- Author: Kathy Keatley Garvey
It's in the current edition of The American Entomologist.
The UC Davis team, captained by Mohammad-Amir Aghaee of the Larry Godfrey lab, included members Danny Klittich of the Michael Parrella lab; Jenny Carlson, Anthony Cornel lab; Margaret "Rei" Scampavia, Neal Williams/Edwin Lewis lab; and Ralph Washington Jr., Steve Nadler lab.
The UC Davis debate team was assigned the “con” side of the topic, “Neonicotinoids Are Causing the Death of Bees Essential for Pollinating our Food Crops. The Use of Neonicotinoids Should End.” Auburn (Ala.) University drew the “pro” side. UC Davis defeated Auburn University and then went on win the overall student debate championship in the six-team, three-topic competition.
The neonicotinoid debate drew widespread attention. Below are the summaries distributed here in open access, Creative Commons:
TOPIC
Neonicotinoids are causing the death of bees essential for pollinating our food crops. The use of neonicotinoids should end.
Unbiased Introduction
Alix Whitener
Washington State University
Honey bees, bumble bees, and solitary bees are among the important biotic couriers transporting pollen from the male anther to the female stigma of flowers, playing a fundamental role in the fertilization and fruiting of angiosperms. The mutualism between bee pollinators and flowering plants is essential to approximately 35% of global agriculture (Velthuis and van Doorn 2006, Klein et al. 2007) and critical to many aspects of native ecosystems worldwide. However, this critical link is threatened by the decline of bee populations. The source of bee decline is multi-faceted; suspected causes of colony collapse disorder (CCD) in honey bees include, but are not limited to, biotic factors such as parasitic mites, pathogens, and resource availability/diversity, as well as abiotic factors including climatic change, land-use change, pollution, and pesticides (Decourtye et al. 2010, Neumann and Carreck 2010, Kluser et al. 2011, Girolami et al. 2012). The decline of native North American pollinators has the potential to disrupt the integrity of ecosystems and agricultural prosperity (Cane and Tepedino 2001). Native bee decline could be due to a number of reasons: the establishment of monocultures and disturbance of their native habitat; disruption in the pattern of bloom; the replacement of native flora with crop plants; or widespread insecticide use (Cane and Tepedino 2001). Among the classes of insecticides registered today, neonicotinoids are one of the most used insecticides worldwide, and are at the forefront of the investigation to determine the contributing factors to CCD (Girolami et al. 2012).
Neonicotinoid insecticides are effective against a broad range of chewing and sucking insect pest species (Zhou et al. 2013) and are registered for use in a wide variety of crops, including cereals, corn, cotton, oilseed rape, sunflowers, and sugar beets. This insecticide can be applied as a highly effective systemic seed coating, in the form of foliar sprays, or incorporated as a soil drench (Elbert et al. 2008, Yang et al. 2008, Blacquiére et al. 2012). All neonicotinoids are agonists of the insect nicotinic acetylcholine receptor (nAChR) (Matsuda et al. 2001, Elbert et al. 2008), causing excitation of the nervous system, paralysis, and eventually death of exposed, susceptible insects. While neonicotinoids are generally considered selective for insects and safe against mammals and birds, beneficial arthropods are still susceptible. Beneficial insects can come in contact with neonicotinoids if they feed on contaminated plant tissues or excretions, or are consequently exposed to the insecticide by ingesting contaminated prey (Prabhaker et al. 2011). When applied according to label instructions, neonicotinoids are not likely to come into direct contact with blooms, reducing contact with pollinators. However, neonicotinoids are highly potent and effective systemically; this class is highly soluble in water and can be moved by the plant translaminarly (Girolami et al. 2009).
Because of the value of pollination services provided by bees, and the widespread use of neonicotinoids, it is critical that the role of these pesticides in pollinator decline be determined. This will allow for informed decisions regarding future use of this class of pesticides.
