- Author: Kathy Keatley Garvey
(Editor's Note: An update: The results of the CDFA analysis have been announced. The maternal lineage of the problematic colony in Concord was European. "Therefore, if that queen's daughters were acting in a very Africanized manner, it might have been because she mated with Africanized drones in the area," said Extension apiculturist emeritus Eric Mussen, "or because there are a number of drones from European cantankerous colonies around the area. The paternity tests were not run.")
It's all the buzz.)
For the past several days, journalists have sought out UC Davis experts Extension apiculturist Elina Niño and Extension apiculturist (emeritus) Eric Mussen to weigh in on the recent defensive bee incident in Concord.
The three-day incident began Friday, May 13, and primarily ended on Sunday, when many of the bees were destroyed. What happened: A beekeeper on Hitchcock Road was moving his two hives to make way for landscaping in his yard. He moved the first hive successfully, but the bees in the second hive turned defensive, killing two dogs, attacking a mail carrier, and targeting numerous passersby.
DNA tests are underway to see if the bees are Africanized. “Their behavior is very suggestive that they could be Africanized,” Mussen said.
Niño, who joined the UC Davis Department of Entomology and Nematology in September 2014, replacing Mussen, was interviewed by the Associated Press, San Francisco and Kathy Park of KXTV Channel 10 and Tom Jensen of KCRA Channel 3. More interviews are pending.
Mussen, who completed a 38-year career in 2014 and now serves as emeritus, was quoted in the San Francisco Chronicle and in other news media.
Niño told KCRA "Africanized honey bees tend to be more defensive, they amount a stronger defensive response. First of all, we don't like to call them killer bees. That's definitely not what they're there for. They're not coming at you for no reason."
Mussen told the San Francisco Chronicle that attempts to avoid the bees may have actually made things worse. Waving arms and swatting motions can provoke bees to sting — and then the stings themselves act as markers for other bees to target, he said.
Africanized bees are a hybrid of African honey bees and European/Western honey bees. In the 1950s, Brazilian scientists exported bees from South Africa to improve breeding stock and increase honey production. However the bees escaped quarantine and began mating with European honey bees. Since they they have spread throughout South and Central America and arrived in North America in 1985. Africanized bees expanded into southern California in 1994.
In appearance, Africanized bees and European honey bees look alike and cannot be distinguished except through DNA tests, Niño and Mussen said.
Mussen says that we have three ways to try to differentiate between Africanized honey bees (AHBs) and European honey bees (EHBs):
1. Mitochondrial DNA – The California Department of Food and Agricuture (CDFA) still conducts this type of testing once a year to clear the California Bee Breeders for queen exports into Canada. CDFA also uses this criterion as "the one" for declaring Africanization. However, its value in predicting temperament of the colony population is not particularly reliable.
2. Isozymes - the amino acid composition of certain enzymes differs between the two races
3. Morphometrics - computer matching of current sample specimens to verified AHB and EHB samples using measurements of various anatomical features. Hybrids are problematic.
"That type of bee was found around southern California and as far north as not too far from Angles Camp (Calaveras County)," Mussen mentioned. "Further north, they found only specimens with one or two traits, but not all three. That even occurred just into southern Oregon."
“Yes, EHB colonies can behave in that nasty manner, but I think it is more likely that AHBs are involved,” Mussen says. He recalled that twice in the 1980s, swarms of bees from South America accompanied shipments of raw sugar cane into the C&H sugar refinery in Crockett (Contra Costa County). We know the first one got away. They think they got the second one, but could not find the queen in either case. Since that time, there have been increasing complaints of 'hot' bees from that area, south to Castro Valley (Alameda County).”
Assistant professor Brian Johnson of the UC Davis Department of Entomology and Nematology, is doing research on genetic dispersion of AHBs around the state. He is collecting and freezing samples.
- Author: Kathy Keatley Garvey
Yes, they can.
And now UC Davis ecologist Richard “Rick” Karban's research is “talking” in TED-Ed Original Lessons and drawing international attention from thousands of teachers, their students and other Internet viewers.
