- (Public Value) UCANR: Protecting California's natural resources
The news stories and social media comments about the Asian giant hornet detected last year in British Columbia and Washington state and labeled “the murder hornet,” are drawing the ire of entomologists throughout the world.
And well they should.
UC Davis wasp expert and researcher Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology, UC Davis Department of Entomology and Nematology, called the name "ridiculous" and said "it's no more likely to sting and kill a human than a honey bee." (See Bug Squad blog)
Lynn Kimsey, director of the Bohart Museum of Entomology, UC Davis, shows a queen Asian giant hornet, one of 20 in the Bohart's global collection. The largest in the collection, it is about an inch and a half long, she said.
Kimsey, a two-term past president of the International Society of Hymenopterists, told us yesterday that “Actually it's less likely, as honey bee venom packs quite a punch and it is exclusively designed to defend against vertebrates."
“The colony everyone is hyperventilating over was actually found on Vancouver Island, British Columbia, last September when it was destroyed and then a single, dead hornet was found in December in Blaine, Wash.,” Kimsey said. “There is no evidence that there are any more hornets in the vicinity of Vancouver or anywhere else on the West Coast.”
A colony of the Asian giant hornet (AGH), Vespa mandarinia, was found and destroyed Sept. 18, 2019 in Nanaimo, Vancouver Island, and the single dead hornet was found Dec. 8, 2019 in Blaine.
These were the first detections of this species in North America, and no, the so-called "murder hornets" are not out to get us. They're not out to kill you. They're not taking over the world. (Expect some upcoming horror movies, though!)
Twenty Asian giant hornet (AGH) specimens are housed in the Bohart Museum of Entomology, home of a global collection of nearly 8 million species. The largest AGH, a queen, measures about an inch and a half long, Kimsey said. She's never seen any larger than that.
Meanwhile, entomologists are bemoaning the name, "murder hornet" and the sensationalism and fear-mongering ensuing. Apparently the name originated with a Japanese researcher; out of the translation came "murder hornet."
“It's a bloody dumpster fire,” said entomology advocate, traveler and photographer Stephane De Greef, administrator of a newly created Facebook page, “Is This a Murder Hornet?”
“Some poorly-worded media reports about Asian giant hornets have triggered a veritable avalanche of nonsense online, but I can help set the record straight, wrote senior museum scientist and hymenopterist Douglas Yanega of UC Riverside Entomology Research Museum.
“One colony was found and exterminated in Nanaimo on Vancouver Island in September of 2019, with a few sightings associated,” Yanega wrote. “One wasp believed to be from that colony was found--dead--on the U.S. side of the border near Nanaimo in December. Right now, all the authorities are doing is asking people to keep their eyes peeled JUST IN CASE there were queens that escaped the destruction of the Nanaimo nest, and established their own nests nearby. I was one of the authorities brought in to consult on this case, and to my knowledge there have not been any sightings in 2020 that would suggest the eradication attempt was unsuccessful. Put bluntly, as far as we know, there are no Asian giant hornets alive in either the U.S. or Canada as of 2020, and if there are, then they would be in the immediate vicinity of Vancouver Island (about a 50 mile radius or so).”
Want to know more about them? Read the fact sheet published by Washington State University Extension. It's the work of the husband-wife team of Susan Cobey, bee breeder-geneticist and Timothy Lawrence, county director of Island County Extension (both formerly of UC Davis), and also Mike Jensen, county director of Pend Oreille. (See https://bit.ly/2SA3TxS)
“It is critical that we identify, trap, and attempt to eliminate this new pest before it becomes established and widespread,” they wrote. “Attempts to contain the spread and eradication of this invasive insect will be most effective in trapping queens during early spring before their nests become established. Finding the nests can be a bit of a challenge. Their nests are typically in the ground though they can also be found under overhangs and within wall voids. The AGH is a strong flier and often will fly up and away and have an extensive flight range. Thus tracking can be difficult.”