Pro Side
Julian Golec, Matthew Burrows, C. Scott Clem, Adekunle Adesanya, Zi Ye, and Olufemi Ajayi
Auburn University
Advisor: David Held
Overwhelming evidence points to neonicotinoids as a critical factor in population declines of honey bees, bumble bees, and solitary bees (Sandrock et al. 2014). Neonicotinoids are the most widely used insecticide in agroecosystems due to their systemic properties (Hopwood et al. 2012), yet the impacts of neonicotinoids on bees extend beyond their use in agricultural settings. In urban settings, neonicotinoids can be applied at rates 120 times greater than those approved for agricultural settings (Hopwood et al. 2012). As a result, treated plants retain unmetabolized, active residues in virtually all plant parts, including pollen, nectar, and guttation fluids (Girolami et al. 2009). The effects of neonicotinoids vary based on the duration (acute or long-term exposure), route of exposure (oral or contact), and the bee species tested (Hopwood et al. 2012). In addition to outright mortality of individual bees, there are also sublethal effects implicated that affect bees at the colony level. For example, decreases in bumble bee queen production, pollen foraging efficiency, worker size, the rate of larval development, and learning abilities have all been implicated as sublethal effects of neonicotinoids (Decourtye et al. 2004, Gill and Raine 2014, Whitehorn et al. 2012). Additionally, these chemicals have been documented to affect immune responses in bees, making them more susceptible to pathogenic infections such as viruses and Nosema microspores (Alaux et al. 2010). Moreover, synergistic interactions between neonicotinoids and fungicides have been documented (Iwasa et al. 2004), which may indicate interactive effects with other chemical classes, increasing the negative impact on bees.
Current risk assessment protocols regarding the impacts of neonicotinoids on honey bees are insufficient, as they are focused on acute toxicity levels and do not incorporate various routes of exposure (Blacquiére et al. 2012). Shockingly, assessments for native bees are virtually nonexistent (Hopwood et al. 2012). Due to these factors, the U.S. Environmental Protection Agency (EPA) has recently called for a review of the current protocols in order to develop new risk assessment parameters (EPA 2012). Ahead of the U.S., the European Union (EU) has temporarily banned the use of neonicotinoids until further research can address sublethal and synergistic effects (van der Sluijs et al. 2013). The U.S. should follow the efforts of the EU and temporarily ban the use of neonicotinoids before irreversible damage occurs to an already stressed food industry and an increasingly less diverse ecosystem.
Historically, the 1996 Food Quality Protection Act (FQPA) restricted the use of toxic organophosphates, which lead to the creation of a new and presumably “safer” class of insecticides: the neonicotinoids (van Steenwyk and Zalom 2005). However, research has primarily focused on the European honey bee (Apis mellifera L.), and a few native bees (e.g. Osmia lignaria Say). It has since been found that the neonicotinoids are not a suitable alternative to older chemistries (Abbott et al. 2008). By using precedents set forth by the FQPA, the U.S. should temporarily cease the use of neonicotinoids until their effects at both the individual and colony levels can be thoroughly understood. We believe that a temporary ban on this insecticide class will lead to the discovery of new and safer insecticides, ultimately replacing the neonicotinoids.
Con Side
Mohammad-Amir Aghaee, Jenny Carlson, Daniel Klittich, M. Rei Scampavia, and Ralph Washington, Jr. University of California, Davis
Advisor: Michael Parrella
However, the relationship between neonicotinoid use and pollinator decline remains disputed. Neonicotinoids were registered as reduced-risk pesticides because of their insect-specific action and low mammalian toxicity (van der Sluijs et al. 2013). They were selected to replace the organophosphates, carbamates, and pyrethroids, which have known non-target effects on humans and wildlife (Fairbrother et al. 2014).
Acute and chronic studies have shown that neonicotinoids are toxic to honey bees and bumble bees (Blacquiére et al. 2012). However, numerous studies implicating neonicotinoids as a cause of honey bee losses are insufficient in rigor and depth. Studies testing toxicity at field-realistic dosages between 1-10 ppb have shown inconsistent results (Cresswell et al. 2012). In addition, not all neonicotinoids have the same level of toxicity to bees. Acetamiprid and thiacloprid have an LC50 that is five orders of magnitude less toxic than clothianidin, thiamethoxam, and imidacloprid (Brown et al. 2014).
