BY LARRY MASTER
Wednesday evening the Wild Center with AdkAction hosted a presentation by Dr. Christina Grozinger, distinguished professor of entomology and director of the Center for Pollinator Research at Penn State University. The research center is home to the largest group of pollinator researchers in the world. Following a reception at 6 p.m., Groizinger addressed an attentive audience from 7-8 p.m., a lecture that will be repeated Thursday evening at the View in Old Forge. The lecture is free and open to the public.
Grozinger explained that pollination is the transfer of pollen from male flowers to female flowers, an act that is essential for plant reproduction. Although some plants can be pollinated by the transport of pollen by wind, more than 80 percent of the world’s flowering plants and almost three-fourths of our major food crops depend upon insects and other pollinators.
Bees are the most important pollinators, and flower-bee “mutualisms” are the product of millions of years of evolution. Flowers attract bees and other pollinators by providing nectar “rewards” and by physical adaptations that help ensure that pollen will be transported to other flowers by the pollinators. Honeybees, in turn, have developed hairy bodies and legs adapted to carry pollen back to their hives to provide protein and micronutrients to feed young developing bees.
Many of these mutualistic adaptations are very specific, with the plant evolving to attract a particular pollinator species and that species evolving to pollinate that particular plant species. The pollinator benefits by exclusive access to the nectar reward, and the plant benefits by reducing the risk of misdelivered pollen. Perhaps the most famous example of this is an orchid flower, sent to Charles Darwin in 1862 from Madagascar, with a nectary almost a foot removed from the orchid’s opening. Darwin hypothesized that there must exist an unseen moth with a proboscis 10-11 inches long so as to be able to access the nectar and transfer pollen. It was not until 1992, more than 130 years later, that Darwin’s conjecture was confirmed with the discovery and video recording of the moth!
After bees, flies are the next most important group of pollinators. They pollinate strawberries, onions, and carrots and are particularly important pollinators of wildflowers in arctic and alpine habitats. Other pollinators include wasps, butterflies and moths, beetles, bats, and hummingbirds.
One reads headlines in the popular press about the “collapse” of pollinators, most notably honey bees, and one also reads that there is no collapse. So what is really happening? While there is always some loss of honeybee colonies totaling perhaps 15 percent annually, Grozinger and her colleagues have shown that total annual losses of bee colonies over the past decade have been 30-40 percent.
In Pennsylvania, where Grozinger’s lab is located, 52 percent of the honeybee colonies were lost last winter. Yet the data also show that the number of honeybee hives in the United States has remained stable or even increased slightly over the past decade or more. Again, what is happening here? Grozinger explained that beekeepers are simply replacing their colonies, by splitting hives and buying new colonies—both common practices.
There is much less data on what is happening with native bees (more than 4,000 species in the U.S. and 450 in New York State) and other pollinators as long-term studies are few. But we do know that half of the bumblebees studied in the U.S. and Europe are declining. The Xerces Society lists 57 bee and 59 butterfly species on its “Red List” of declining pollinator species, and NatureServe lists hundreds of pollinators as imperiled or vulnerable to extinction. Most of us recognize that we are seeing many fewer monarch butterflies in recent years, and Grozinger explained that based on surveys of their wintering habitat in Mexico, there has been an 80 percent decline in monarchs!
So what are the causes of these documented declines in pollinators? Grozinger explained that there are a number of causes for these declines including parasites (e.g., varroa mites in honeybee hives), viruses (25 identified so far for honeybees, many of which are transferable to native bees), loss of feeding and nesting habitat, climate change (e.g., leading to less nectar production; leading to a mismatch between flowering and pollinator activity), and pesticides.
Grozinger spent some time discussing the impacts of chemicals on bees, especially honeybees where the issue has been most studied. At least 139 chemicals (ingredients in pesticides, fungicides, and herbicides) have been identified in honeybee hives with the average hive having six of these chemicals, and 90 percent of hives having at least one chemical. These chemicals have both lethal and sublethal effects on bees, including reduced foraging and feeding activity and lowered reproduction. Although pesticide use declined 59 percent from 2002-2012, the toxicity increased by 73 percent due to new more toxic chemicals coming on the market. Testing for effects on non-targets and testing for sublethal effects are not part of the protocols when the EPA licenses the use of new pesticides and fungicides.
Perhaps foremost among the chemical culprits are bee-killing neonic pesticides, especially clothianidin and thiamethoxam. Their use has greatly expanded in the last ten years in corn, cotton, and soybean seed coatings, such that farmers concerned about using these chemicals have trouble finding seeds that are not treated. Moreover, a study by the Environmental Protection Agency has shown that the use of these seeds does not increase crop yields as beneficial insects are lost and herbivore (slug) populations increase. But as Grozinger explained, there are many appropriate and suitable uses for neonictinoids, so a total ban on these chemicals as is proposed in Europe may not be appropriate. Rather, a selected ban that reduces the impact of these chemicals on non-targets should be pursued. (The EPA is receiving public comments until July 24 on these neonic pesticides.)
Grozinger concluded her presentation by discussing things that we could all do to benefit pollinators. These include the following:
- Create a pollinator garden. See Xerces Society guides: Attracting Native Pollinators, Gardening for Butterflies, 100 Plants to Feed the Bees, Farming with Native Beneficial Insects, Farming for Bees, and others.
- Create nesting habitat for pollinators. See Xerces Society guide: Managing Alternative Pollinators.
- Use fewer chemicals, especially pesticides, fungicides, and herbicides. Follow “Integrated Pest Management” protocols: prevent introduction of pests; monitor levels, use multiple non-chemical methods; understand tolerance thresholds. See http://www2.ipm.ucanr.edu/beeprecaution/
- Increase awareness of pollinators – their importance and what we can do in our local communities to benefit native pollinators.
- Advocate for pollinators at local, state, and national levels.
- Keep honey bees. But do this only if you are fully prepared to do the work to manage the hives.
See the New York State Pollinator Protection Plan (June 2016) for lots of good advice. http://www.dec.ny.gov/docs/administration_pdf/nyspollinatorplan.pdf
Professor Grozinger has received national and international recognition for her research. She has presented over 35 invited seminar or symposia lectures in the last five years, including plenary and keynote lectures at the 2010 Congress of the International Society for the Study of Social Insects in Denmark and the 2011 International Society for the Study of Chemical Ecology conference in Vancouver, Canada. She was awarded the National Science Foundation Faculty Early Career Development (CAREER) Award and the Penn State Harbaugh Faculty Scholars Program Award for Excellence in Teaching and Learning, among other honors.
These events are part of the Adirondack Pollinator Project is a project of AdkAction in partnership with the Wild Center, Lake Placid Land Conservancy, and Common Ground Garden in Saranac Lake. The Wild Center is located at 45 Museum Drive, Tupper Lake. For more information visit their website. View is located at 3273 NY-28, Old Forge, for more information visit their website.
More information about AdkAction’s Pollinator Project and project partners can be found here.
Leave a Reply