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.
Honey bee guru Eric Mussen talks a lot about the declining honey bee population.
After all, he's served as the Extension apiculturist with the UC Davis Department of Entomology since 1976.
Over the last several weeks, however, he's been fielding scores of phone calls from the news media and delivering presentations to various groups. Last Tuesday, he addressed the University of California Cooperative Extension (UCCE) Pollinator Workshop in Woodland.
This morning he discussed bee health with a news team from KGO Radio, San Francisco.
Everyone wants to know how the bees are. Just as we greet folks daily with "How are you?" Mussen hears a daily "How are the bees?"
So, when the KGO news team telephoned him at 7 this morning, Mussen knew the topic: Bee health.
"Are we making any progress to finding out what causes colony collapse disorder (CCD)?" Mussen was asked.
CCD is a mysterious malady characterized by adult bees abandoning the hive.
"I think things are a little bit better...but we don’t know what causes CCD," Mussen told KGO. "And what the beekeepers have found, however, is that malnutrition seems to be pretty important. One beekeeper told me that $45 invested in food for the bees--artificial food, you know because we can’t really substitute for pollen--made his bees considerably better.
"And the second thing they’re finding is that it seems to go in a two-year cycle. The young colonies don’t seem to have that so much of a problem but the second year ones do, so now what they’re doing is breaking those second-year colonies down into smaller ones starting them over again and keeping them young and that helps too."
Mussen believes that CCD is linked to multiple factors, including parasites, pesticides, diseases, malnutrition and stress. The end result: a compromised or weakened immune system.
Some folks finger a class of pesticides, the nicotine-based neonicotinoids, as "the cause" of CCD. Not "the cause," says Mussen.
When the KGO news team quizzed him about this systematic pesticide--how France banned it and then "saw a return of the bees within a year"--Mussen responded: "Well, by the same token, there were some researchers in France that took sugar syrup and laced it with sublethal doses of the particular chemical you’re talking about and fed it to the bees all year and those bees were fine that year, through the winter and then into the next spring."
At Tuesday's meeting in Woodland, Mussen cautioned that adjuvants (materials added by a pesticide applicator to a product "to make it work better") may be causing brood and queen-bee rearing problems. "Adjuvants--especially the organosilicone 'superspreaders'--seem to make non-toxic fungicides toxic to honey bee brood," Mussen said. 'These superspreaders can penetrate the waxy cuticle on Eucalyptus leaves. And the No. 1 bee protection is their waxy cuticle."
Although the U.S. Environmental Protection Agency (EPA) and the California Department of Pesticide Regulation demand acute toxicity tests before a pesticide is marketed, still there are concerns, Mussen told the Woodland crowd. For one, the contact/ingestion studies last only 48 hours and "that's too short of a time period" to see what happens to the bees. "Sublethal effects are not required, chronic exposure to sublethal doses is not required, and synergism is not studied," he said.
Look for him to expand on the issue in his next from the UC Apiaries newsletter, available free on the UC Davis Department of Entomology website.
With the opening of baseball season, it's "peanuts, popcorn and Cracker Jacks!"
But to beekeepers, it's peanuts.
Or rather, peanut-like shells.
Immature queen bees grow to maturity in cells that resemble peanut shells.
When UC Davis bee breeder-geneticist Susan Cobey, manager of the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis, led a recent queen-bee rearing class on a tour of commercial queen bee producers, one of the stops was at C. F. Koehnen & Sons, Inc., Glenn, Calif.
The Koehnens, in the bee business since 1907, are the largest producers of honey bees and queen bees in California. They maintain more than 15,000 colonies. The Cobey class marveled at the operation.
A beekeeper held a frame up to the sky as worker bees cleaned out the vacated queen bee cells.
Not your basic goober peas!