In addition, many other factors have been documented as contributing to pollinator decline (United States Department of Agriculture [USDA] 2013). Varroa destructor (Anderson and Trueman), a mite that feeds on the hemolymph of pupae and adult bees, vectors deformed wing virus and is a principal component of colony declines. Acaricides used to control Varroa are ubiquitous in wax comb of honey bee hives. These chemicals have been shown to compromise immune response in bees, impair honey bee behavior, and reduce the number of queens (Boncristiani et al. 2012). Pathogens such as Nosema ceranae (Fries) have impacted domesticated honey bee colonies, and N. bombi (Fantham and Porter) has wreaked havoc on native bumble bee populations (Mayack and Naug 2010, Evans and Schwarz 2011).
The lack of adequate nutrition further stresses colonies (Naug 2009). This results from a combination of habitat fragmentation and land-use changes that reduce the amount of wild forage available to honey bee colonies during periods of low food supply. Native pollinator populations are especially sensitive to habitat fragmentation and loss (Potts et al. 2010). This problem is compounded by the increasing demand for pollination services in agriculture (Aizen and Harder 2009).
Pollination demand created by almond production exemplifies the synergy of all these factors against honey bees. Every February, over two million colonies are moved to California to pollinate the almond bloom. Colonies are placed in staging areas at high concentrations and fed artificial diets to supplement a lack of natural forage (Fairbrother et al. 2014). These are optimum conditions for transmitting viruses and mites between colonies.
The best approach towards addressing pollinator declines would be to improve management practices to protect pollinators in crops (USDA 2013). This includes banning certain application strategies such as seed treatments. To this end, regulatory agencies need to have stricter registration guidelines that incorporate more comprehensive bee toxicity data, such as sublethal and synergistic effects on colonies, for all pesticides and methods of application (Hopwood et al. 2012). It is very important that growers are also educated on the proper use of these pesticides, which will prevent accidental losses of honey bees.
There is no definitive scientific evidence that neonicotinoids are the primary cause of pollinator declines. Given the current state of knowledge, banning neonicotinoids is a premature and disproportionate response to a complex issue. This issue requires holistic scientific inquiry and interpretation, and cooperation among stakeholders. Any changes must be based on science rather than opinion, current trends, or fear.
Related Links:
The American Entomologist article
UC Davis Preparing for the 2014 Student Debate
UC Davis Wins 2014 Student Debate Championship
- Author: Kathy Keatley Garvey
Carlson, to speak on avian (bird) malaria, was one of 20 presenters--five from each specialty section--selected by ESA officials to deliver a Premier Presentation. Her specialty section is Medical, Urban and Veterinary Entomology. A two to three-minute video featuring her and her work will be posted online following her presentation.
Carlson will discuss the work she completed at UC Davis under the tutelage of her major professor, medical entomologist Anthony Cornel, a member of the UC Davis Department of Entomology and Nematology faculty who is headquartered at the Kearney Agricultural Research and Extension Center, Parlier. While at UC Davis, Carlson was based in the lab of William Reisen, then a graduate student advisor with the Department of Entomology and Nematology and director of the Center for Vectorborne Diseases, School of Veterinary Medicine. Reisen, now retired, also served on her dissertation committee.
“I will present the avian malaria disease risk predictions for the endemic avian populations on Socorro Island, Mexico, and in the subarctic region of Alaska,” she said. “Using California-based vector competence studies as a guideline, I will discuss how vectors are structuring Plasmodium-host relationships by serving as both a compatibility filter and as an encounter filter. These are extremely important entomological considerations that must be included in a wildlife conservation and management plan, failure to neglect this component in disease risk assessments could result in the collapse of a fragile endemic avian population.”