They advise residents to “proceed with extreme caution and contact WSDA immediately. Do not try to exterminate the nest yourself.”
The sensationalism on the media is a concern, said Lawrence, "but...we need to find out just how extensive this infestation is."
Facebook users are posting images of so-called Asian giant hornets that are actually such species as cicada killers, European hornets, southern yellow jacket queens, sawflies, hoverflies, a beetle, and even a moth.
“Yes, it is possible this species could establish,” wrote Sloan Tomlinson, a parasitoid wasp specialist and educator. “Has it yet? No. Until concrete evidence is presented about any further establishment by this species, it's simply conjecture. Additionally, even IF this species is established, their infamy is overhyped and sensationalized. In Japan they do indeed kill around 30 people a year. Around 40 people are killed annually in the US by domestic dogs.”
Doctoral candidate and researcher Ellie Field of Iowa State University wrote on Facebook that “the murder hornet articles are making the rounds quickly and they seem to be doing more harm than good. Yes, it is awesome to track insect populations (particularly staying watchful for non-native and potentially invasive species). But no, the Asian giant hornet (Vespa mandarinia) is not going to destroy America. The one nest and individual that was found around Vancouver last year was destroyed, and this doesn't indicate any establishment. Introduction events happen all the time, all across the world! That region should continue to keep a watchful eye, but for everyone else this is not going to be relevant. There is no invasion, just a small possibility that some may have overwintered in that area.”
Those unsure about insect identification can email an image to Lynn Kimsey at email@example.com or contact the Entomological Society of America at https://www.entsoc.org/ or https://bit.ly/2W2jRmi.
Meanwhile, they're trying to douse the "bloody dumpster fires."
(Update: UC Davis distinguished professor Walter Leal, who studied and worked in Japan, asked a Japanese friend today about the origin of "murder hornet": The Asian giant hornet, Vespa mandarinia, is called “Kiiro Suzume Bachi (キイロスズメバチ)” in Japanese. It injects its venoms, sometimes inducing severe anaphylaxis. The article in BBC introduced Asian giant hornet, Vespa mandarinia as “murder hornet” is at https://www.bbc.com/news/52533
- Author: Royce Larsen
Oaks and Oak Woodlands Explained
“Natural History of the Central Coast Bioregion” (adapted from Gregory Ira's announcement: https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=31003) The publication's lead author, Bill Tietje (Environmental Science, Policy, and Management, University of California, Berkeley), with co-authors William Preston (Geographer Emeritus, Cal Poly, San Luis Obispo) and Anne Polyakov (University of California, Berkeley; currently a Masters Student, University of Washington), created a highly readable and engaging description of the Central Coast Bioregion. “We strived to write in everyday English and create a scientifically accurate and engaging presentation.” The authors succeeded on both counts by use of plain language, common plant and animal names, and short paragraphs supported with over 65 high-quality photographs, four maps, two diagrams, ten vignettes, and 70 references for further reading.
The Central Coast Bioregion, an area between the Pacific Ocean and the San Joaquin Valley, and extending from Monterrey south to Santa Barbara, is home to wildly popular and lesser known destinations. Well known areas include the Big Sur Coast, the estuaries at Elkhorn Slough and Morro Bay, and Monterrey Bay Aquarium. Some of the hidden gems are Pinnacles National Park, Santa Barbara Botanic Garden, and the Gardens of the La Purisima Mission. Together, the authors describe the origins and present composition of the region's environments: “Across the region's 15,000 square miles, physical, and biological processes, combined with time and human actions, have resulted in a broad range of ecosystems, each harboring distinct assemblages of plants and animals.” The publication uses engaging vignettes to highlight local conservationists, regional wildlife, historical and contemporary restoration efforts, and interesting places to explore. It begins with a brief history of the region, providing context to descriptions of subsequent environmental and land-use changes, a reminder to readers that while the future of the central coast is uncertain it will be shaped by our actions. You can find the publication at:https://anrcatalog.ucanr.edu/pdf/8597.pdf
Sharing Oak Woodland Research through a Popular Website (adapted from Devii Rao, Bill Tietje,Luke Macaulay, and Judi Young) Since its creation in 1995, the University of California Oak Woodland Management website has been a valuable educational resource. Based on Google Analytics data from 2011 to 2017, the website receives an average of 45,000 users annually. It is a repository of nearly 30 years of research and outreach data on the ecology, management, and conservation of California's 8 million acres of oak woodlands.
