Everyone from scientists to environmentalists to beekeepers are clamoring for more research on the effects of neonicotinoids on honey bees.
How do neonics affect queen bees?
Newly published research led by Geoffrey Williams of the Institute of Bee Health, Vetsuisse Faculty, University of Bern, Switzerland, indicates that neonics severely affect queen bees.
They published the article, Neonicotinoid Pesticides Severely Affect Honey Bee Queens, on Oct. 13 in the "Scientific Reports" section of Nature. The abstract:
"Queen health is crucial to colony survival of social bees. Recently, queen failure has been proposed to be a major driver of managed honey bee colony losses, yet few data exist concerning effects of environmental stressors on queens. Here we demonstrate for the first time that exposure to field-realistic concentrations of neonicotinoid pesticides during development can severely affect queens of western honey bees (Apis mellifera). In pesticide-exposed queens, reproductive anatomy (ovaries) and physiology (spermathecal-stored sperm quality and quantity), rather than flight behaviour, were compromised and likely corresponded to reduced queen success (alive and producing worker offspring). This study highlights the detriments of neonicotinoids to queens of environmentally and economically important social bees, and further strengthens the need for stringent risk assessments to safeguard biodiversity and ecosystem services that are vulnerable to these substances."
Williams and his research team correctly noted that "a plethora of literature has demonstrated lethal and sub-lethal effects of neonicotinoid pesticides on social bees in the field and laboratory" but that much of that research was done on worker bees.
"In this study, we hypothesised that exposure to field-realistic concentrations of neonicotinoid pesticides would significantly reduce honey bee queen performance due to possible changes in behaviour, and reproductive anatomy and physiology," they wrote. "To test this, we exposed developing honey bee queens to environmentally-relevant concentrations of the common neonicotinoid pesticides thiamethoxam and clothianidin. Both pesticides are widely applied in global agro-ecosystems and are accessible to pollinators such as social bees, but are currently subjected to two years of restricted use in the European Union because of concerns over their safety. Upon eclosion, queens were allowed to sexually mature. Flight behaviour was observed daily for 14 days, whereas production of worker offspring was observed weekly for 4 weeks. Surviving queens were sacrificed to examine their reproductive systems."
They called for more research on the effects of the pesticides on queen bee reproduction:
"Current regulatory requirements for evaluating safety of pesticides to bees fail to directly address effects on reproduction. This is troubling given the key importance of queens to colony survival and their frailty in adjusting to environmental conditions. Our findings highlight the apparent vulnerability of queen anatomy and physiology to common neonicotinoid pesticides, and demonstrate the need for future studies to identify appropriate measures of queen stress response, including vitellogenin expression. They additionally highlight the general lack of knowledge concerning both lethal and sub-lethal effects of these substances on queen bees, and the importance of proper evaluation of pesticide safety to insect reproduction, particularly for environmentally and economically important social bee species." Read the full report.
Meanwhile, the University of California, Davis, just held a sold-out conference on neonics. The speakers' presentations (slide shows) are posted on the California Center for Urban Horticulture's website.
Everyone agrees on this: more research is needed.
Bee health is a challenge, and this hot topic tied in with ESA President Frank Zalom's theme "Grand Challenges Beyond the Horizons." Zalom, who just completed his presidential term and is now serving as past president, is a distinguished professor of entomology at the University of California, Davis, and an integrated pest management specialist.
Debate topics are always lively and this one was no exception. The teams are given eight months to practice for the 45-minute debate. The end result: their work is published in the ESA journal, American Entomologist.
From all accounts, it was a fantastic debate, with both sides making key points. The UC Davis team, captained by Mohammad-Amir Aghaee, successfully argued that a ban on the insecticides in agriculture “will not improve pollinator health or restore populations, based on current science. Neonicotinoids are important for control of many significant agricultural and veterinary pests. Part of the solution is to develop better regulations that will protect the health of pollinators and retain the use of an important IPM tool.”
UC Davis won the debate, and then went on to win the overall ESA student debate championship for the second consecutive year.
“Neonicotinoids are important for control of many significant agricultural and veterinary pests,” Aghaee said at the onset. “Part of the solution is to develop better regulations that will protect the health of pollinators and retain the use of an important IPM (integrated pest management) tool.” The team also argued successfully that neonicotinoids (also known as neonics) are not all “created equal.” The insecticide, chemically similar to nicotine, is implicated in the mass die-off of pollinators. The European Union recently adopted a proposal to restrict the use of three pesticides belonging to the nenicotinoid family (clothianidin, imidacloprid and thiametoxam) for a period of two years. In addition, the U.S. Fish and Wildlife Service announced that by January 2016, it will ban the use of seeds treated with neonicotinoid pesticides and the use of crops improved through biotechnology throughout the 150 million acres managed by the National Wildlife Refuge System.
