The honey bee guru continues to answer a range of questions. The latest concerns the effect of marijuana growing sites on honey bees.
We thought we'd share his answer, which deals with honey bees, pollinators, Cannabis, pesticides, and what could happen to beekeepers who stumble upon a pot farm.
The question: "What is the effect, good or bad, that marijuana plants and marijuana grow sites have on the honey bee? From what I understand, these grow sites are using chemicals to control pests year round. In some cases, I hear that marijuana growers are importing chemicals from Mexico that are stronger and work better to control pest."
Mussen answered the question succinctly and openly.
"As you might guess, since marijuana is still considered an illegal plant to grow by the federal government," he replied, "it is no surprise that there are no pesticides registered for use on the 'crop.' Some states are trying hard to build a list of acceptable products, but here is the problem. So far we have registered products based on contact and oral toxicities to mammals. We have only run inhalation toxicities on a few very potent and stinky products (fumigants). You can get up to 10X the dose of a chemical, from the same amount of plant mass, if you smoke it versus eating it.
"There are quite a number of websites dedicated to pot growing. When pest control becomes the topic, most sites suggest mechanical methods or use of products allowed in organic agriculture. However, those organic pesticides have not been checked for inhalation effects, either."
"Thus, practically any pesticide that is used will be illegal. Given that, growers are apt to determine which materials work best on the pest at hand on other crops, acquire those materials, and use them. The regulators know this, and in states where marijuana currently is legal, the states are testing some of the products on the shelves to see what pesticides are in them. The samples have been found to be pretty clean, for the most part."
Mussen acknowledged that blooming hemp plants are attractive to many pollinators. "I have no idea what the pollen and nectar might do to them when the bees consume it. We can provide a pretty good idea of what will happen when pesticide products used on other crops are applied to the bloom (at agricultural rates), but since nothing is registered, there is no way of guessing what might be used. For the standard fee of just under $400, we can send a sample of the bees or pollen to the USDA AMS pesticide residue detection lab in Gastonia, N.C., and they can tell us the residues. Butthat doesn't help us much in terms of regulatory assistance.
"Pot growers probably won't care if they repel or kill visiting bees," Mussen speculated. "Pollinated blossoms become senescent too quickly, and do not produce the maximum amount of important resins if they are pollinated early in their cycle."
"Up to this time, I have not heard of beekeepers reporting damage from pesticides applied to marijuana, but it is likely to happen before long. Beekeepers are more worried about being shot if they accidentally get too close to a pot farm."
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.
Based in the UC Davis Department of Entomology and Nematology, Mussen completed 38 years of service last June and is nationally and internationally known as "the honey bee guru."
"Most of us take pollinators for granted. That's a key reason why Gov. Jerry Brown has joined other governors throughout the country to celebrate June 15-21 as National Pollinator Week. It's a time to appreciate what bees, butterflies, beetles, bats and other pollinators do. Honey bees and native bees are especially important for the pollination of our agricultural crops. Without them, we'd be pretty much confined to a boring, unappealing and non-nutritious diet of wheat and rice."
"Many beekeepers can't keep their colonies alive, no thanks to pesticides, pests, parasites, diseases, stress and malnutrition. We humans negatively impact our bee populations by converting their natural habitat to an unnatural habit (for them): airports, highways, housing projects, shopping malls, and parking lots. Food sources and nesting habitat for pollinators continue to shrink. Use of herbicides reduces what little bee-food resources are left. In some cases, pesticides kill insect pollinators outright. In other cases, chronic exposure to sublethal doses of pesticide residues disrupts normal development of immature pollinators."
Mussen asks that we all "consider planting bee-attractive flowers that bloom well beyond late summer into fall. The colonies require good-sized populations of well-fed bees to survive through winter."
"Also, we should consider restricting the use of pesticides to those times that pollinators are not attracted to blooming flowers or weeds. This would prevent acute bee kills, contamination of stored pollens, and unnecessary use of bodily energy for detoxification of pesticide residues."
He adds: "It's good to see that the Almond Board of California--with the help of an advisory committee comprise of scientists, beekeepers and growers--generated a packet of materials: “Honey Bee Best Management Practices for California Almonds.” The impetus: a large number of colonies suffered serious pesticide damage during the 2014 almond pollination. The packets contain an 18-page pamphlet about honey bees, their management, and their protection. Included, as well, are two heavy-duty, laminated “Quick Guides” (in English and Spanish) to be taken into the fields as reminders of best management practices. You can request the free packets by contacting the Almond Board at (209) 549-8262 or downloading the document at http://www.almonds.com/growers/pollination. The information in the packets pertains equally well to most other crop situations."
"Our bees," Mussen says, "deserve the best."
That they do.
So said Senior Extension Associate Maryann Frazier of Penn State when she addressed the UC Davis Department of Entomology and Nematology's seminar last Wednesday, April 2 in Briggs Hall.
Frazier, on a trip to California to discuss her research with the Marin County Beekeepers, took time out to travel to the UC Davis campus at the invitation of Master Beekeeper/writer Mea McNeil of the Marin County Beekeepers and associate professor Neal Williams and assistant professor Brian Johnson of the UC Davis Department of Entomology and Nematology.
Frazier, a 25-year extension specialist, expressed concern about the pesticide loads that bees are carrying, as well as the declining population of bees and other pollinators.
