Nearly every week, and sometimes daily, articles appear in the Environmental section of major newspapers about colony collapse disorder (CCD) and other pollinator and bird maladies. This year is no exception, continuing where it ended last year, with reports of massive bee disappearances and death, in some cases up to 40-50% of the bee hives used in agriculture pollination and production.
Most studies about pollinator decline focus on the status and decline of bees. Bees are responsible for the majority of pollination, servicing nearly 70% of flowering plants, many of them supplying our fruits, vegetables, seeds and nuts. Bees are important to the food supply, responsible for pollinating a third of the food we eat in the US, and a major share of the world's food crops pollinated by all animals, which includes birds, butterflies, wasps, flies, other insects and bats. Additionally, the fruits and seeds of plants pollinated by bees and other pollinators are important part of the diet for 25% of birds. Globally, researchers have estimated the value of pollinators at €153 billion, no small sting.
Three reasons are usually given for the decline of bees: lack of natural bee habitat and diminishing diversity of pollen sources, disease-carrying parasites such as the Varroa mite, and the use of insecticides, particularly the use of a group of chemicals called neonicotinoides, or neonics, an insecticide modeled after the natural insecticide, nicotine.
The decline of bees and other pollinators has turned into a complicated and controversial issue. Certainly, lack of habitat and pollen diversity has a great deal to do with pollinator decline, as well as the Varroa mite. In several areas of the US and other countries, Varroa destructor and Varroa jacobsoni, have been credited with the death of up to 44% of bee hives since the mites introduction in the 1990's, according to the North Carolina State University Apiculture Bulletin 2.03.
Varroa mites are the natural preditor of Asian honeybees, Apis cerana. The first US infestation of European honeybee hives by the varroa mite was reported in 1987. Their introduction was traced to a shipment of bees imported from Brazil, with Florida the most likely point of entry, according to BeeSource.
Since the introduction of neonicotinoids in in 1992, many have begun pointing their finger at these toxic systemic chemicals as a major contributor to bee and pollinator decline. Widely used in agriculture and ornamental landscapes, they are absorbed by the plants, making the entire plant toxic to insects. The major neonics are imidacloprid (Admire®, Advantage®, Gaucho®, Merit®, Premise®, Touchstone®), clothianidin (Acceleron®, Arena®, Belay®, Celero®, Clutch®, Nipsit Inside®, Poncho®), dinotefuran (Alpine®, Dinotefuran®, Safari®, Scorpion®, Venom®), thiamethoxam (Cruiser®, Platinum®) and acetamiprid (Acetamiprid®, Assail®, Tristar®). Hundreds of registered neonic products are available for agriculture and home use. Syngenta (based in the UK) and Bayer (based in Germany) are two of the major companies that produce neonics. All of these neonics have a high toxicity to wildlife, except for acetamiprid, which has a moderate toxicity, according to a study by Frederick Fishel, Director of Pesticide Information Office at the Florida Cooperative Extension Service.
Vast acreage of single crops all coming into flower at the same time demand a huge supply of pollinators, and even with commercial hives traveling the country going from one crop to the next, the demand is just barely being met. Before CCD, bee keepers would experience 10 to 15% loss of hives over winter. In 2005 when CCD was first noticed, the rate of loss jumped to 30-35%, with this year, losses have taken another big jump. A recent article in the New York Times paints an even gloomier picture, with up to 40-50% of hives wiped out this year. Some beekeepers report the loss in hives up to 65%, according to MinnPost.
Neonicotinoids were developed to take the place of chemicals considered to be more harmful. Crops are sprayed with many herbicides and insecticides. Plants and pollinators are subjected to an incredible number and combinations of chemicals. But many are now beginning to wonder about their safety. “Eric Mussen, an apiculturist at the University of California, Davis, said analysts had documented about 150 chemical residues in pollen and wax gathered from beehives.
“Where do you start?” Dr. Mussen said. “When you have all these chemicals at a sublethal level, how do they react with each other? What are the consequences?” (NYT)
Without Pollinators – Hand Pollination
Many people are sounding fears of a future time without our main pollinators. In China, after stepping up their production of pears, peaches and apples and increasing the use of pesticides, they found there just weren't enough pollinators to do the job. Chinese farmers must enlist the aid of villagers, climbing trees to hand pollinate the blooms each spring.
An article in the Texas Bee Watchers illustrates how this began: “ . . . an outbreak of pear Psylla (Pear lice) began. The Psylla are a serious pest of pears. This outbreak was treated by intense spraying with insecticide. In fact, every time an insect appeared on the income-producing pear crop, farmers would spray–sometimes as much as 12 times during each production season. Unwilling to risk the loss of their pear trees–and the subsequent loss of income–the farmers continued to intensively spray their pear trees–killing the pest insects. The honeybees, once common, began to disappear. The intensive spraying killed all insects, including the honeybees.”