While at UC Davis, Carlson received a number of honors, including the William Hazeltine Memorial Research Fellowship Awards for four years, 2011 to 2014; the Henry A. Jastro Shields Research Award, 2012 to 2014; and the UC Davis McBeth Memorial Scholarship, 2011 to 2012.
Her current goals are four-fold:
1. To continue conducting research in the field of human and animal disease.
2. To apply her knowledge in vector-borne diseases to help improve human, animal and ecosystem health.
3. To participate in collaborative research on naturally occurring human and animal disease,
4. To learn new molecular techniques that would aid in the identification of re-emerging and novel pathogens.
Carlson received her bachelor of science degree in zoology in 2006 from Colorado, State University and her master's degree in biology in 2008 from San Francisco State University.
- Author: Kathy Keatley Garvey
DAVIS--A team of five graduate students from the UC Davis Department of Entomology and Nematology will compete Tuesday, Nov. 18 in the Entomological Society of America's student debates at the 62nd annual meeting in Portland, Ore. Their topic: neonicotinoids.
The team, captained by Mohammad-Amir Aghaee of the Larry Godfrey lab, includes Jenny Carlson, Anthony Cornel lab; Margaret "Rei" Scampavia, Neal Williams/Edwin Lewis lab; Ralph Washington Jr., Steve Nadler lab; and Daniel Klittich, Michael Parrella lab.
Parrella, professor and chair of the department, serves as their advisor and coach.
UC Davis, which won the overall championship last year, will debate the Auburn (Alabama) University team, comprised of Olufemi Ajayi, Adekunle Adesanya, Julian Golec, Matt Burrows, Scott Clem, and alternate Zi Ye. Associate professor David Held advises the team.
Auburn will present information that neonicotinoids are causing the death of bees essential for pollinating our food crops, and that the use of neonicotinoids should end. UC Davis is the con team and will present evidence to the contrary.
The theme of the Entomology 2014 Debates is “Management Strategies: Solutions to Grand Challenges.”
In addition to neonics, other team topics are:
- The calls for the end of invasion biology are justified; this field should be replaced by the ecology of species redistribution. Washington State University vs. Louisiana State University.
- What is the single best tool to reduce malaria cases throughout the world? Florida A&M University vs. Kansas State University
The captain, Mohammad-Amir Aghaee, is heavily involved in ESA. He has been part of the debate and Linnean Games teams for four years. “Our debate team record has been 2-1 since 2011 and in 2013 we won 1st place for best team,” he said. He has participated in the student 10-minute paper competitions for four years, covering such topics as Lygus bug movements in bush beans, efficacy of Bacillus thuringiensis spp. galleriae against rice water weevil, and preliminary research on winter flooding effectiveness against rice water weevil. He won first place for his winter flood presentation in 2013.
Aghaee is a fifth year Ph.D. candidate working on rice water weevil (Lissorhoptrus oryzophilus) management in California rice. The majority of his dissertation research is dedicated toward developing alternative management options for growers. “I have examined the use of Bacillus thuringiensis spp. galleriae as a biopesticide for rice water weevil and explored the mechanisms of winter flooding rice fields as a cultural control against weevil larvae. I am currently examining the possible role of silicon augmentation as a means of increasing rice tolerance to weevil damage and the potential threat of Brown marmorated stinkbug (Halyomorpha halys) to California rice.
He has secondary interests in post-Renaissance European history and contemporary Middle Eastern politics. He explores some of these themes in his freshman seminar titled "Bugs, Germs, and Steel: A History of Entomology in Warfare" where he and his colleagues teach students how basic scientific research and ecology has influenced human conflicts and technological progress. Outside of entomology, his leisure activities include oil painting, language acquisition, and culinary specialization in Persian and Indo-Pakistani cuisines.
ESA president Frank Zalom, UC Davis distinguished professor of entomology, will preside over the 62nd annual meeting of the ESA, which meets Nov 16-19 in the Oregon Convention Center, Portland, Ore.
