It's always a good day when you encounter a dragonfly on Main Street USA.
Such was the case on Wednesday, July 17 when seemingly out of nowhere, a shiny Tramea lacerata "black saddlebags" appeared in front of me on the sidewalk fronting the Vacaville Chamber of Commerce.
Its habitat is near ponds, lakes, ditches, slow streams, or other bodies of water, but there it was.
"It is a freshly emerged female, probably on its maiden flight," said naturalist Greg Kareofelas of Davis, an associate with the Bohart Museum of Entomology, University of California, Davis. "This is its most vulnerable time. If it gets through the next day or so, off to fast flying it will go and you will never get close to it again."
I gingerly picked it up and photographed it on a Mexican sunflower (Tithonia). Half an hour later, I witnessed it fly over our fish pond, never to be seen again. At least by me!
This species, found throughout North America, is included in a Bohart Museum's poster, "Dragonflies of California." Designed by Fran Keller (then a doctoral student in entomology at UC Davis and now an assistant professor at Folsom Lake College), with images by Kareofelas, the poster is available in the Bohart Museum's gift shop in Room 1124 of the Academic Surge Building on Crocker Lane, UC Davis campus.
The black saddlebags dragonfly belongs to the Order Odonata (dragonflies and damselflies), suborder Anisoptera (dragonflies) family Libellulidae (skimmers), genus Tramea (saddlebags) and species lacerata (black saddlebags). "It flies constantly, often gliding, perches infrequently," according to BugGuide.net. The University of Michigan biokids website yields more information.
It's easily distinguishable. Says Wikipedia: "It has distinctive wings with characteristic black blotches" at its proximal ends, "which make the dragonfly look as though it is wearing saddlebags. The black saddlebags is a relatively large dragonfly at about 5 centimeters in length. The body is thin and black, and the female may have lighter spotting or mottling dorsally. The head is much wider than the rest of the body and is dark brown in color...Some populations of this dragonfly undertake migrations. Both the larvae and adult forms are efficient predators of mosquitoes so they are a helpful insect to have in wet areas where mosquito infestations occur." A wonderful predator...
Of predators, sidewalks and black saddlebags...
What a show!
Last weekend we spotted female European wool carder bees (so named because they collect or card plant hairs for their nests) buzzing in and out of our snapdragons.
The bees, about the size of honey bees, are mostly black and yellow. The females range in body length from 11 to 13 millimeters, while the males are 14 to 17 mm.
The males are very territorial. As we mentioned in a previous Bug Squad blog, they put the "terror" in territorial. The males bodyslam other insects, as they try to protect their turf, per chance to mate with the females. We've seen the males terrorize the much larger Valley carpenter bees--bodyslamming them, dislodging them and chasing them away.
The European wool carder bees, Anthidium manicatum, are natives of Europe. Their "immigrant ancestor" was first detected in the United States (New York) in 1963, and the species spread west. It was first recorded in California (Sunnyvale) in 2007.
The bee, according to research entomologist Tom Zavortink of the Bohart Museum of Entomology at UC Davis, was accidentally introduced into New York state. It was not purposefully introduced to pollinate alfalfa, as some reports allege, he said.
Writing in a 2008 edition of the Pan-Pacific Entomologist, Zavortink and fellow entomologist Sandra Shanks, now of Port Townsend, Wash., pointed out that several papers “have documented its spread from neighboring areas in the northeastern United States and southern Canada” and that the species has since crossed the country. It was confirmed in Colorado in 2005, Missouri in 2006, and Maine, Michigan, Maryland and California (Sunnyvale) in 2007, the entomologists wrote. Records show it was first collected in Davis on July 26, 2007.
It was well established in the Central Valley by 2008, according to Lynn Kimsey, director of the Bohart Museum of Entomology and UC Davis professor of entomology.
In Vacaville, we first encountered the European wool carder bee in the spring of 2010.
Its plant preferences include lamb's ear (Stachys byzantine, in the mint family Lamiaceae), a perennial grown for its fuzzy, silvery gray-green foliage. It's also been collected in the figwort/snapdragon family (Scrophulariacae) and the pea and bean family (Fabaceae), according to the Zavortink-Shanks research.
Usually the European wool carder bees are hanging around our foxgloves and catmint (neither is blooming yet) and our lavender (blooming but being ignored).