Recent staff retirements and changes in website standards created a need for an update and redesign. To accomplish this, the University of California Cooperative Extension received a Renewable Resources Extension Act Capacity Grant that allowed us to reformat the website for mobile devices; make the website more functional and visually appealing; add some of the latest research; and promote the website to groups who have not historically used it, in particular, the ranching community.
To increase user friendliness, we developed links at the top of the home page for the three primary target audiences: homeowners, land-use planners, and ranchers. On the home page, we also highlighted five topics that receive the most hits: species identification and ecology; oak regeneration and restoration; economic and ecological values of woodland stands; threats to oak woodlands; and woodland wildlife. The new website, now called UC Oaks, went live in June of 2020.
The new flexible website design will allow us to continuously meet the needs of our clientele. With its new look and expanded reach, we hope that the website will be a one-stop-shop for everything people need to know about oak woodland conservation and management. https://oaks.cnr.berkeley.edu/
This Webinar will be tomorrow, March 18, 2020
Tune In and Register below
Dr. Ben Faber will discuss plant growth regulators (PGRs), a powerful tool available for increasing fruit size and yield in an existing avocado orchard. Gibberellic acid (GA3) was registered for use on California avocados in March 2018 to improve fruit productivity. The handling, timing and application rate are critical and the reasons will be included in this discussion. Approval of one hour of DPR continuing education unit is pending.
Avocados in some parts of coastal California have been blooming. Some of them got hit by the cold weather in the first part of February. In the coldest areas there was a little bit of new leaf damage, but this has been minimal.
Some browning of some flowers and stems (pedicels - the little stalks the connect the flowers to the larger raceme/panicle) may have occurred, but I haven't heard of major flower damage.
It's early days for flowering, though, and most ‘Hass' trees are not very far along, but seem like they area about to burst. A recent visit on a 40 acre farm in Saticoy had trees in a whole range of stages, some with no flowers pushing, some with panicles just starting to open individual flowers and many trees on their north sides' completely quiet. Many are still just pushing into the cauliflower stage,
which is the ideal time is for applying Pro-Gibb to improve fruit set in healthy orchards.
Application time is when 50% of the trees in the block have 50% of their bloom in the cauliflower stage. This is a judgment call when there can be such huge variation in bloom across and orchard. It's going to be a best estimate call for when to do the application. As usual with a new technology/practice don't apply to the whole orchard so that you can see whether the application is warranted.
For a more detailed discussion of gibb application, read Carol Lovatt's article:
Araujia sericifera, cruel vine, moth plant, bladderflower is an escaped ornamental that has become an invasive weed in California. Yes, a pretty vine brought into the garden – “poor man's stephanotis” - and it's gotten out of the garden into southern California. It's in the hills, in abandoned orchards, on backyard fences and when it gets into a lemon tree, it takes some effort to remove it before the seeds spread to other trees and beyond.
Bladderflower is a perennial vine that is very vigorous where it gets summer water. It is a common weed in citrus groves, where it would enshroud & smother entire trees if not controlled. Stems are tough and ropy, leaves thick & slightly spongy. Sap is milky white, moderately poisonous & causes skin irritation. It flowers Aug-Oct and the seed pods are obvious later in the fall. The flowers have a pleasant fragrance like jasmine. The reason for gardeners planting it. Plus it grows fast in our environment.