In addition to Aghaee, the UC Davis team included graduate students Margaret "Rei" Scampavia, Ralph Washington Jr., and Daniel Klittich. Michael Parrella, professor and chair of the UC Davis Department of Entomology and Nematology, served as their advisor. The Auburn team, captained by Olufemi Ajayi, included Adekunle Adesanya, Julian Golec, Matt Burrows, Scott Clem and alternate Zi Ye. Associate professor David Held served as their advisor.
The protocol included a seven-minute statement by each team; cross-examinations; rebuttals; and questions from the judges and audience.
The UC Davis team cited three main points:
- Pesticides are IMPORTANT tools used in modern agriculture
- Neonicotinoids were registered as reduced risk pesticide to replace the organophosphates, carbamates, and pyrethroids
- Banning neonicotinoids would increase of use of pesticides that have known non-target effects
The UC Davis entomologists agreed that acute and chronic studies "have shown that neonics are toxic to honey bees and bumble bees (Blacquiere et al. 2012)" but argued that “all neonics are not created equal (Brown et al. 2014)." They cited “inconsistent results with field-realistic doses (Cresswell et al. 2012)" and noted that “many other factors have been documented as contributing to pollinator decline (Epstein et al. 2012).”
It's not just insecticides that are killing bees, the UC Davis team pointed out. They listed the varroa mite (Varroa destructor), vectored pathogens, and the acaricides, antibiotics and fungicides that are directly added to the colony. They also mentioned American foulbrood and Nosema bombi; inadequate honey bee nutrition; insufficient food substitute; habitat fragmentation; land-use changes; and the increasing demand for pollination changes.
The UC Davis entomologists recommended that regulatory agencies need more thorough registration guidelines that incorporate bee toxicity data for all pesticides (Hopwood et al. 2012). This would encompass chronic toxicity, sublethal effects and synergistic effects. Another recommendation: mandate better management practices that follow IPM principles that protect bees on crops (Epstein et al. 2012). This would include banning certain application strategies, using less toxic neonicotinoids, and encompass the essential education and communication.
The UC Davis team summarized its argument with “There is NO definitive scientific evidence that neonicotinoids are the primary cause of pollinator declines. Neonicotinoids are important reduced risk pesticides for management of some of our most damaging pests. Neonicotinoids should be better regulated, not banned." They concluded: “Given the current state of knowledge, banning neonicotinoids is a premature and disproportionate response to a complex issue. This requires holistic scientific inquiry and interpretation, and cooperation among stakeholders. Any changes must be based on science rather than opinion, current trends, or fear.”
The Auburn team argued that neonicotinoids are causing the death of bees essential for pollinating our food crops, and that the use of neonicotinoids should end. They outlined six key points:
- Critical time for pollinators in the United States
- Lethal and sub-lethal effects
- Prevalence and exposure
- Effects on other pollinators
- Food Quality and Protection Act (FQPA) as a precedent
Expanding on the fact that this is “a critical time for pollinators in the United States,” the Auburn team pointed out that honey bees pollinate $15-20 billion worth of crops in the U.S., and $200 billion worldwide; that approximately $3 billion worth of crop pollination services are provided by native bees; and that CCD likely has many contributing factors but many of those are enhanced by neonicotinoids. They said that the honey bee population is declining. In 1947, the United States had 6 million bee colonies and today, it's down to 2.5 million.
The Auburn team keyed in on lethal and sublethal effects of neonics: synergistic interactions with other pesticides, including DMI (demethylation inhibitor) fungicides; increased susceptibility to pathogens (Nosema spp.); decrease in foraging success; decrease in overwintering queen survival; learning impairment consequences; and reproductive inhibition. They also called attention to prevalence and exposure to neonicotinoids. They discussed the neonicotinoid residues found on bee-pollinated crops and plants by various means of exposure: seed coating; foliar spray, soil drench, trunk injections; length of residue (soil vs. foliage and length of bee exposure); and single exposures resulting in season-long impacts. They also said the multiple means of exposure due to application can lead to multiple routes of exposure within bees: via pollen, nectar, guttation fluid and extrafloral nectaries.
In their concluding statement, the Auburn team said that current tools for risk assessment may not be adequate; and that limiting neonicotinoid use will not harm agriculture--"it will open the door for more sustainable agriculture and new insecticides." They emphasized that we must save our pollinators, especially in the United States. "The United States is a special case--globally there is an increase in bee colonies; however, the United States is at a critical point at which bee pollination services are being threatened irreversibly."
