• Kevin Elliott

Neonics: Threat to bees but now wider concern

A­s economic analysts around the world debate whether new tariffs on steel and aluminum will spark a global trade war with the United States, few readers are probably aware that a Michigan honey processor in 2013 was the subject of one of the biggest food-related anti-dumping scandals in

the nation.

Dubbed "Project Honeygate" by investigators at the Department of Homeland Security and Immigration and Customs Enforcement (ICE), Groeb Farms, in Onsted, Michigan, and a Texas-based honey processor, were charged in federal court with skirting more than $180 million in antidumping duties related to the illegal import of honey. In 2008, the United States had placed antidumping duties on Chinese honey as a result of exporters selling honey at artificially low prices, some of which was adulterated with unauthorized antibiotics, artificial sweeteners and other contaminants.

Groeb Farms, one of the largest honey processors in the United States at the time, was charged with buying loads of Chinese-origin honey that was either mislabeled as other products, such as sugars or syrups, or shipped through third-party countries, such as Indonesia, Malaysia, Vietnam and Thailand. Prosecutors said the actions helped Groeb Farms avoid paying more than $78.8 million in anti-dumping duties. To avoid trial, the Michigan honey processor agreed to pay a $2 million fine, and subsequently filed for bankruptcy in October of 2013.

Despite the scandal, the flow of honey actually produced by bees in Michigan is among the highest in the country, ranking it as the eighth largest honey-producing state in 2016, according to the United States Department of Agriculture (USDA). Yet, a continuing decline in honeybee populations in Michigan and across the country means continued reliance on imported honey remains necessary to meet consumer demand for the sticky, sweet stuff.

"They need 150 pounds of honey in their hives to survive, and even then they barely make it through the winter. They are supplementing with sugar blocks in the top of the hive," said master honey producer and apiculturist Dennis Holly, who retired from the honey business after nearly four decades in it.

Today, Holly heads up the Oakland Beekeepers' Club, which meets each month at the E.L. Johnson Nature Center in Bloomfield Township, where he is one of the last beekeepers in a long line of honey producers in Oakland County and southeast Michigan.

"A good honey producer gets about 400 pounds out of a hive. The old ones could get 800 pounds," Holly said, "but we can still show people how to get 200 pounds of honey out of amateur hives."

The declines in honey production is one of the effects of declining bee health and population. However, the loss of honeybee population is just one symptom of a much larger issue that results from a specific class of pesticides named neonicotinoids. Across the food chain, scientists are seeing devastating results in other pollinators, bird populations, and everything from earthworms, aquatic invertebrates to birds' eggs.

Beekeepers across the country began reporting widespread losses of honey bees in 2006, according to the Bee Informed Partnership group, which began monitoring bee colony losses that year. Since then, colony losses have been higher than 20 percent each winter, with anything below that mark considered to be "acceptable losses." In Michigan, it is estimated some 177 commercial beekeepers lost 20.5 percent of their bees in the 2016-17 winter season, and 32.6 percent for the entire year. The state's beekeepers lost 58 percent in 2015-16; 54 percent for 2014-15, and 72 percent the previous year.

The annual loss estimates represent only a portion of managed bees. The actual number of managed bee colonies in the state isn't known, as Michigan ended its bee registration program in 1993. In 1992, there were about 2,500 apiaries and more than 100,000 colonies registered in the state, with the majority of those registered being commercial beekeepers. Nor does the inventory account for wild pollinator species in the wild.

Based on the structure of nicotine, neonicotinoids literally means "new nicotine-like insecticides." Often shortened to "neonics," this class of insecticides has come under scrutiny across the globe, with some critics comparing their unintended consequences to that of of the deadly pesticide DDT.

Developed in the 1990s as a less toxic alternative to organophosphate and carbamate insecticides, which pose risks to humans and many animals, neonics are more toxic to invertebrates, like insects. Today, neonics are the most widely used insecticides in the world. In the United States, virtually all corn, a third of soybeans and dozens of other fruits, vegetables and specialty crops utilize neonics.

The most widely used neonic and the first to be approved for use in the United State is imidacloprid, commonly found in Bayer Advance Garden insecticides. Other neonics include acetamiprid, clothiandin, dinotefuran, nitenpyram, thiocloprid and thiamethoxam. Most are effective against sap-feeding pests, as well as grubs, fleas, termites, roaches and other pests.

More than a decade of research indicates neonics have contributed to the demise of honeybees, as well as many other wild bee and pollinator species. The most recent research has found neonicotinoids are present in rivers, lakes and streams throughout the country, and are affecting larger ecosystems, including birds, mammals, fish and other aquatic life.