The plump pods produce copious seeds when ripe. The fruit splits down one side and turns itself inside out. The numerous, loosely attached seeds parachute away on silky hairs, dispersed by the wind – on to the next tree or fence.
So the vine is entrained in the tree canopy so you cant spray an herbicide. To get rid of it, it's important to get down to the base of the tree and cut it out at ground level, removing as much of the root as possible. It still can regenerate, so it will be necessary to monitor the site, removing new growth as it might happen. Be sure to use hand protection because many people are allergic to the sap. Just cutting the vine at its base is sufficient to kill it. Removing the rest of the vine is necessary if there are pods, in order to prevent them going to seed.
The upside of the plant aside from the fragrant flowers is that it is an alternative food source for monarch butterfly caterpillars.
Calfflora shows cruel vine spread mostly along the coast south of San Luis Obispo, but it has the potential to spread thoguhout much of California. Currently, in the US, it is only found in California and Georgia. It is in New Zealand and Australia.
USDA Description of Plant as attachment below:
First, remember that the desire to avoid any kind of an interaction is mutual. Rattlesnakes are an important part of the ecosystem, feeding on rodents, birds, and other small animals.Snake season in Southern California runs from April through October, but the warmer the weather, the more the reptiles are likely to be out and about. Rattlesnakes are California's only native venomous snake, with some adults reaching up to 6 feet long. According to the California Poison Control Center notes, rattlesnakes account for more than 800 bites each year, with one to two deaths. About 25 percent of the bites are "dry," meaning no venom was injected, but the bites still require medical treatment.There are nine species live in various areas of the state and their size can vary.
According to the University of California Integrated Pest Management Guidelines(2014),the most widespread rattlesnake in California is the western rattlesnake (Crotalus oreganus), found from the northern part of the state as far south as Santa Barbara County and from sea level to 7,000 feet. Two closely related species (C. helleri and C. lutosus) are found in coastal Southern California and in the northern Sierra Nevada, respectively. The sidewinder (C. cerastes) is the smallest rattlesnake and is so named because of its peculiar method of sideways locomotion. The sidewinder is sometimes called the horned rattler because of the hornlike scales above its eyes. It is most commonly found in sandy desert areas from below sea level to 6,000 feet. The Mohave rattlesnake (C. scutulatus) ranges across the desert and foothills of southeastern California from sea level to higher elevations. The southwestern speckled rattlesnake (C. mitchellii) ranges from Baja California northward across much of the Colorado, Mojave, and Sonoran Deserts, overlapping with the red diamond rattlesnake (C. ruber) in western parts of its range and the sidewinder farther east. The Panamint rattlesnake (C. stephensi) is closely related but has a more northerly distribution in the inland desert regions of Southern California. The red diamond rattlesnake is found in Baja California and in southwestern California south of Los Angeles. The western diamond-backed rattlesnake (C. atrox) is seldom seen in California but occurs in the extreme southeastern part of the state in desert regions.
Of the nine species of rattlesnakes in this region, the Western Diamondback rattlesnake is probably the most dangerous because of its size and aggressive nature. State experts say the Diamondback can be found primarily in Imperial, Riverside and San Bernardino counties. Most trees crops that are found in this county that are at risk for hosting these snakes are avocados, citrus and dates.
This vertebrate pest can cause a threat to workers conducting routine agriculture cultural practices such as irrigating, fertilizing, and harvesting. In the deserts of Riverside and Imperial county where the laborious date palms are grown, rattle snakes can cause a threat to harvesters if orchard vegetation is left uncontrolled. The snakes are also attracted to water, so irrigators can run the risk of coming into contact with the snakes.
Biology and Behavior
Rattlesnakes are thick-bodied snakes with keeled (ridged) scales in a variety of colors and patterns. The National Wildlife Federation reported that rattlesnakes typically live for 10 to 25 years.
