This quote, often falsely attributed to Mark Twain, is a favorite of Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis.
Speaking at the second annual Butterfly Summit last Saturday, May 26 at Annie's Annuals and Perennials, Richmond, Shapiro discussed his research and offered his observations and views on the state of butterflies. He maintains a website at http://butterfly.ucdavis.edu/
Shapiro has monitored butterfly population trends on a transect across central California for 46 years. The 10 sites stretch from the Sacramento River Delta through the Sacramento Valley and Sierra Nevada mountains to the high desert of the Western Great Basin. Shapiro visits his sites every two weeks "to record what's out." The largest and oldest database in North America, it was recently cited by British conservation biologist Chris Thomas in a worldwide study of insect biomass.
"The vast majority of the butterflies we monitor are emerging earlier in the year now than they were in the 1970s," Shapiro said. He mentioned the Red Admiral butterfly, Vanessa atalanta, which spends the winter as an adult, is "our biggest responder to global warming, coming out 21 days earlier on average that it use to, exactly the same in England, same species. It's not weird at all. It is winter active."
His research shows that not only are butterflies coming out earlier, but "we also find trends in population and species richness."
Shapiro, a member of the UC Davis faculty since 1971 and author of the book, Field Guide to Butterflies of the San Francisco Bay Area and Sacramento Valley Regions, said that "in a nutshell, at low elevations, butterfly faunas have been declining slowly until 1999. In 1999, 17 species had an abrupt fall in abundance, spontaneously. On its face, this was a non-random event. The decline was then rapid from 1999 to the onset of the recent drought and then things went up again."
Shapiro noted that by and large, immature butterflies spend the winter underground or right at the surface. "This is the worst possible environment for overwintering butterflies in the early stages, what with the combination of warm and wet." The high humidity and temperature are very favorable for fungal and bacterial pathogens, he said, adding that "Overwintering survival in warm wet conditions is poor."
"When we have a dry winter, it's colder at night but not cold enough to be lethal, he said. "It's a healthier environment to be an overwintering caterpillar. That's what we think is going on."
In the mountains or higher elevations, changes are strongly correlated with climate. "As it gets too warm and dry down below, butterflies are moving uphill, but plant resources are moving up the slope more slowly. When resources are not available yet higher up, butterflies have a real problem. There's no where to go at all for truly alpine species; they're already at the top of the mountain. The next stop is heaven." Shapiro described the decline of butterfly populations in the mountains as "worrisome."
Neonicotinoids, which Shapiro defined as "a class of synthetic pesticides chemically derived from the chemistry of nicotine," are often targeted as a cause of butterfly decline. "Neonics are not in Scotland and there's been no butterfly decline in Scotland," he pointed out. "But, anyone who has taken a statistics course knows that Correlation Is Not Causation."
Turning to monarchs, Shapiro said "More than half of the questions I get from the public deal with monarchs."
Describing the monarch as "the poster child for conservation," Shapiro said: "There's a lot of stuff out there in the media, and it's not all to be believed." Butterfly population counts differ from summer breeding data and the overwintering data.
"If you want the scoop on monarchs--unconnected with fundraising or politics," he said, "read Anurag Agrawal's book, Monarchs and Milkweed." The book is subtitled "A Migrating Butterfly, a Poisonous Plant and their Remarkable Story of Coevolution." Agrawal, the James A. Perkins Professor of Environmental Science at Cornell University, Ithaca, N.Y., received his doctorate in population biology from UC Davis in 1999.
"Monarchs in California have had a long decline, perhaps more dramatic than the decline in the Midwest and the East," Shapiro said, adding they have never been as common in California than they are in the East. "If they're relatively scare, that doesn't mean a decrease. We need to do comparisons over time. During the drought, they came back. We don't know why."
Shapiro also said that monarchs are winter-breeding in California, something they didn't do 10 years ago. "It started in southern California, maybe a decade ago and is now spreading to the inland empire. They're well established in the East and South Bay." He said he heard one report of monarchs winter-breeding in Woodland, Yolo County.
"Monarchs can't breed in the winter here under natural conditions," Shapiro said. "A non-native, non-dormant milkweed, tropical milkweed (Asclepias curassavica) allows winter breeding. These plants are often contaminated with the parasite, Ophryocystis elektroscirrha or OE, a problem in Southern California, but not yet in northern California. "People who are really committed to native plants would like you to get rid of your exotic tropical milkweed and replace it with native species that go dormant." He recommends "cutting them back three times a year" to allow fresh new growth.