But snapdragons? We've never seen them foraging on snapdragons (Antirrhinum) until now. That's because we've never planted snapdragons until this spring!
It's about 150 years old, 50 feet in height, and measures about five feet in diameter. And it's dying.
What's killing it is thousand cankers disease (TCD), an emerging insect-fungus complex.
It's killing a lot of black walnut trees.
In fact, TCD has caused profound damage to black walnut trees not only in urban areas of California and other western states, but in Pennsylvania, Tennessee and Virginia, according to a newly published review by UC Davis-affiliated scientists and their colleagues.
The article, “Status and Impact of Walnut Twig Beetle in Urban Forest, Orchard and Native Forest Ecosystems,” published in the Journal of Forestry, updates the spread of the disease, and chronicles the role of the bark beetle, Pityophthorus juglandis, and the canker-producing fungus, Geosmithia morbida, in killing walnut trees, especially black walnuts.
Native to southwestern United States and northern Mexico, the bark beetle, about half the size of a grain of rice, “has invaded urban, orchard and native forest habitats throughout the United States, as well as Italy,” said lead author and forest entomologist Steven Seybold of the Pacific Southwest Research Station, USDA Forest Service, Davis, and a lecturer and researcher with the UC Davis Department of Entomology and Nematology.
Walnut twig beetles (WTB) tunnel into branches and trunks of walnut (Juglans) where they create galleries for mating and reproduction. They carry spores of the fungus into their galleries, and the resulting fungal infection causes formation of cankers, which coalesce and girdle branches and stems.
“The walnut twig beetle is a significant pest of very large trees because it sequentially attacks the small branches--though ironically not the twigs--all the way down the trunk to the soil line,” said Seybold, a pioneering scientist of TCD, who first found TCD evidence in Davis in 2008. “Most bark beetle species are not this thorough in using all of the phloem tissue in their plant hosts. In Davis right now, in the courtyard next to Sophia's Thai Restaurant, 129 E St, the tiny beetle is gradually killing the largest northern California black walnut tree in the city. It has taken nearly a decade, but the crown of the massive tree is nearly completed killed.”
Seybold estimated that the E Street tree is about 150 years old, "maybe older." It measures almost 65 inches or just over five feet.
Seybold noted that the disease is “unique because of its multifaceted negative impact on walnut trees involved in landscaping, food production, and forestry. Walnut trees are valuable ecologically and for food and timber, so the walnut twig beetle is a good model in which to study the impact of a bark beetle on forest and agro-ecosystem services.”
The five co-authors of the synthesis article include Stacy Hishinuma and Andrew Graves, two USDA forest entomologists with UC Davis connections. Hishinuma, who works in the Pacific Southwest Region, San Bernardino, and holds a doctorate in entomology from UC Davis, studied in the Seybold and Mary Lou Flint labs, UC Davis Department of Entomology and Nematology. Graves, who works in the Southwestern Region, Albuquerque, N.M., is a former postdoctoral fellow in the UC Davis Department of Plant Pathology.
Other co-authors are Professor William Klingeman III of the Department of Plant Sciences, University of Tennessee, and forest entomologist Tom Coleman with the USDA Forest Service's Southern Region, Asheville, N.C..
UC Davis doctoral student Jackson Audley of the Seybold lab and Richard Bostock lab (Plant Pathology), contributed photos of dead and dying walnut trees in the Davis area, along with UC Davis doctoral student Corwin Parker and Hishinuma. Audley, who is researching an ensemble of behavioral chemicals that repel the walnut twig beetle from landing on English walnut trees, conducts his research in a commercial orchard near Winters.
“WTB is one of a few invasive bark beetles in North America where expanding distribution and impact have been pronounced enough to affect other species, communities, and ecosystems to the extent that services provided by urban forests, agroecosystems, and wildland areas have been altered,” the co-authors concluded in their paper. “We envision that ecological impacts of WTB will continue to unfold across a wider geographic area to affect various types of key services, i.e., provisioning (e.g., timber and nontimber products); regulating (e.g., air and water quality/quantity, climate regulation); and cultural (e.g., recreation, aesthetics, shade) services.”