One of the several swaying arguments that led to UC Davis winning the debate was that not all neonics are created equal, and thus, they should not all be lumped together as "an equal" and all be banned.
The UC Davis team received a $500 cash award, a plaque and a perpetual trophy engraved with UC Davis. ESA president Frank Zalom presented the awards.
Next year's ESA meeting takes place Nov. 15-18 in Minneapolis. Its theme, chosen by ESA President Phil Mulder, professor and head of the Department of Entomology and Plant Pathology at Oklahoma State University, is "Synergy in Science: Partnering for Solutions." He says that the theme "represents a collaborative effort with the other societies, but genuinely keeps us focused on our three strategic principles; 1) our social responsibility to develop ALL members, 2) exploring global partnerships and relationships within our science, and 3) expanding our influence around the world to maximize the impact that entomology has on improving the human condition and our knowledge of the world around us."
Mussen, who retired in June after 38 years of service, says "Neonics are only one of the classes of pesticide residues that we frequently find in analyses of adult bees, beeswax and stored pollens. We encounter CCD in colonies in which no neonicotinoid residues can be found, and we find colonies surviving year after year with measurable residues of neonicotinoids in the hives. Obviously, neonicotinoids do not appear to be ''the primary' cause of CCD."
Enter Matan Shelomi, a young, thoughtful and articulate entomologist who frequently answers questions on Quora. Huffington Post picked up his comments on Quora--What's the deal with the Bees?--about our bee-leagured bees. (Quora, launched by Harvard students, is a site where you can ask questions and get answers, and Shelomi answers plenty of them and quite well. A couple of years ago he tied for a first-place Shorty Award, the social media-equivalent of an Oscar.)
But first, more about Matan Shelomi. He's a Harvard graduate who received his doctorate in entomology this year from UC Davis, studying with major professor Lynn Kimsey, director of the Bohart Museum of Entomology and UC Davis professor of entomology. He is presently a postdoctoral researcher at the c in Jena, Germany. It's a two-year position funded by a National Science Foundation Postdoctoral Research Fellowship in Biology. "My work is a continuation and expansion of my doctoral research at Davis: I am studying the endogenous cellulases and pectinases of the stick insects (Phasmatodea). By taking insect genes for these enzymes and expressing them in insect cell lines, we can quantitatively test the function of these genes and try to determine what role they play in the living insect and how they evolved."
Shelomi keyed in on those questions and more after hearing "a great talk by the venerable Dr. May Berenbaum, a wonderful entomologist and effectively the scientific spokesperson about Colony Collapse Disorder (CCD), the technical term for the phenomenon of vanishing bees. So I present here for you the current state of knowledge on CCD: its history, its causes, and what we can do so stop it." Berenbaum, professor and head of the Department of Entomology at the University of Illinois, is in line to be president of the 7000-member Entomological Society of America.
"CCD does not have one cause," Shelomi emphasized. "There is no one chemical to ban or one company to censure or one critter to eradicate. Instead, CCD is the product of several factors whose whole is deadlier than the sum of its parts: a perfect storm of biological and cultural issues that are too much for the already genetically weak honeybees to handle. However, honeybees and bees themselves are not going extinct anytime soon."
Shelomi noted that honey bees are not native to America. "European honey bees were imported to the United States a few centuries ago, where they adapted well to the local plants. Without bees, certain crops (most notably almonds) could not be produced."
"Beekeeping practice also changed remarkably in the past century. Beekeepers realized the market for pollination, and began to transport their hives around the country following the crop seasons, first by rail and then by truck. The demand for bees was higher than the supply, however. In the USA, the Almond Board successfully lobbied Congress to allow the importation of bees from Australia, which was illegal at the time to prevent the importation of foreign bee diseases. As the world changed and more wild land was converted to agricultural land, then agricultural land to urban land, the amount of food for bees decreased. The natural diet of bees is honey and bee bread, which is fermented pollen. Fewer wild flowers meant less natural food for the bees, requiring other sources. To keep their bees alive, beekeepers started feeding sugar solutions to bees, including high fructose corn syrup."
Then came CCD. "In 2006, many beekeepers across the USA began to report high losses of bees. Not deaths, but losses: the worker bees would just vanish, leaving the queen and brood behind. This is very unusual: honey bees don't leave their home and family behind like that. With the workers gone, the hive soon followed. It soon became evident that this was a nationwide problem, and one that eventually spread to Europe too. Because of the immense importance of bees in agriculture, groups from all over the US worked together, and solving the case of Colony Collapse Disorder became a priority."