More than than 3,200 insect scientists have already registered, according to the ESA's communications program manager, Richard Levine. It is expected to be one of the largest entomology meetings in recent memory.
"The Northwest, with its natural beauty and location at the edge of the Pacific rim, is an ideal place to reflect on our Entomology 2014 theme: Grand Challenges Beyond Our Horizons," said Zalom, in an ESA news release "This year, ESA will be launching an effort to identify the most important challenges to which our discipline can make significant contributions.
More than 90 symposia are planned and will cover such topics as bed bugs, honey bees, monarch butterflies, ticks, native pollinators, pesticide regulations, biological control, integrated pest management, genetically-modified crops, invasive species, forestry, entomophagy, organic farming, insect-vectored diseases, and more. In addition, there will be 1,750 papers and posters, Levine reports.
Professor Diane Ullman will receive ESA's distinguished achievement award in teaching. This is the highest honor that the 7000-member ESA presents to its outstanding teachers.
Ullman earlier was named the recipient of the outstanding teaching award from the Pacific Branch of ESA. Ullman chaired the UC Davis Department of Entomology in 2004-2005, and served as an associate dean for undergraduate academic programs, College of Agricultural and Environmental Sciences. from 2005 to 2014. (See more information.)
Kelly Hamby, recipient of the John Henry Comstock Graduate Student Award from the Pacific Branch of ESA, will be honored, along with the other Comstock award winners from the other branches. (See more information)
Research entomologist James F. Campbell, who earned his doctoral in entomology from UC Davis in 1999, will receive a special recognition award. The award, sponsored by Syngenta Crop Protection, recognizes entomologists who are making significant contributions to agriculture. Campbell is a research entomologist with the Center for Grain and Animal Health Research Service of the USDA's Agricultural Research Service, Manhattan, Kansas. (See more information)
Nov. 5, 2012
The awards went to Jenny Carlson, avian malaria research, and Sandra "Sandy" Olkowski and Kelly Liebman, dengue research. Hazeltine's three sons, Craig of Scottsdale, Ariz; Jeff of Los Angeles; and Lee of Woodland recently visited the UC Davis campus to congratulate the winners and learn more about their research.
Carlson studies avian malaria with UC Davis associate professor/medical entomologist Anthony “Anton” Cornel, headquartered at the Kearney Agricultural Research and Extension Center, Parlier. Olkowski studies dengue with major professor/medical entomologist Thomas Scott. Liebman, also a graduate student of Thomas Scott's, now has her doctorate in entomology and is working at the Centers for Disease Control and Prevention in Atlanta, Ga.
Carlson received $2000; Olkowski, $1000' and Liebman, $580.
Carlson's research, titled “Culicine Vectorial Capacity and Its Implications for Transmission of Avian Malaria in Western United States,” involves host-feeding preferences, vector abundance and vectorial competence.
Carlson described malaria as “one of the most devastating diseases to humans” but it “also affects a wide range of other mammals, amphibians, reptiles and birds.”
Carlson, who received a Hazeltine Memorial Research Fellowship in 2010 and 2011, earned her bachelor of science degree in zoology from Colorado State University, Fort Collins, and her master's degree biology from San Francisco State University.
Olkowski's proposal is titled Association Between Preexisting DENV Immunity and Severe Disease Due to DENV-2 Infection in Iquitos, Peru.”
“Dengue fever is the most prevalent mosquito-borne viral disease in the world, with an estimated 50 to 100 million cases each year and 2.6 billion people at risk,“ Olkowski said. Illness is caused by infection with any of the four distinct viral serotypes (DENV-1, 2, 3 and 4).
“Severe severe disease was largely absent until introduction of a novel genotype of DENV-2 in 2010-11,” Olkowski said. Her research involves identifying “cohort participants who were infected with DENV-2 during the outbreak.”
“I will then use statistical models to evaluate the relationship between their serological history—by number of infections and serotype sequence—and clinical outcomes. Of particular interest are severe outcomes in persons with a single type of prior antibody, to determine if there was a spike in severity with second infection, as predicted by dengue epidemiology theory.”
