An emerging conservation threat is having a profoundly negative effect on the nation’s most important pollinators, and by extension, the birds, amphibians and other wildlife that live in their habitat areas. This threat comes from the expanding use of the most widely used insecticides, the neonicotinoids.
Despite the growing body of evidence confirming their toxicity to beneficial bees and birds that are found in agricultural habitat areas, this group of pesticides has rocketed to the top of the list for sales not just in the United States, but globally as well. The neonicotinoid insecticides now account for more than one quarter of the entire global market, and the prevalence of their use is growing.
“Neo-nics,” as they are sometimes called, have been around a relatively short time — only since the 1990s. However, they were the first new major class of insecticides developed in the past 50 years, and they replaced classes of insecticides such as the organophosphates and carbamates that were known to have serious human and environmental health impacts and which were implicated in the killing of songbirds, the decline of eagles, osprey and hawks, and the prevalence of several neurological disorders in humans.
Nicotine has long been known as a substance possessing insecticidal properties, and it has also been shown to have less toxicity to mammals than it does to insects. However, early formulations of insecticides containing nicotine compounds, or nicotinoids, were unsuccessful for a variety of reasons. It was not until breakthroughs in the 1980s that new formulations known as the neonicotinoids were developed and then widely produced and marketed. They now account for fully 80 percent of all seed treatments as well as more than 25 percent of all other insecticides.
A Cause for Concern
Despite the popularity and effectiveness of neonicotinoid insecticides, there are serious questions regarding their impacts, particularly their long-term persistence in the environment, their impact on aquatic systems in which effects are magnified by surface runoff, and “their cumulative and largely irreversible mode of action in invertebrates,” as noted in a 2013 report by the American Bird Conservancy. All of these factors, and the growing belief that the neonicotinoids are implicated in Colony Collapse Disorder (CCD) in honeybees, have led to urgent calls for action by national environmental and conservation organizations such the Center for Food Safety, the Center for Environmental Health, the American Bird Conservancy and beekeeper groups nationwide.
A coalition of groups filed an emergency petition with the Environmental Protection Agency (EPA) to suspend the use of one of the neo-nics, clothianidin, which is believed to kill birds as well as beneficial bees, but it was denied by the EPA. Lawsuits have been filed, and in 2013, Reps. John Conyers and Earl Blumenauer introduced the “Saving America’s Pollinators Act,” H.R. 2692, but it failed to make it out of committee in the House of Representatives. This bill would require the EPA to suspend the registration of neonicotinoids, conduct a review and do field studies, and for the EPA and the Department of the Interior to monitor the adverse impacts on birds, bats, bees and other beneficial insects. The European Union, by contrast, recently adopted a two-year suspension of the use of neonicotinoids while studies to determine impacts on native bees and other wildlife species are completed.
The Impacts to Natural Resources and Wildlife
The effects of neonicotinoids on bees are becoming more well-documented. What is known is that the neo-nics are systemically absorbed into plant tissue and can be present as residues in leaves, flowers and pollen. Furthermore, neo-nics can be found in plant tissues and soils up to six months after application, and residue concentrations can reach lethal levels in some plants for some species. They are particularly deadly to honeybees and bumblebees as well as a number of butterfly species. Most troubling is that some manufacturers’ recommended application rates may cause consumers to apply concentrations at up to 100 times those used in agricultural applications without realizing the impact the product will have on bees or other pollinating insects.
Neo-nics’ persistence in the environment is causing researchers to take a closer look at the effects on aquatic ecosystems particularly, and on birds generally. It is known that one kernel of corn treated with one type of neonicotinoid is enough to kill a songbird if ingested. Amphibians appear to be hard-hit as well, as they take the brunt of concentrated residues contained in surface runoff into ponds, wetlands and streams. In addition, emerging evidence shows that the registration of the neonicotinoids did not seem to take into full consideration the impacts on the reproductive cycles of birds and other sublethal impacts. Studies have shown birds that consume one-tenth of an affected seed per day during egg-laying season may suffer negative impacts to reproduction. Seed treatments seem to have the largest effect on birds because there is inevitably some percentage of spilled seed or some portion of the crop that is not fully covered by soil.
A Course of Action for Parks
Pollinators are important for parks, and parks are vital to pollinators. Park and recreation agencies should make every effort to learn more about this class of insecticides and to assess the potential benefits and hazards of applying neonicotinoid insecticides in parks — on golf courses, in horticultural displays, to agricultural areas and in any other areas where pest management is practiced, with particular care to the potential effects on bees, songbirds and aquatic organisms.
At a minimum, certified applicators and managers who have responsibility for directing other staff in application of insecticides should become aware of the potential short-term and long-term dangers of neonicotinoid insecticides. Further, even if agencies are practicing Integrated Pest Management (IPM) strategies, it is important to take into consideration that new pre-emptive application strategies that call for applying insecticides to turf or as seed treatments are taking precedence over IPM methods. Such strategies call for applying pesticides in advance of any specific evidence of insect damage, rather than selectively and in response to damage. With neonicotinoids, this practice can cause long-term unintended harm to bees and other pollinators as well as damage to aquatic ecosystems. Parks need to be protectors of our pollinators, and better knowledge about the insecticides we use will help accomplish that goal.
Richard J. Dolesh is NRPA’s Vice President of Conservation and Parks.