Karban's work on plant communication is featured in an interactive lesson plan where "words and ideas of educators are brought to life by professional animators.” Teachers can customize the lesson plan to engage their students.
Plants can eavesdrop, sense danger in the environment, and can distinguish friend from foe, says Karban, a professor in the UC Davis Department of Entomology and Nematology, who recently published a 250-page comprehensive book, Plant Sensing and Communication (University of Chicago Press), hailed as a landmark in its field.
A plant under a predatory attack will emit volatile chemical cues, enabling its neighboring plants to adjust their defenses to better protect themselves.
Nearly 130,000 have accessed the lessons, with nearly 2000 questions answered. In the TED-ED lessons, teachers can interact with their students, quizzing them on:
- What are some characteristics of the language of plants?
- Why do plants communicate? What advantages might they get from communicating that increase their chances of survival and reproduction?
- In what ways are communication systems between plants similar to communication systems between animals? In what ways are they different?
The creators of the plant communication lesson are Karban, educator; Yukai Du, director; Angus MacRae, composer; Eleanor Nelson, script editor; and Jiaqi Wang, animator.
Karban has researched plant communication in sagebrush (Artemisia tridentata) on the east side of the Sierra since 1995. His groundbreaking research on plant communication among kin, published in February 2013 in the Proceedings of the Royal Society B: Biological Sciences, drew international attention. In that study, Karban and his co-researchers found that kin have distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors.”
“Plants responded more effectively to volatile cues from close relatives than from distant relatives in all four experiments and communication reduced levels of leaf damage experienced over the three growing seasons,” they wrote.
In other words, if you're a sagebrush and your nearby kin is being eaten by a grasshopper, deer, jackrabbit, caterpillar or other predator, communication is more effective if you're closely related. Through volatile cues, your kin will inform you of the danger so you can adjust your defenses.
Karban likened this kind of plant communication to eavesdropping.” Plants “hear” the volatile cues of their neighbors as predators damage them.
The most basic form of communication? When a plant is being shaded, it senses the diminished light quality caused by a competitor and responds by moving away, Karban says.
What are 10 things to know about plant sensing and communication? According to Karban:
- Plants sense their environments and respond.
- Although they lack central nervous systems, they process information and appear to "behave intelligently."
- They sense the position of competitors and "forage" for light.
- They sense the availability of water and nutrients in the soil and "forage" for these resources.
- Their decisions are influenced by past experiences, akin to memory.
- The respond to reliable cues that predict future events, allowing them to "anticipate."
- Plants respond differently to cues that they themselves produce, allowing them to distinguish self from non-self.
- They respond differently to close relatives and strangers.
- Plants that are prevented from sensing or responding experience reduced fitness.
- By understanding the "language" of plant responses, we can grow healthier and more productive plants.
The most basic form of communication? When a plant is being shaded, it senses the diminished light quality caused by a competitor and responds by moving away, Karban says.
Karban is a fellow of the American Association for the Advancement of Science (AAAS) and has published more than 100 journal articles and now, three books.
Karban is featured in the Dec. 23-30, 2013 edition of The New Yorker in Michael Pollan's piece, “The Intelligent Plant: Scientists Debate a New Way of Understanding Plants."
Related Link:
Rick Karban: Kin Recognition Affects Plant Communication and Defense
- Author: Kathy Keatley Garvey
Male Aedes aegypti mosquitoes infected with a bacterium, Wolbachia pipientis, are being released in Clovis, Fresno County, where this mosquito was discovered in June 2013. Although this mosquito is now found in California, there has been no locally transmitted case of the Zika virus in the state.
The project, to determine dispersal and survival, began Monday, May 10.
“The daytime-biting mosquito, which feeds predominantly on humans, has spread to at least seven counties since its discovery in Clovis,” said Cornel, a mosquito researcher and faculty member with the UC Davis Department of Entomology and Nematology and the UC Kearney Agricultural Research and Extension Center, Parlier.