Water sampling in 2015-2016 of 10 major tributaries to the Great Lakes found neonicotinoids in 74 percent of monthly samples over the course of a year, with River Rouge in Detroit accounting for the highest maximum concentrations of all locations tested, according to a report published in October of 2017 by researchers with the United States Geological Survey (USGS).

The most frequently detected insecticide was imidacloprid, which was found in 53 percent of samples, including 92 percent of samples taken from the Rouge River. Concentrations of imidacloprid in Rouge River were found throughout the year, but were highest in August. Detections of clothianidin was found in 44 percent of tributaries, including in Rouge River during some spring months.

"We were most surprised that at some sites we were finding these insecticides throughout the year. Not at all the sites, but at some," said Michelle Hladik, a research chemist with the USGS at the California Water Science Center in Sacramento, who co-authored the study. "People tend to think of insecticide use in the summer, so it's not surprising you would find those more frequently. But we were more surprised that we were finding them at some sites in the winter, which gives the potential for more of a chronic (longterm) exposure scenario."

The study was the first of its kind to look specifically for neonics in Michigan, and the latest of several conducted by the USGS on the issue. The study confirms the widespread use of neonicotinoids beyond agriculture, and illustrates the nation's dependency on chemicals for maintaining rural farmlands, suburban lawns and gardens, and urban landscapes. Scientists are now trying to determine the ramifications of that dependency and how it may be impacting food production, ecological systems, animal health and human well-being.

Sally Petrella with Friends of the Rouge said the group was already aware that other insecticides have been found in surface waters in southeast Michigan, but the new study results weren't expected.

"We were surprised by the findings," she said. "A surprising amount of pyrethroids have been found previously, which is a concern because we have multiple stressors."

Stressors are contaminants or pathogens that can negatively impact the ecology of natural habitats. As the volunteer monitoring program manager for Friends of the Rouge, Petrella is involved first hand in looking for sensitive aquatic macroinvertebrates that are sensitive to stressors, such as mayflies, stoneflies and caddisflies. A loss of such species is an indicator that there is a problem with water quality.

"The Rouge has vastly improved from what it once was. We are seeing dissolved oxygen improve and more fish, but overall they are in the fair range for macro invertebrates, and some are poor. They are still pretty impacted," she said.

While neonics are particularly harmful to mayflies and some other macroinvertebrates, Petrella said it's hard to connect the low levels of them with a specific insecticide because there are multiple stressors at play.

Still, one may safely assume that suburban landscape practices are impacting indicator species based on monitoring locations and known sources of other contaminants, such as sewage overflows.

"We have seen increases (in indicator species) in the middle branch and Johnson Creek, and declines in the upper branch, which starts in West Bloomfield and goes through Farmington. That one we have seen declines, as well as the upper branch part of the main, which starts in Rochester Hills and includes Bloomfield and Birmingham," Petrella said. "Our industrial pollution isn't increasing, and most of that is much further downstream. The majority of our pollution is actually stormwater pollution, not industrial. Farther downstream there are about 40 uncontrolled combined sewer overflows in the lower. There aren't that many overflows in the main. Most of those have been controlled."

A 2013 report published in the Journal of Applied Ecology by Biological Environmental Scientist Dave Goulson, with the University of Sussex and University of Stirling in the United Kingdom, gave a summary overview of the environmental risks posed by neonicotinoid insecticides. The report highlighted studies that showed neonics persist and accumulate in soils. And, because they are water soluble, they are prone to leaching into waterways. Being systemic, they are found in nectar and pollen of all treated crops.

"Reported levels in soils, waterways, field margin plants and floral resources overlap substantially with concentrations that are sufficient to control pests in crops, and commonly exceed (the concentration which kills 50 percent) for beneficial organisms," the report summarized. "Concentrations in nectar and pollen in crops are sufficient to impact substantially on colony reproduction of bumblebees."

The report also highlighted how certain applications of neonics may be lethal for some birds and mammals. While more recent research has confirmed and expanded on neonicotinoids' impact on birds, mammals, fish and other species, information in 2013 was still sufficient to lead the European Union's governing body to restrict neonic use.

In 2013, the European Commission placed a moratorium on some uses of three neonicotinoid insecticides, which by no coincidence is now undergoing new risk assessments by the Environmental Protection Agency (EPA) in the United States.

The European Union's restrictions were based on risk assessments conducted by the European Food Safety Authority (EFSA) in 2012 that found the compounds threaten bee species vital for pollinating crops. The EFSA in February of 2018 released another assessment of the three insecticides, which concluded they pose a high risk to wild bees and honeybees. The EU may now move to ban all uses of the insecticides.

