largely based on dosing or force feeding and are not reflective of what bees would encounter in the environment or landscape. In some cases, concentrations from plants like ash trees or other wind-pollinated plants, which would not be visited by bees, are referenced. These studies do not help to answer the important questions we have but only serve to further confuse the situation and encourage an agenda of misinformation.
What Can We Do Now?
It is important that we are informed and prepared to talk about the issue of pesticides, pollinators and the overarching concerns of bee health in a calm and clear manner. This is a topic where emotions can run high, and part of our role should be in explaining the need for balance and scientifically based solutions. Neonicotinoids are a useful and safe tool, but we must also be sensitive to those that are concerned about bee health and do what we can to alleviate it while informing them that the issue is not pesticide-based.
There isn’t a lot we can do in the horticulture industry to help beekeepers deal with Varroa mites, the pathogens they carry or the lack of genetic diversity of the bees themselves. However, we can try to take steps to limit the exposure of bees to pesticides — after all, every little bit helps. The place to start would be by visiting the Pesticide Environmental Stewardship (PES) website (http://pesticidestewardship.org). The information included on the PES site is the result of a federal, academic and industry collaboration to summarize and provide easy access to the general principles of pesticide stewardship.
The most important thing is always following the EPA-approved label. Like the carpenter’s adage, measure twice and cut once, an applicator should read the label multiple times and make sure he understands it before making the application. Always remember, the EPA-approved label is the law.