Some of his take-home messages:
- Butterfly faunas are declining in most parts of the North Temperate Zone where monitoring is done. The most severe declines have been in European grassland faunas. By those standards, we're not that bad off (yet?).
- At low elevations in California, declines were moderate until 1999, when they accelerated abruptly. Our multivariate statistical analyses suggest (but cannot prove!) that climate change has been only a minor factor, while habitat conversion and loss, and loss of habitat connectivity share the blame equally with pesticides, specifically neonicotinoids.
- At higher elevations in the Sierra Nevada, species at tree-line have declined in response to climate change but there have been no losses attributable to habitat conversion or pesticides. Many species are moving upslope (or trying to, because they are more mobile than their essential plant resources).
- The recent “1000-year drought” had dramatic impacts. At low elevations, butterfly faunas rebounded from recent lows, probably due to a better environment for overwinter survival. In the mountains the opposite happened: lack of snow cover led to poor overwinter survival and faunas plummeted to unprecedented lows at places like Donner Summit. The heavy snow pack of winter 2016-17 did little to improve things, because the number of animals going into overwintering was already so low.
- We are already seeing low-elevation faunas slipping back into decline. Because most montane butterflies have only one generation a year, it will take several favorable years to rebound from the losses there.
- Our research revealed that California monarch populations had been in decline for decades, perhaps more so than in the East and Midwest.
- This was true even though the usual “suspect” causes – GMOs and milkweed shortages – do NOT appear to apply here.
- There was also a change in the seasonal breeding pattern of monarchs during the worst of the decline.
- During the drought, monarch populations rebounded significantly here, and their historic seasonal breeding pattern returned. But this year we seem to be going back to pre-drought patterns.
- Winter breeding by monarchs began in Southern California several years ago and has now spread to the Bay Area. Overwintering monarchs are supposed to be in reproductive diapause cued mainly by daylength. Why a growing percentage of them are not is a mystery which has not been solved as of this afternoon.
Ironically, it occurred the first day of National Pollinator Week.
Sujaya Rao, an Oregon State University (OSU) entomologist working the case, will be speaking on "The Buzz on Native Bumble Bees in Western Oregon: Why They Thrive and Die," from 12:10 to 1 p.m., Wednesday, May 18 in Room 230 of Wellman Hall. The talk, hosted by the UC Davis Department of Entomology and Nematology, is open to all interested persons.
Scientists attributed the massive bumble bee die-off to the active ingredient Dinotefuran, a neonicotinoid.
The Oregon Department of Agriculture (ODA) then put temporary restrictions on the use of 18 pesticides containing Dinotefuran.
The Xerces Society for Invertebrate Conservation was appalled by the die-off, as many of us were--and still are. Mace Vaughan, the Xerces Society's pollinator conservation director, said in a press release: “To our knowledge, this incident is the largest mass poisoning of bumble bees ever documented, and thankfully ODA is taking the issue very seriously. After interviewing the landscaping company that maintains dozens of ornamental trees around the Target parking lot, ODA investigators learned that the pesticide Dinotefuran had recently been applied. Investigators confirmed that Dinotefuran, sold under the trade name ‘Safari,' belongs to a class of insecticides called neonicotinoids that have been linked to bee deaths in recent years."
“Because neonicotinoids are long-lasting in plant tissues and can be found in flower nectar and pollen, and because they have been implicated in the global decline of honeybees, there have been growing concerns about their safety for pollinators,” the Xerces Society related in the press release.
Scott Black, executive director of the Xerces Society, noted that the pesticide was applied to the tree while it was flowering, an action that violates the product's instructions. “Beyond the fact that a pesticide was applied to plants while they were attracting large numbers of bees, in this case the pesticide was applied for purely cosmetic reasons. There was no threat to human health or the protection of farm crops that even factored into this decision.”
Rao, an OSU professor and field crop entomologist, specializes in pest management in grass seed and rotational crops, as well as native bee pollinators in agricultural and native landscapes. On her website, she lists her native bee research objectives as:
Determine the diversity and abundance of native bees in diverse cropping systems and surrounding habitats, and evaluate the impacts of bumble bees and honey bees in pollination. Specific areas of research:
- Red and arrow leaf clover
It's difficult to think of 50,000 bumble bees dying.