Most species are patterned with dark diamonds, rhombuses or hexagons on a lighter background. Rattlesnakes are ovoviviparous, which means that eggs incubate inside the mother's body. Babies are born live, encased in a thin membrane that they puncture after being born.
They are among the group of snakes called pit vipers because of the small pits on each side of the head between the eye and nostril. These pits are temperature-sensitive structures that assist the snake in finding prey, even in complete darkness. The tongue is also used to detect the scent of prey. Rattlesnakes have a specialized venom delivery system. Venom is produced in glands behind the eyes and then flows through ducts to the hollow fangs. Normally the fangs fold back against the roof of the mouth and when a snake strikes, the fangs pivot forward to inject venom.(Kardong and Bels, 1998).
The California Department of Fish and Wildlife recommends being alert and also having a sense of where a rattlesnake could be at a particular time of day. After a cold night, the snakes will try to raise their body temperatures by laying out in the sun around mid-morning. To prevent overheating during the day, they may be more active at dusk, dawn and nighttime hours.Though they are not nocturnal, in the hot summer months they may be more active at night.
The nine species of rattlesnakes found in California are not considered endangered or threatened. California Department of Fish and Wildlife Code classifies rattlesnakes as native reptiles. California residents can take most rattlesnake species on private lands in any legal manner without a license or permit, although a bag limit of two still applies. Additionally, the red diamond rattlesnake (C. ruber) is prohibited from being taken or killed by state wildlife regulation.
Most rattlesnakes seek cover in crevices of rocks, under surface objects, beneath dense vegetation and in rodent burrows, so eliminating potential shelter is critical. Adults eat live prey, primarily rodents; the young consume mostly lizards and young rodent.Controlling the vermin population in your orchard ia an important factor as the rodent borrows can become a snake's new homes. Weed management in orchards are critical during the warmer months. The vegetation can be a habitat for snakes.In addition,pruning or removing old trees from the orchard, proper disposal of the wood is important. Stacking or saving the wood in piles create a habitat for the rattlesnakes.
Structures for farming operations can vary in size and age. Chemical sheds, equipment garages, machinery shops are infamous to hosting snakes. In summer, rattlesnakes may be attracted to cool and/or damp places, such as beneath buildings. Sealing all cracks and other openings greater than 1/4inch can prevent them from entering. Gaps beneath doors are often large enough to permit snakes to enter, especially young ones.
According to the University of California Integrated Pest Management Guidelines(2014),rattlesnakes add to the diversity of our wildlife and are important members of our ecosystem. They can reduce the number of disease carrying rodents and other pest species. In general, they should be left alone, whenever possible, especially in wildland areas. Nonvenomous snakes, such as gardener snakes should also be left alone wherever found.
California Department of fish and Wildlife. https://www.wildlife.ca.gov/Keep-Me-Wild/Rattlesnakes. Accessed 20 June 2019.
California Poison Control. https://calpoison.org/topics/rattlesnakes. Accessed 20 June 2019.
Kardong, K. V. and Bels, V. L. 1998. Rattlesnake strike behavior: kinematics. Journal of Experimental Biology, 201(6), 837-850.
National Wildlife Federation. https://www.nwf.org/Educational-Resources/Wildlife-Guide/Reptiles/Rattlesnakes. Accessed 20 June 2019.
Salmon, T. P., D. A. Whisson, and R. E. Marsh. 2006. Wildlife Pest Control Around Gardens and Homes. 2nd ed. Oakland: Univ. Calif. Agric. Nat. Res. Publ. 21385.
Todd, B., T.P. Salmon, D.A. Whisson and R.E. Marsh.University of California Integrated Pest Management Guidelines http://ipm.ucanr.edu/PMG/PESTNOTES/pn74119.html. Accessed 20 June 2019.
Walter, F. G., U. Stolz, F. Shirazi, J. McNally. 2009. Epidemiology of severe and fatal rattlesnake bites. Philadelphia: American Association of Poison Control Centers' Annual Reports. Clin. Toxicol. 47:663-669.