Olkowski, who is seeking her doctorate in entomology with a major interest in medical entomology and public health, received a President's Undergraduate Fellowship in May 2011.
Liebman joined the Centers for Disease Control and Prevention in Atlanta following her exit seminar on “Implications of Heterogeneities in Mosquito and Human Populations on Dengue Virus Transmission in Iquitos, Peru.” She lived in Iquitos for a year while doing her research.
“Over the past three decades, dengue virus (DENV) as emerged as one of the most important arthropod-borne viral infections of humans, causing as many as 50 million infections worldwide each year,” Liebman wrote in her application. “The mosquito vector of DENV, Aedes aegypti, is exceedingly efficient because it feeds frequently and almost exclusively on humans.”
“An improved understanding of the distribution of the bites among people in Iquitos will allow me to estimate differential risk of infection based on exposure to mosquito bites and significantly improve understanding of local DENV transmission dynamics,” she wrote.
Liebman, who received Hazeltine Memorial Fellowship Awards in 2009 and 2011, obtained her her master's degree in public health from Yale University and her bachelor's degree in biology from the University of Michigan, Ann Arbor.
The Hazeltine Memorial Fellowship Awards memorialize William “Bill” Hazeltine (1926-1994), who managed the Lake County Mosquito Abatement District from 1961-64 and the Butte County Mosquito Abatement District from 1966-1992. He was an ardent supporter of the judicious use of public health pesticides to protect public health. He continued work on related projects until his death in 1994.
Hazeltine studied entomology in the UC Berkeley graduate program from 1950-53, and received his doctorate in entomology from Purdue University in 1962.
He maintained close ties with UC Davis entomologists. UC Davis medical entomologist Bruce Eldridge eulogized him at the 2005 American Mosquito Control Association conference “as a man who made a difference.” His talk, illustrated with photos, was published in the 2006 edition of the Journal of the American Mosquito Control Association. (See PDF)
"He was a medical entomologist who had a varied career in the field of mosquito biology and control, but he will forever be remembered as a man who fought in the trenches of the pesticide controversy from 1960 until the end of his life, and who made the safe and efficient use of pesticides in public health a personal crusade," Eldridge said.
Eldridge noted that Hazeltine "was an advocate for the use of mosquito control to protect people from mosquitoes and the disease agents they transmit, and he believed chemical control to be a necessary part of the means to accomplish this. He also considered himself an environmentalist, and billed himself as such on his business cards and on his signature block. He had a vast knowledge of pesticides and pesticide legislation, and a strong belief in the scientific basis for public policy issues related to the safe and effective use of pesticides. Because the federal Endangered Species Act influenced mosquito control, he became an authority on this as well."
Eldridge described him as "an effective manager and leader at Butte County. Those who took the trouble to get to know him developed a strong allegiance to him. Most appreciated his absolute honesty and fairness. Not only was Bill honest to a fault, he expected it of people who work for him as well."
Hazeltine, born Sept. 4, 1926 in San Jose, was the youngest of six children born to Karl Snyder Hazeltine and Rachel Josephine Crawford Hazeltine. Karl, a graduate of the University of California, served on the faculty of San Jose State University, where he taught agricultural and natural science. Rachel, a graduate of San Jose State, was a teacher.
Previous recipients:
2011: Brittany Nelms Mills, Kelly Liebman and Jenny Carlson (see story)
2010: Tara Thiemann and Jenny Carlson (see story)
2009: Kelly Liebman and Wei Xu (See story)
2008: Ashley Horton and Tara Thiemann (See story)
2007: Lisa Reimer and Jacklyn Wong (See story)
2006: Christopher Barker and Tania Morgan (See story)
2005: Nicole Mans
2004: Sharon Minnick
2003: Hannah Burrack
2002: Holly Ganz and Andradi Villalobos
2001: Laura Goddard and Linda Styer
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