“The biting nuisance and potential of the mosquito Aedes aegypti to transmit Zika, Chikungunya and dengue viruses in California is cause for concern,” he said. “Efforts to curb its spread and reduce populations have not been very effective. Control efforts have included educating the public to remove standing water (source reduction) insecticide barrier sprays and bacterial larviciding.”
The collaborative effort involves Steve Mulligan, director of the Consolidated Mosquito Abatement District, based in Fresno County; Stephen Dobson of the University of Kentucky; MosquitoMate Inc, (mosquitomate.com); and UC Davis. The researchers will evaluate the population suppressive ability of the novel sterile insect technique, which is part of a comprehensive vector management approach.
Only Aedes aegypti is targeted. “When the Wolbachia-infected male mosquito mates with non-infected females, the result is “cytoplasmic incompatibility, which causes the female to lay infertile eggs that will not hatch,” Cornel explained.
“This approach requires the release of tens of thousands of Wolbachia-infected males into residential neighborhoods where this mosquito is a nuisance,” the medical entomologist said. “Releasing large numbers of males increases the chance that an introduced male will mate with the native females.”
Although residents will notice increased numbers of male mosquitoes, male mosquitoes do not bite and cannot transmit disease. Both U.S,federal and State regulatory agencies have approved the technique for evaluation of effectiveness.
“This sterile insect technique was evaluated in 2015 in Los Angeles to suppress another invasive mosquito, Aedes albopictus,” Cornel said, adding that the results from that trial look promising.
The Zika virus, now spreading throughout the Western hemisphere, was first identified in Uganda in 1947 in rhesus monkeys, according to the World Health Organization. It was subsequently identified in humans in 1952 in Uganda and the United Republic of Tanzania. Outbreaks of Zika virus disease have been recorded in Africa, the Americas, Asia and the Pacific.
Despite the mosquito's invasion into new areas of the United States, there are no reported cases of locally transmitted Zika virus in California or in the contiguous United States, according to the Centers for Disease Control and Prevention. The cases have all involved travelers returning home from countries plagued with disease outbreaks.
“We can't predict how far this mosquito will spread in California,” said Cornel, noting that its range has expanded “south of Fresno to San Diego. The farthest site north is Madera in the Central Valley, but it's also been found in the more coastal area of Menlo Park in San Mateo.”
It's troubling that the mosquito is becoming more and more resistant to pesticides, said Cornel, who collects, rears and researches mosquitoes from all over the world, including the United States, Mali, Cameroon, Comoros, Tanzania, South Africa and Brazil.
“We have found that Aedes aegypti have insecticide resistance genes which likely explains why the use of ultra-low volume and barrier spray applications for control have not worked as well as expected.”
- Author: Kathy Keatley Garvey
Co-authoring the first-place poster were mentors Hillary Sardinas, alumna of the Claire Kremen lab, UC Berkeley, and now with the Xerces Society for Invertebrate Conservation; and UC Berkeley Professors Nick Mills and Claire Kremen.
The Bee Symposium was sponsored by the UC Davis Honey and Pollination Center, directed by Amina Harris, and the UC Davis Department of Entomology and Nematology, chaired by Steve Nadler.
Associate professor/Chancellor's Fellow Neal Williams of the UC Davis Department of Entomology and Nematology announced the four winners, all from UC Berkeley or UC Davis. He serves as the co-faculty director of the Honey and Pollination Center.
Second place of $750 went to UC Davis graduate student W. Cameron Jasper for his poster, "Investigating Potential Synergistic Effects of Chronic Exposure to Amitraz and Multiple Pesticides on Honey Bee (Apis mellifera) Survivorship." Jasper studies with major professor and Extension apiculturist Elina Lastro Niño, UC Davis Department of Entomology and Nematology. Niño and K. Grey co-authored the poster.
Third place of $500 went to UC Davis graduate student Britney Goodrich for her poster on "Honey Bee Health: Economic Implications for Beekeepers in Almond Pollination." She studies with major professor Rachael Goodhue of the UC Davis Agricultural and Resource Economics, co-author of the poster.