The EPA, which registers and reassesses pesticides available for use in the United States, requires pesticides to be re-registered on a 15-year cycle. However, the EPA in 2009 opened registration review dockets on five neonic insecticides, including imidacloprid, clothianidin, thiamethoxam, dinotefuran, and acetamiprid. Preliminary assessments on risks to pollinators and humans have been completed for all of the insecticides, with preliminary aquatic ecological assessments and non-pollinator ecological assessments completed for imidacloprid. Full reviews for all are planned for sometime in 2018, according to the EPA.

Meanwhile, federal legislation in the United States has been introduced in Congress several times in the past five years, with Democratic attempts to restrict the use of the insecticides dying in a House subcommittee each time.

"This bill would protect the health of honeybees and other critical pollinators and suspend the use of bee-toxic neonics. It also requires the Environmental Protection Agency to complete a thorough assessment and ensure that any use of these insecticides does not cause unreasonable and adverse effects on pollinators," Congressman Earl Blumeanauer (D-OR), said in February when introducing the latest version of the bill that was originally introduced by former Michigan Congressman John Conyers (D-Detroit). "The health of our food system depends on the health of our pollinators, and the EPA has the responsibility to get to the bottom of this issue. I urge my colleagues to join me and pass this legislation so that we can save our pollinators. The future of our food depends on it."

Globally, commercial pollinator services are valued at over $125 billion, accounting for about $24 billion in the United States, with honeybees specifically providing at least $15 billion to the nation's economy. Native pollinators, such as bumblebees, squash bees and mason bees, contribute more than $3 billion to the US economy. The United States Department of Agriculture (USDA) has said losses in honeybee colonies, which provide the majority of commercial pollinator services, are too high to confidently ensure the United States will be able to meet the pollination demands for agricultural crops.

With commercial honeybee pollination services needed for at least a third of all crops grown in Michigan, honeybees amount to about $1 billion in value in the state. In addition to fruits, vegetables, corn and other crops, pollinators support the beef and dairy industry in Michigan and other states through the pollination of alfalfa and clover. Managed pollinators in Michigan typically ship their bees out of state during the winter months to other states, including California where up to 70 percent of the nation's managed honeybees are shipped each winter to pollinate almond trees.

Outside of managed pollinators, more than 40 wild pollinator species are federally listed as threatened or endangered species. In July 2014, the U.S. Fish and Wildlife Services announced plans to phase out neonicotinoid insecticides at all national wildlife refuges.

Oakland Beekeepers' Club's Holly, who previously served as vice president for the Southeastern Michigan Beekeepers' Association and district representative for the Michigan Beekeepers' Association, said most honey producers don't ship their bees out of state during the winter for commercial pollination services. Instead, he said, some will move them to warmer climates, with many smaller operations and amateur keepers keeping their hives in state throughout the year. Still, some provide pollinator services on a more local level.

"In my opinion, there aren't really any natural pollinators left in Oakland County. There are some, but not enough," Holly said. "Farmers here are begging for bees. When you lose them, you have to replace them."

Beekeepers who keep their hives in Michigan may be especially hard hit this year, as Holly said many have reported losing up to 80 percent or more of their colonies. The losses, he said, are due to a combination of issues, including the presence of neonicotinoids.

"There was a phenomenon this year that happens every seven or eight years," Holly said. "This year, we had temperatures at 28 below zero for 10 days – that's not common. We haven't exposed bees for 10 days like that for quite a while. If you do that, the hive has to be perfect or they won't make it. It killed most of the bees from here to the UP."

In addition to cold temperatures, Holly said many beekeepers had problems with mites infesting their colonies this winter. If infestations aren't treated properly by mid-August, he said the mites will burrow into the bees, causing them to stress and die. Exposure to neonicotinoids, Holly said, is another added stress, which he believes has led to decreases in population.

"Neonicotinoids are a real problem. That affects the bees' memory and the queen and everything, but it's not the only pesticide. Even Roundup effects bees. All these pesticides effect bees, which are already in trouble because of the mites," Holly said. "But I think something new has popped up, and we have an issue in Michigan that is going to come up soon. They are killing the bees, and they need to remove (neonicotinoids) from the food chain, in my opinion."

Because neonics are highly water soluble, they can be applied to the soil and taken up by plants, a process known as soil drenching. They can also be injected into plants and trees, and sprayed on foliage. In farming, neonics are commonly used as a seed coating applied before crops are planted and ensures that all parts of the plant are treated. They are also used in granular formulations.