Evidence Against Neonics Starts to Mount
Because of the increasing debate over neonicotinoids, and to separate opinion from fact, the Xerces Society prepared a report on the effects of neonicotinoids on pollinators, especially their effect on bees. Their report, Are Neonicotinoids Killing Bees? A Review of Research into the Effects of Neonicotinoid Insecticides and Bees, with Recommendations for Action, by Jennifer Hopwood, Mace Vaughan, Matthew Shepherd, David Biddinger, Eric Mader, Scott Hoffman Black and Celeste Mazzacano was issued in 2012.
A summary of the report notes that neonicotinoids are absorbed into the plant and therefore can be present in pollen and nectar, contaminates adjacent weeds and wildflowers, and persists in the plants and soil for a “very long period of time”, up to six years, allowing plants in subsequent years to absorb chemical residue. Although millions of areas of crops are treated by neonicotinoids either by coating the seed or spraying, products approved for home and garden use are approved to be applied at much higher rates, up to 32 times higher than those approved for agricultural products.
The study found that imadacloprid, clothianidin, dinotefran and thiamethorxam are highly toxic to honeybees, and imadacloprid and clothianidin are highly toxic to bumblebees, and clothianidin and imidacloprid spray are toxic to blue orchard and alfalfa leafcutter bees. As the chemicals breakdown, they are even more toxic to honeybees than the original chemical. Exposures also cause navigation and flying problems, reduced taste sensitivity and slower learning. However, the study was not able to link Colony Collapse Disorder (CCD) between neonicotinoids and honeybees.
Neonic's Impact on Birds and Aquatic Life
But the billions of pounds of pesticides applied yearly across the world affect not just bees, but also butterflies and birds. A recent review evaluating the toxicity risk to birds and aquatic life was released in March, 2013 by the American Bird Conservancy (ABC). “The Impact of the Nation’s Most Widely Used Insecticides on Birds,” is a 100 page report that reviews 200 studies, including industry reports obtained through the Freedom of Information Act. I would like to quote from the entire report, but I will just copy a couple of paragraphs to sum it up.
“The environmental persistence of the neonicotinoids, their propensity for runoff and for groundwater infiltration, and their cumulative and largely irreversible mode of action in invertebrates raise environmental concerns that go well beyond bees.
This report reviews the effects on avian species and concludes that neonicotinoids are lethal to birds as well as to the aquatic systems on which they depend. A single corn kernel coated with a neonicotinoid can kill a songbird. Even a tiny grain of wheat or canola treated with the oldest neonicotinoid, imidacloprid, can poison a bird. As little as 1/10th of a corn seed per day during egg-laying season is all that is needed to affect reproduction with any of the neonicotinoids registered to date. Birds depend heavily on the aquatic systems at the bottom of the food chain. But neonicotinoid contamination levels in surface and groundwater in the US and around the world are strikingly high, already beyond the threshold found to kill many aquatic invertebrates. EPA risk assessments have greatly underestimated this risk, using scientifically unsound, outdated methodology that has more to do with a game of chance than with a rigorous scientific process.”
Further, “It is astonishing that EPA would allow a pesticide to be used in hundreds of products without ever requiring the registrant to develop the tools needed to diagnose poisoned wildlife. It would be relatively simple to create a binding assay for the neural receptor which is affected by this class of insecticides,” said Dr. Mineau. The ABC report calls on EPA to require that registrants of acutely toxic pesticides develop the tools necessary to diagnose poisoned birds and other wildlife.
Suit Filed Against EPA
Subsequently, a suit was file this March 15th against the EPA (Environmental Protection Agency) by a group of California beekeepers and environmental groups, including the Sierra Club (“Suit filed Against EPA over Killing Bees”). The lawsuit against the EPA argues that, via " 'conditional registrations', the regulator rushed the neonicotinoids into the market without sufficient examination and since that time has failed to take account of new information. "Pesticide manufacturers use conditional registrations to rush bee-toxic products to market, with little public oversight," said Paul Towers, at Pesticide Action Network, part of the coalition” (The Guardian, March 22, 2013, “US Government Sued Over Use of Pesticides Linked to Bee Harm”).
On The European Front
At about the same time, the European Food Safety Authority conducted a review of neonicotinoids on bee health. Their report, Existing Scientific Evidence of the Effects of Neonicotinoid Pesticides on Bees was released at the end of 2012. The Executive Summary concluded “Reported sub-lethal impacts on honeybees include various behavioral disturbances, such as reduced homing ability, impaired memory and learning, as well as negative impacts on the ability of worker bees to forage and communicate. Other studies found that the chronic exposure to low doses of neonicotinoids can reduce the breeding success of bees and lead to a neonicotinoid-induced reduction in disease resistance. Thus, a widespread conclusion of different authors is that neonicotinoids can contribute to lethality even at low doses by making bee colonies more vulnerable to other disruptive factors.”