Fourth place of $250 went to UC Davis graduate student John Mola for his poster on "Fine Scale Population Genetics and Movement Ecology of the Yellow-Faced Bumble Bee (Bombus vosnesenkii). His poster co-authors: faculty members Neal Williams, UC Davis Department of Entomology and Nematology; and Michael Miller and Sean O'Rourke of the Department of Animal Science and Graduate Group in Ecology.
The Honey and Pollination Center funded the awards, with the program underwritten by Springcreek Foundation; Natural American Foods and the American Beekeeping Federation.
A trio of entomologists judged the posters: Dennis vanEnglesdorp, professor of entomology at the University of Maryland, College Park; Robbin Thorp, distinguished emeritus professor of entomology at UC Davis; and Quinn McFrederick, assistant professor of entomology, UC Riverside.
Yves Le Conte, director of the French National Institute for Agricultural Research, Paris, keynoted the symposium, launching the daylong conference that took place in the UC Davis Conference Center. VanEnglesdorp delivered the keynote speech in the afternoon.
Coordinating the poster competition was program representative Christine Casey of the UC Davis Department of Entomology and Nematology, staff director of the Häagen-Dazs Honey Bee Haven.
The competition was open to graduate students from any related department--UC Davis, UC Berkeley, California State University, Sacramento, and beyond, Casey said.
Last year's winners were all from the UC Davis Department of Entomology and Nematology:
- First Place: Margaret "Rei" Scampavia, "Farming Practices Affect Nest Site Selection of Native Ground Nesting Bees"
- Second Place: Jennifer VanWyk, "Wet Meadow Restoration Buffers the Impact of Climate Change: Pollinator Resilience during the California Drought"
- Third Place: Leslie Saul-Gershenz, "Native Bee Parasite Shows Multitrait, Host-Specific Variation and Local Adaptation"
- Author: Kathy Keatley Garvey
The researchers found that a chemical inhibitor of a soluble epoxide hydrolase may be a new, innovative tool to control depression, a severe and chronic psychiatric disease that affects 350 million persons worldwide.
Soluble epoxide hydrolase, or sEH, is emerging as a therapeutic target that acts on a number of inflammatory or inflammation-linked diseases, said NIEHS grantee Bruce Hammock, who holds a joint appointment in the UC Davis Department of Entomology and Nematology, and the UC Davis Comprehensive Cancer Center.
“The research in animal models of depression suggests that sEH plays a key role in modulating inflammation, which is involved in depression,” Hammock said. “Inhibitors of sEH protect natural lipids in the brain that reduce inflammation, and neuropathic pain. Thus, these inhibitors could be potential therapeutic drugs for depression.”
NIEHS singled out the depression research as one of its four top papers of the month. It headlined the work “Anti-Inflammatory Chemical May Offer New Tool for Depression Treatment,” in its May newsletter.
“Researchers found that the sEH inhibitor, 1-trifluoromethoxyphenyl-3-(1-propionylpiperidine-4-yl)urea (TPPU), displayed rapid antidepressant effects in mice,” according to the NIEHS summary. “Researchers observed mice for depression-like behavior after repeated social stress. They found that administering TPPU reduced depression-like behaviors. Inhibiting sEH in the mice also produced resilience to the repeated stress.”
“The researchers also observed higher levels of sEH expression in key brain regions of the chronically stressed mice than in mice not subject to repeated stress,” NIEHS wrote. “They then examined postmortem human brain samples from patients with psychiatric diseases, including depression.
The work, published March 14 in the journal Proceedings of the National Academy of Sciences, drew international attention.
Other authors on the paper are Christophe Morisseau, Karen Wagner and Jun Yang, UC Davis; and Qian Ren, Min Ma, Tamaki Ishima, Ji-chun Zhang, Chun Yang, Wei Yao, Chao Dong, and Mei Han, Chiba University.