Beekeepers, she said, used to be much more concerned about colony collapse disorder (CCD), that mysterious phenomenon characterized by adult honey bees abandoning the hive, leaving the queen bee, brood and food stores behind. CCD surfaced in the winter of 2006, but today, when beekeepers report their winter losses, "they're not blaming CCD any more," she said.
Frazier listed the prime suspects of troubled bees as poor nutrition, mites, genetics, stress, pesticides, nosema and viruses. "Varroa mites are a huge issue," Frazier said.
Turning to pesticides, she said a 2007-2010 U.S. analysis of some 1000 samples (wax, bees and flowers) showed "an astonishing average of six pesticides per sample and up to 31 different pesticides per sample." The analysis, done by U.S. Department of Agriculture's Agricultural Marketing Service Lab (USDA/AMS) screened for 171 pesticides at parts per billion. The samples involved a CCD study, apple orchard study, migratory study and submissions from individual beekeepers.
Frazier compared the interaction of pesticides in bees to the interaction of medications in humans. When you go to the doctor, you'll be asked the names of the medications you're taking, she said. The "interaction" situation is similar to what's happening with the honey bees.
In a bee colony, lethal exposures to pesticides are easy to see, Frazier noted. "You'll see dead bees, bees spinning on their backs and bees regurgitating." But the sub-lethal effects can mean "reduced longevity, reduced memory and learning, reduced immune function and poor orientation."
Marin County Beekeepers recently undertook a similar study of pesticide analysis, raising $12,000 to do so ($300 per sample). "Marin is very mindful of pesticides, probably more than any other place," Frazier said. McNeil agreed. The results are pending publication.
"If we truly want to protect our pollinators," Frazier concluded, "three things need to be addressed or changed:
- Beekeeper reliance on chemicals and drugs to manage mites and diseases
- Pest control practices, particularly agricultural land
- The approach of more regulatory agences assessing risk and protecting the environment"
As the seminar participants left Briggs Hall, many could be heard discussing the take-home message: "average of six pesticides per sample, up to 31 pesticides per sample."
The two don't go together, but how can we protect both crops and pollinators?
"Pesticides may be necessary in today's cropping systems but large monocultures have resulted in the need for significant use of insecticides, herbicides and fungicides," says honey bee expert Maryann Frazier, senior extension associate, Penn State University.
"New chemistries, such as neonicitinoids, have their advantages but the persistent use of synthetic pesticides, especially in bee-pollinated crops and/or crops visited by bees to collect nectar or pollen, such as corn, has resulted in significant pesticide exposure to bees."
Frazier, fresh from a trip to Kenya to help beekeepers with varroa mite problems, will be on the University of California, Davis, campus on Wednesday, April 2 to discuss "The Pesticide Conundrum: Protecting Crops and Pollinators." Her seminar, hosted by the UC Davis Department of Entomology and Nematology, will be from 12:10 to 1 p.m., in 122 Briggs Hall.
"Over the past seven years our lab has analyzed over 1,200 samples of mainly pollen, wax, bees and flowers for 171 pesticides and metabolites," she said. "We have found 129 different compounds in nearly all chemical classes, including organophosphates, pyrethroids, carbamates, neonicotinoids, chlorinated cyclodienes, organochlorines, insect growth regulators, fungicides, herbicides, synergists, and formamidines. Further, we have identified up to 31 different pesticides in a single pollen sample, and 39 in a single wax sample. An average of 6.7 chemicals are found in pollen samples. However, the pesticides found most often and at the highest levels are miticides used by beekeepers for the control of varroa mites."
In her talk, Frazier will discuss these results, additional studies and concerns about "the synergistic effects of pesticides, systemic pesticides and sub-lethal impacts, including those on immune function, memory and learning and longevity, as well as the question of toxicity associated with adjuvants/inert ingredients."
Helping to coordinate the seminar with assistant professor Brian Johnson is Mea McNeil of San Anselmo, master beekeeper and writer.
Frazier, senior extension associate at Penn State for the past 25 years, is responsible for honey bee extension throughout Pennsylvania and cooperatively across the Mid-Atlantic region. Frazier works with other members of the PSU Department of Entomology to understand how pesticides are impacting honey bees and other pollinators. She's taught courses in beekeeping, general entomology and teacher education and is involved with the department's innovative public outreach program. In addition, she works with a team of U.S. and Kenyan researchers to understand the impacts of newly introduced varroa mites on East African honey bee subspecies and to help Kenyan beekeepers become more productive.
Frazier holds two degrees from Penn State: a bachelor of science degree in agriculture education (1980) and a masters of agriculture in entomology (1983), specializing in apiculture. She is a former assistant state apiary inspector in Maryland and also has worked as a beekeeping specialist in Sudan and later in Central America.
Frazier appears in a YouTube video, posted July 23, 2012 on the declining bee population. The brief clip was excerpted from Frazier's Spring 2012 Research Unplugged talk titled "Disappearing Bees: An Update on the Search for Prime Suspects." The abstract: She discusses the decline of pollinators and the prime suspects behind it. Some of these suspects include the use of pesticides, on both small and large scales, that destroy food sources for bees; agribusiness practices such as monocropping, in which the same single crop is planted year after year, eliminating the plant diversity pollinators need; stress caused by transporting the bees across country for commercial pollination needs; and threats such as nosema disease, viruses and mites.
The UC Davis Department of Entomology and Nematology plans to video-record her seminar for later posting on UCTV.