In his Quora answer, Shelomi discusses research findings and new research underway. "Here is perhaps the biggest finding from the honey bee genome research: Honey bees are naturally lacking in immunity and detoxification genes. Compared to other insects, bees lack many natural defenses! Namely, they have fewer glutathione-S-transferases, carboxylesterases, and cytochrome P450's, which are the proteins animals (including humans) use to break down toxins. Bees eat pollen and honey, which are hardly toxic. In the millions of years of their evolution, they have lost many of these genes for defense, which means all honey bees are naturally weakened against diseases and chemicals."
So, bottom line? "I'll give you a hint: it's not one thing," Shelomi wrote. "No matter what you are reading, if you find any source that names only one cause for CCD -- a single chemical, a single pesticide, a single company, a single country-- then you should stop trusting that source. On anything. Ever. Science doesn't work that way, and, no, there is no one cause for CCD, nor is there one solution. Anyone who says otherwise is either pushing a certain viewpoint on you or hasn't done there research. Here's the big reveal."
When you get a chance, read his entire essay and take note of his summary: "...CCD happens because bees have a naturally poor immunity to disease and to chemicals, both of which they are exposed to at higher rates and often together, and that immunity is made worse due to poor diet and stressful conditions. There is no one cause, nor is there one solution."
What we can do to help the bees? "Two things. Plant flowers that bees like in your garden, if you have one. Help undo the damage of habitat loss by giving bees a source of food on your property. The second is to support your local beekeeper by buying local honey, if appropriate. Go to a farmers' market or otherwise get the honey from someone raising bees nearby. It will help them out, and you can ensure you are getting real honey and not laundered stuff."
Shelomi is spot on when he says that "the best thing you can do is stay informed... and that doesn't mean finding one source of information and trusting them blindly. To stay informed means you will always need new information, and are never satisfied. It means always doubting every new news story that pops up, especially if it seems too good to be true or claims to 'finally' answer a question. It means don't confuse a conspiracy theory website or an anti-agrotech blog, or even a news report, for actual scientific data. Nor should you trust one scientific paper above all others, especially if it's a single study and not a meta-analysis. Science is ever changing: look at how much our knowledge of bees changed since 2006, how many theories were tested, championed, then abandoned as new evidence came up. Even all I've posted here may one day change (though it's pretty well accepted so far). The story of the honey bees isn't over yet... but I promise it will not have a grand finale or a single climax, but rather will be complex and full of intertwining characters, and the ending, though perhaps not as spectacular, will be much more satisfying."
Excellent advice. Stay aware. Stay informed. Stay tuned.
The neonicotinoid pesticides are creating quite a buzz in the bee world.
Research published this week in the Science journal zeroed in on the effects of the neonics on honey bees and bumble bees.
Science writer Eric Stokstad, in his news analysis headlined "The Field Research on Bees Raises Concern About Low-Dose Pesticides," indicated that, bottom line, more research on pesticide testing and regulation is needed.
"Five years ago, bees made headlines when a mysterious condition called colony collapse disorder decimated honey bee colonies in parts of the United States," Stokstad wrote. "Now bees are poised to be in the news again, this time because of evidence that systemic insecticides, a common way to protect crops, indirectly harm these important pollinators. Two field studies reported online this week in Science document problems. In bumble bees, exposure to one such chemical leads to a dramatic loss of queens and could help explain the insects' decline. In honey bees, another insecticide interferes with the foragers' ability to find their way back to the hive. Researchers say these findings are cause for concern and will increase pressure to improve pesticide testing and regulation."
Stokstad was referring to these two research articles published in Science:
1. Neonicotinoid Pesticide Reduces Bumble Bee Colony Growth and Queen Production
2. A Common Pesticide Decreases Foraging Success and Survival in Honey Bees
Meanwhile, Extension apiculturist Eric Mussen of the UC Davis Department of Entomology is fielding calls about the research.
On Wednesday, Mussen talked to science writer Eryn Brown of the Los Angeles Times.
Here's her quote from her news story:
“There are a whole lot of things that stress the honeybees,” said Eric Mussen, a honeybee specialist at the University of California, Davis. “You can’t point your finger at one thing and say, ‘That is the problem.’ ”
Mussen cautioned against singling out neonicotinoids when other pesticides could have similar effects on bees. Besides, he said, many insects have built up immunity to neonicotinoids, so farmers are likely to switch to different pesticides anyway.
As Mussen has been saying all along, the declining bee population is due to a number of factors: pests, pesticides, parasites, diseases, malnutrition and stress.
So, there's no silver bullet--no major culprit--that's causing the declining bee population. It's a multitude of factors. Scientists continue to investigate them all.