One of the most common applications of neonics is in seed treatment, a process in which seeds are coated with neonicotinoids prior to planting. The result is a plant that contains neonics, from its roots to its pollen, during its entire life cycle.

Whatever the method of application, neonics act as a systemic insecticide, meaning once taken up by the roots or other part of the plant, it becomes present in all parts, from the roots and stem to the leaves, flowers, nectar and pollen, meaning multiple routes of exposure are ever-present.

Thomas Wood, a postdoctoral research associate with the Department of Entomology at Michigan State University, said the potential for pollinators to be exposed to harmful effects doesn't depend only on the toxicity of the pesticide.

"If you were to treat canola for flea beetles by spraying a pyrethroid on its surface, it is more directly toxic the bee, but if you sprayed outside of foraging hours, it is less likely to come into contact with the bee, because it's not systemic and has a low solubility," he said.

Wood said the use of neonicotinoids in seed dressings is commonplace in some crop production, including corn and specialty crops, such as garlic, as well as all pickling cucumbers in Michigan.

"It's a standard, and it's now difficult to get untreated seeds for some crops," he said. "The increase in seed dressing usage exploded from about the mid 2000's to 2005 and onward."

While neonics are systemic, studies show that only about five percent of the insecticide's active ingredient is taken up by the plant, with most being dispersed to the wider environment. Neonics used as seed dressings provide more additional routes of exposure to pollinators, as well as other non-target species

Birds that graze in farm fields may eat seeds coated with neonics, which depending on the species, size of the bird and amount of seeds they consume, can be harmful to animals.

One study found that a grey partridge weighing 390 grams would need to eat about five treated corn seeds, six sugar beet seeds or about 32 canola seeds to receive a lethal dose. The EPA's own assessments have confirmed similar findings in other bird species, and estimates about one percent of planted seeds are accessible to foraging species. As grey partridges typically consume about 25 grams of seeds per day, the study found "there is a clear potential for ingestion of neonicotinoids by granivorous animals, specifically birds and mammals."

In February of 2017, Wood and Goulson compiled an updated report of Goulson's summarized findings from 2013. The report, "The Environmental Risks of neonicotinoids pesticides: a review of the evidence post 2013," compiled new findings that included the most recent understanding of the pesticides' impact on mammals, birds and aquatic species.

The report noted that in addition to systemic exposures from plant, nectar and pollen, seed coatings may result in two additional exposures. During the planting season, neonicotinoids present on treated seeds may rub off and turn into dust, which is then emitted into the air. As a result, Neonics released in dust abraded by seed drilling machines were implicated in mass poisoning of honeybees in some locations.

Researchers found that honeybee queens exposed to small doses of the neonicotinoid insecticide imidacloprid through shared food had reduced egg laying and locomotor activity, and worker bees had modified foraging and hygienic behaviors, according to the Michigan Department of Agriculture. While the effects may not immediately kill the bees, it may cause the colony to dwindle over time. Sublethal exposures may also make the colony more susceptible to other threats, like pathogens and pests.

The sublethal effects from dust generated during harvesting is one possible factor in decreased honeybee populations in Michigan, according to Holly.

"We have a problem with soybeans that I think may have killed some bees when they harvest the crop," Holly said. "It's a systemic pesticide, so it stays in the plant until they grind up the beans. This season, they were late in doing that. We are still trying to see if they were allowed to spray when bees were foraging, or if there was something else."

Additional studies have found that molluscan herbivores, such as slugs, may be effected or die from exposure to feeding on neonic-treated plants. Further, one study showed that 61.5 percent of ground beetles, an important predator of slugs, showed signs of neonicotinoid impairment, with seven out of 16 having died after feeding on the slugs.

Earthworms, which have similar neural pathways to insects, are highly likely to be exposed to neonics from direct contact with soil, according to recent studies. Those studies found presence of neonics in earthworms from soil ingestion in fields that hadn't been treated for over a year.

Studies have also found neonics threaten blue crabs and other aquatic invertebrates, such as freshwater snails and water fleas. Increased deaths of blue crab is a large concern in the Chesapeake Bay region where they support commercial and recreational fishing, as well as the region's ecosystem.

In terms of human health, preliminary risk assessments released by the EPA on imidacloprid determined exposure from treated plants and drinking water isn't a cause for concern. Additionally, the EPA's assessment found that exposure through medicated pet treatments of imidacloprid is not harmful to adults, but is a cause for concern among children younger than two-years-old, which may be exposed through the skin by petting treated animals, and by oral exposure, by putting their hands in their mouths after petting treated animals.