Posts Tagged: pesticides
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."
A queen bee and her colony at the Harry H. Laidlaw Jr. Honey Bee Research Facility, UC Davis. (Photo by Kathy Keatley Garvey)
Maryann Frazier with the list of 171 pesticides screened in the U.S. survey. (Photo by Kathy Keatley Garvey)
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.
Maryann Frazier inspects a hive. (Photo courtesy of Penn State)
Honey bees thriving at the Harry H. Laidlaw Jr. Honey Bee Research Facility, UC Davis. (Photo by Kathy Keatley Garvey)
The California Gold Rush (1848-1855) has nothing on honey bees.
Sometimes foraging honey bees are covered with their own kind of gold--pollen--or protein for their colonies.
We saw this honey bee dusted with gold from head to thorax to abdomen as she gathered pollen from blanket flowers (Gaillardia). Her flight plan seemed uncertain, as her load was heavy and her visibility, poor. She struggled to take off, but take off she did.
Speaking of the Gold Rush and honey bees, entomologists always associate the arrival of honey bees in California with the California Gold Rush. That's because honey bees were introduced to California in 1853, right in the middle of the Gold Rush.
Back then, the hills were covered with wildflowers where bees gathered nectar (carbohydrates) and pollen (protein). Today, however, scientists are worried about bee malnutrition.
"Honey bee colonies need a mix of pollens every day to meet their nutritional needs," says Extension apiculturist Eric Mussen of the UC Davis Department of Entomology and Nematology. "In fact, they should have a one-acre equivalent of blossoms available to them daily to meet their demands. They can fly up to four miles from the hive--a 50-square mile area--to gather that food and water (and propolis, plant resin)."
A worried beekeeper recently asked him about the declining bee population and wondered why his own colonies were dwindling. In addition to malnutrition, Mussen listed a few other possibilities:
Varroa mites – "They suck the blood from developing pupae and adult bees, shortening their lifespans. They vector virus diseases, the easiest to see being deformed wing virus. If you have adult bees around the colony with curly, undeveloped wings, then you have too many mites. If you see mites on the bees when you look in the hive, that is too many mites."
Nosema ceranae and other diseases – "You need a microscope to see the spores of a Nosema infection. Go to Randy Oliver’s webpage, Scientificbeekeeping.com, and look at the information on Nosema ceranae and spore counting."
Contact with toxic chemicals – "Since your bees can fly up to four miles away to forage, that also is the distance within which they can get into trouble with bee-toxic chemicals. It is not likely that the organic farm is a source. However, if there are other farms around, or if your neighbors (golf courses, shopping centers, parks, playgrounds, etc.) are having problems with sucking or chewing insects, they may have used one of the neonicotinoids on their shrubs or trees. Turf and ornamental dosages are considerably higher than those used in commercial agriculture. So, the amounts of toxins in nectar and pollens can be toxic to honey bees and other pollinators."
Mussen also acknowledged that California buckeye blossoms are toxic to bees. "This was a fairly dry spring," he said. "Not too many weeds and wildflowers were around when the California buckeye came into bloom. Buckeye pollen is toxic to developing bee brood and to adult bees, if it gets to be their primary food source in the colony."
The problem could also be due to other issues as well, Mussen said. "Maybe the queens did not mate with enough drones, or the queens got too hot or too cold during their journeys to your hives, etc."
"As beekeepers, it is up to you to stick your nose in the hive, look at everything and try to determine what may be going wrong. If you are feeling way too new at this to have any idea of what is going on, then contact your local bee club--there is one in practically half of the California counties--and find someone to help access your problems."
And the pollen, that precious protein? "When beekeepers examine their hives, they should see a good supply of pollen with many colors," Mussen says.
Honey bee is covered with pollen from a blanket flower, Gaillardia. (Photo by Kathy Keatley Garvey)
Honey bee is dusted with pollen from the blanket flower. (Photo by Kathy Keatley Garvey)
Lift off? The bee struggles to take off. (Photo by Kathy Keatley Garvey)
Honey bee expert Eric Mussen of UC Davis offers some good advice in a piece that he and commercial beekeeper Gene Brandi of Los Banos wrote in the current edition of CAPCA Advisor, published by the California Assoiciaton of Pest Control Advisors.
Mussen, an Extension apiculturist and member of the UC Davis Department of Entomology faculty, and Brandi, a long-time beekeeping legislative advocate, emphasized these two points:
1. The best way to protect honey bees from damage by pesticides is to keep them from being exposed.
2. To prevent negative effects of pesticides of all types, do not apply them to blooming plants upon which the bees are foraging.
Pesticides can have "negative effects on queens, drones, developing brood and bee behavior that eventually result in weakened or dead colonies," they wrote.
Honey bees can die from injesting pesticides on plants and in contaminated water. Or they can be accidentally sprayed, such as when they cluster on beehives on hot evenings and are "hit by applications from directly overhead or by pesticide drift."
Bees carry pesticide residue back to the hive. "All types of pesticides contain some products that are toxic to developing honey bee brood," they wrote.
"It would be nice to think that we know all about the effects of pesticides on adults and immature honey bees, but that just is not the case."
What we do know is that honey bees pollinate about a third of the agricultural crops produced in the United States and the bee population is decreasing.