Professor Karban of the Department of Entomology and Nematology, who has maintained a study site at Bodega Marine Reserve in central California since 1982, links the decrease to temperature.
“I've been surveying seaside daisies for spittlebugs at Bodega Bay every spring for the past 35 years and found that the number of these highly visible and previously widespread insects was related to temperature,” Karban said.
However, since the spring of 2006, the UC Davis researchers have found no spittle masses on the Bodega Bay Reserve's coastal prairie. Other researchers have also detailed how sensitive spittlebugs are to environmental conditions.
The meadow spittlebugs, Philaenus spumarius, thrive in cool, moist habitats and suck plant juices, feeding on xylem fluid and excreting most of it as a foamy white mass known as spittle. The mass protects them from desiccation, predation and parasitism. In past years, Karban and Huntzinger found an abundance of meadow spittlebugs feeding onseaside daisy (Erigeron glaucus) and the non-native ice plant (Carpobrotus edulus).
The Karban-Huntzinger research paper, “Decline of Meadow Spittlebugs, a Previously Abundant Insect, Along the California Coast,” is especially important in light of alarming research in Germany dubbed “Insect Armageddon.” In that research, published last October in the journal PLOS ONE, German scientists investigated aerial insect biomass across 96 protected preserves in the country. They found that three-quarters of flying insects had disappeared over the past 25 years.
The earth's climate is warming at a rate of 0.2 degrees Celsius per decade over the past 30 year, according to the National Aeronautics and Space Administration. California's coast has also experienced climate change; the recent severely hot years in the state have also been severely dry. Models of future climates predict that the warming trend will continue and that variability in conditions, for example, droughts, also will increase in frequency and severity.
“Whether the altered climates we face globally will change our ecological communities will depend on how able individual species are to adapt to the new conditions,” the UC Davis researchers explained. “Since meadow spittlebugs were widespread and abundant, we might have assumed that they would not be threatened by climate change. What we have found is that even this species has not been able to adjust physiologically or ecologically. If the pattern they show is common, we may also see surprising changes in the abundance or distribution of other insects as well. These changes are likely to have dramatic and unexpected effects on the functioning of ecosystems.”
In a widely distributed news article released Jan. 31, Robert Sanders of UC Berkeley Media Relations wrote that Aaron Parsons, associate professor of astronomy at UC Berkeley, drafted the letter and asked his colleagues to sign it. As of Jan. 31, the signatures total more than 2300.
“With some issues, we can hope to recover from a temporary backslide, but climate change is not one of those; we cannot afford to lose these next four years,” Parsons said. “We are treading a thin line on whether it's possible to avert major climate change, and it is absolutely imperative that we do everything we can.”
The United States and 193 other nations, signed the Paris agreement last year, which went into into effect in November.
Parsons noted that President Trump and his cabinet have called climate change a "hoax" and that the administration's position is that limits on greenhouse gas emissions, especially by coal-fired power plants, would stifle the economy.
California Gov. Jerry Brown publicly announced that the state will launch its own satellite if Trump shuts down climate monitoring satellites now operated by NASA.
Parsons advocates empowering scientists and intellectual leaders, urging them to be more active on these issues. "I hope we can build a voting base grounded in science and learning to oppose this anti-intellectualism we are seeing,” he said.
Parsons, through the UC Berkeley Government and Community Relations Office, has also shared the open letter with California politicians in a call to action.
"We the undersigned are calling on you, in the most urgent terms possible, to maintain our country's commitment to meeting the greenhouse gas emission targets set forth in the Paris Climate Agreement. This agreement is the first of a series of steps required to avert substantial climate change. The Earth's climate is entering a state that has not been experienced in human history. Continuing to produce greenhouse gases at current rates will have catastrophic, unstoppable consequences for our environment, our economy, and our country. Bold and decisive action may still avoid the worst scenarios, allow for adaptation to the changes, mitigate the damage, and bring new economic opportunities to our country. To this end, we ask that you ensure America's place as the global leader on climate action.
"With this letter, we aim to express the degree to which the scientists and intellectual leaders of our state, speaking for themselves and not on behalf of their respective employers, agree on the facts of climate change. Despite misleading portrayals, there is widespread consensus in the scientific and academic communities that human-caused climate change is real, with consequences that are already being felt. The science of how greenhouse gases trap heat is unimpeachable. Climate records are being broken as human-caused changes add onto natural oscillations (e.g., El Niño) in the climate system. Fossil records from pre-human times show much higher sea levels and a reorganization of vegetation patterns when greenhouse gases were higher and Earth's climate was much warmer than today. Increasing levels of greenhouse gases in our atmosphere set in motion regional variations in weather, weather extremes, the loss of major ice sheets, and declining biodiversity that has been associated with mass extinctions in Earth's past.
"Scientists have warned for decades of the dangers of overreliance on fossil fuels. The world has been slow to respond and, as a result, we run an increasing risk of major damage to America's economy and security. We have had an unusually large number of serious natural disasters in the past decade that are in line with climate change predictions. The Southeast and West suffer from increasing droughts. Miami floods at high tide as sea levels rise. Major cities on the Eastern and Gulf coasts regularly suffer major damage from violent weather. Western forests die because winters are insufficiently cold to prevent insect infestation of drought-stressed trees. Left unchecked, the frequency and severity of these climate change events will increase with time, as will their economic impact. To secure and conserve our way of life, our economy, and our environment, we need immediate action.
"The United States now has a unique opportunity to lead the world in developing innovative ways to reduce greenhouse gas emissions. By investing in and incentivizing clean energy and carbon sequestration technologies now, we position ourselves to be the economic and political leaders of the 21st century. To do otherwise cedes these opportunities to others and undermines our national security, food security, water security, and the future of our children and grandchildren. For these reasons, we ask you to maintain and increase our country's commitment to taking action on climate change, beginning with the current Paris Climate Agreement."
Among the UC Davis Department of Entomology and Nematology signing the letter as of Jan. 31:
- Louie Yang, Associate Professor
- Rachel Vannette, Assistant Professor
- Richard Karban, Professor
- Sharon Lawler, Professor
- James Carey, Professor
- Philip Ward, Professor
Further information is available from Parsons at firstname.lastname@example.org.
DAVIS--Steven Frank, assistant professor of biology, North Carolina State University, Raleigh, will speak on "Can Forests Take the Heat? Managing Pests and Ecosystem Services in a Warming Climate" from 12:10 to 1 p.m., Wednesday, Feb. 18 in 122 Briggs Hall.
"Trees help mitigate the urban heat island effect and provide other services to urban residents," Frank says in his abstract. "Unfortunately, herbivores are often more abundant and damaging on urban than rural trees. We have found that urban warming increases pest abundance directly and indirectly by changing interactions with parasitoids. Our goal is to determine how urban warming and pests interact to affect tree health and the services they provide. We want to determine if cities, which have been warming for centuries, may be canaries in the coal mine that can predict the effects of global warming on natural forests."
Frank completed all three degrees (bachelor's, master's and doctorate) at the University of Maryland where he was advised by Paula Shrewsbury and Bob Denno. He spent a year as a postdoc at Texas A&M before joining the faculty of North Carolina State University in 2007. His research focuses on understanding how urbanization and climate change affect tree pests, pollinators, and ecosystem services. He also conducts research on optimizing IPM and biological control in greenhouses, nurseries, and landscapes.
Plans call for video-recording the seminar for later posting on UCTV.
See pending seminars on this page.