How long has it been since you've seen a bumble bee? Last weekend a yellow-faced bumble bee, Bombus vosnesenskii, buzzed into our Vacaville yard and foraged in the foxgloves.
Then last week, another bumble bee, the black-faced Bombus californicus, frequented the "Purple Ginny" sage (Salvia coahuilensis) in the Häagen-Dazs Honey Bee Haven on Bee Biology Road, UC Davis. Operated by the UC Davis Department of Entomology and Nematology, the half-acre bee garden is open from dawn to dusk.
Now if we could just do more to protect the pollinators...
An educational opportunity to learn more about them--the truths and the myths--will take place on Wednesday, Sept. 9 at the University of Caifornia, Davis, and you're invited. It's open to the public.
The conference, themed “Truth or Myth: Neonicotinoids and Their Impact on Pollinators: What Is the Science-Based Research?” will take place from 10 a.m. to 4 p.m. in the UC Davis Conference Center, 550 Alumni Lane.
UC Davis researchers and state officials will address the crowd, announced conference coordinator Dave Fujino, director of the UC Davis-based California Center for Urban Horticulture.
“We are pleased to have such a knowledgeable lineup of UC Davis researchers who will clarify the issue of impact of neonicotinoid impacts on pollinators by summarizing and presenting the past and current science-based research,” Fujino said. “We are also fortunate to have additional presentations on the regulation guidelines on neonicotinoids and their role in controlling invasive pests in California, and a diverse group of stakeholders participating in a panel discussion on the neonicotinoid issue.”
Neonicotinoids, recently implicated in the worldwide die-off of pollinators, including honey bees, are a class of neuro-active insecticides chemically similar to nicotine. Considered important in the control of many significant agricultural and veterinary pests, they target the central nervous system of insects, resulting in paralysis and death. “Neonics,” as they're called, are commonly used on farms, and around homes, schools, and city landscapes.
Michael Parrella, professor and chair of the UC Davis Department of Entomology, will provide an overview of the current use of neonicotinoids and the role of honey bees in California agriculture. Six other speakers are scheduled, along with a panel discussion.
The speakers include:
- Brian Leahy, director of the California Department of Pesticide Regulation, who will discuss “California Pesticide Regulation of Neonicotinoids”
- Nick Condos, director of the Plant Health and Pest Prevention Services Division, California Department of Food and Agriculture, “Neonicotinoid Risks Associated with Invasive Species Management”
- Karen Jetter, associate project economist, UC Agricultural Issues Center, “Trends in Neonicotinoid Usage in California Agriculture and the Control of Invasive Species”
- Margaret “Rei” Scampavia, a doctoral candidate who studies with major professors Neal Williams and Ed Lewis of the UC Davis Department of Entomology and Nematology, “Past Neonicotinoid and Bee Research”
- Elina Lastro Niño, Extension apiculturist based at the Harry H. Laidlaw Honey Bee Research Facility, UC Davis, “Current Neonicotinoid and Bee Research.”
The California Center for Urban Horticulture (CCUH) will co-host the event with the UC Davis Department of Entomology and Nematology and the UC Agriculture and Natural Resources.
Sponsors include California Association of Nurseries and Garden Centers (CANGC), a trade organization founded in 1911 to promote and protect the California nursery industry; Four Winds Growers, based in Winters, Calif.; Scotts Miracle-Gro, a company headquartered in Marysville, Ohio, and known as the world's largest marketer of branded consumer lawn and garden products; and Monrovia, a horticultural craftsmen company headquartered in Azusa, Calif.
At the close of the conference, Fujino will preside over a panel discussion on neonicotinoid issues and concerns. Questions and answers from the audience will follow. The panel is to include a UC Cooperative Extension farm advisor, and representatives from the California Association of Nurseries and Garden Centers, Home Depot, Scotts Miracle-Gro, Bayer CropScience and the American Beekeeping Federation.
The registration fee of $50 will include lunch, as well as the post-conference social hour. To register, access the CCHU website at http://ccuh.ucdavis.edu/public/copy_of_public/neonicotinoid-pollinator-conference-2015/neonic or contact CCUH representative Kate Lincoln at firstname.lastname@example.org or (530) 752-6642.
The European Union recently adopted a proposal to restrict the use of three pesticides belonging to the neonicotinoid 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.
(Editor's Note: Like Bug Squad on Facebook)