In the wake of this and other reports, three major home improvement retailers in Britain (B&Q, Homebase and Wickes) have taken products containing neonicotinoids off their shelves. In January, 2012, the European commission has proposed a suspension of the use of imidacloprid and clothianidin, made by Bayer, and thiamethoxam, made by Syngenta, on crops that attract bees for two years, if members of the EU agreed in a later meeting in February. The European Commission is also considering banning the use of neonicotinoids by gardeners. The proposed ban was defeated due to the measures of the UK and Germany, the two home base countries of Syngenta and Bayer. However, news from field studies in the UK continue to make the news.
As recently as March 28, 2013, The Guardian, reports: “Syngenta and Bayer, which say the impact of pesticides on bees is unproven and that a ban would deal a blow to the EU economy, proposed a plan to help end the stalemate that they hope will help bees and restore confidence in their products.
Their plan includes the planting of more flowering margins around fields to provide bee habitats as well as monitoring to detect the neonicotinoid pesticides blamed for their decline and more research into the impact of parasites and viruses.”
However, one has doubts about the effectiveness of flowering margins around neonicotinoid exposed crops. As noted in the Xerces study, Are Neonicotinoids Killing Bees?, the adjacent weeds and wildflowers are also contaminated in acreage of chemical exposed crops. Many supporters of the ban are viewing this offer from Bayer and Syngenta as a token gesture, seeking to prevent the proposed EC ban. And if a single grain of neonic coated corn can kill a songbird, what are the effects on humans who consume the many food products made from GMO Roundup-ready/neonic laced corn? I'm afraid to ask if we are ingesting neonics with honey, corn and other exposed crops.
The complications involving the bee and pollinator decline issue are many. Multiple factors seem to be contributing to bee and pollinator decline, the ever increasing fragmentation and disappearance of habitat and a diversity of food source, the devastating effects of the varroa mites and the viruses they carry and the combinations of chemicals pollinators absorb as they buzz from flower to flower. Recently, beekeepers are wondering if excessive harvesting of honey itself contributes to bee decline, substituting sugar water and water mixed with corn syrup to sustain the bees over winter. Some beekeepers report that hives that are left with sufficient honey do not fall victim to varroa mites.
Controversy arises when blaming and attempting removal of a group of chemicals that are credited with controlling damaging insect infestations in a large percentage of the world's food crops. What will or can be used to replace it? Farmers and chemical companies fear huge loss of revenue if such an action is taken. However, on the other hand, there are powerful indicators that neonicotinoids are toxic to bees, birds and aquatic life. How can we balance the loss of revenue from insect damage to the potential loss of natural pollination itself?
Pollinators face difficult times, with the reduction and fragmentation of native feeding and habitat areas, with mites and viruses and with the ever increasing exposure to chemical cocktails. Few people intentionally spray insecticides to kill bees, but what is sprayed severely impacts our pollinators and other critters. Home landscapes devoted to turf and hybrid, sterile, pollen-less plants are pollinator-unfriendly environments. With over 300 insecticide products containing neonicotinoids, chances are neonics are on your shelf. The question is, will they be used this year in your landscape and added to the invisible hurdles and obstacles already faced by pollinators?
Are Neonicotinoides Killing Bees? A Review of Research into the Effects of Neonicotinoide Insecticides and Bees, with Recommendations for Action, by Jennifer Hopwood, Mace Vaughan, Matthew Shepherd, David Biddinger, Eric Mader, Scott Hoffman Black and Celeste Mazzacano, The Xerces Society, 2012.
Existing Scientific Evidence of the Effects of Neonicotinoid Pesticides on Bees, European Food Safety Authority, 2012.
“Impact of the Nation's Most Widely Used Insecticides on Birds, Written by Dr. Pierre Mineau and Cynthia Palmer, American Bird Conservancy, March, 2013.
Mystery Madady Kills More Bees, New York Times, March 28, 2013.
“Pesticide Makers Propose Plan to Help Bees,” The Guardian, March 28, 2013.
“Pesticide Toxicity Profile: Neonicotinoid Pesticides”, by Frederick M. Fishel, professor, Agronomy Department, and director, Pesticide Information Office; Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, Publication #PI-80.
Suit filed Against EPA over Killing Bees, Washington Times, March 23, 2013.
“US Government Sued Over Use of Pesticide Linked to Bee Harm”, The Guardian, March 22, 2013.
Varroa Mites, Publication 2.03, David R. Tarpy and Joshua Summers, Department of Entomology Apicultural Program, North Carolina State University.
Varroa Mite Spread in the US, Adrian M. Wenner and William W. Bushing, Beesource.
“Why Not Just Bring In More Bees”, Texas Bee Watchers, 2/2/2010.
"Why the UK will Fail to Block a EU Ban on Bee-Harming Pesticides”, Damian Carrington's Environmental Blog, The Guardian, April 4, 2013
Angie Hanna, April 9, 2013