Scientists first collected the beetle in North America in 1896 in New Mexico, 1907 in Arizona, 1959 in California, and 1960 in Mexico, but never considered it a major pest of walnut trees until black walnuts began deteriorating and dying in New Mexico in the early 2000s. Walnut tree mortality that occurred in the early 1990s in the Wasatch Mountains of Utah and in the Willamette Valley of Oregon is now attributed to TCD.
“Currently, good cultural practices and sanitation of infested materials are the primary strategies for disease management within orchards and also for prevention of spread of the disease and vector to regions with low rates of infection,” according to the UC Statewide Integrated Pest Management Program (UC IPM)>
UC IPM recommends that trees with less than 50 percent live crown be removed to reduce the buildup of walnut twig beetles and inoculum in the trunk and larger scaffold branches. "Chemical control with either fungicides or insecticides is not recommended for management of thousand cankers disease," UC IPM says.
Which brings us back to the massive black walnut tree that is dying on E Street in Davis. If it dates back to 1868, that's the year the city of Davis was founded. Its namesake, Jerome C. Davis, owned a stock farm on the site.
Who was in the White House and who was in the California governor's mansion that year? Andrew Johnson and Henry Haight, respectively. That was also the year that trustees founded the University of California in Oakland; Clark Kerr became the first president. And 1868 was the year Memorial Day was first observed in the United States...and when author Louisa May Alcott published the first volume of her coming-of-age novel, Little Women.
The little tree in Davis became of age, too, growing into a giant tree offering shade, shelter and sustenance. Who would have thought that a tiny insect, half the size of a grain of rice, would play a major role in its demise?
We celebrate honey bees every day, but they are especially celebrated on May 20, World Bee Day. It's an annual day to raise awareness about the importance of bees and beekeeping. It's a day to acknowledge the industriousness of Apis mellifera, their role in our lives, and their place in our ecosystem. Bees pollinate a third of the food we eat.
A bit of history: The United Nations approved Slovenia's proposal to proclaim May 20 as World Bee Day in December of 2017. Slovenia also sought to pay tribute to noted beekeeper and native son Anton Janša (1734-1773) of Carniola (now Slovenia), a pioneer of modern apiculture, a noted painter, and an apiculture teacher at the Habsburg Court in Vienna.
Janša became a full-time beekeeper in 1769. He began by tending his father's 100 hives, but a year later, he received a royal appointment as Austria's teacher of apiculture. He kept bees in the imperial gardens (Augarten) and traveled the country, eager to present information about his beloved bees.
Janša "became famous for his lectures in which he demonstrated his knowledge of bees," according to Wikipedia. "He also wrote two books in German: Discussion on Beekeeping and A Full Guide to Beekeeping. The latter was published in 1775, after his death. In Full Guide, Janša noted: Bees are a type of fly, hardworking, created by God to provide man with all needed honey and wax. Amongst all God's beings there are none so hard working and useful to man with so little attention needed for its keep as the bee."
A tip of the veil to Anton Janša!
More locally, the Häagen-Dazs Honey Bee Haven, part of the UC Davis Department of Entomology and Nematology, celebrated bees during the "Take Our Daughters and Sons to Work" Day. UC Davis employees and their offspring visited the half-acre garden on Bee Biology Road, admiring the flowers and the six-foot-long bee sculpture, Miss Bee Haven, that anchors the garden. The ceramic-mosaic sculpture is the work of Donna Billick of Davis, a self-described "rock artist."
Anton Janša would have felt right at home!
Among the bee haven visitors that day were two beekeepers: elementary school student Adelaide Grandia of Woodland and her grandfather Dwight Grandia of Gulf Shores, Alabama, who has kept bees for 39 years. "I've had hives in the Atlanta area for 25 years and in northern Alabama for 10 years," he said. "I'm teaching my granddaughter beekeeping." He recently set up a bee hive for her.
"My grandpa is a beekeeper," Adelaide said, "and a pilot." Her mother, UC Davis Professor Liza Grandia of Native American Studies, is also interested in bees.
David Hernandez, who works in the Facilities Management Steam Shop, brought his sons, Aayden, 10, and Evan, 8. They checked out the garden, installed in the fall of 2009, and gathered for a photo behind the pollinator cut-out board, as did colleague Kris McBride of the Facilities Management Steam Shop and son, Deegan, 4-1/2.
UC Davis staff employee Xu Chunying and son, Andy, delighted in the catch-and-release activity, in which youths catch bees in a vacuumlike tube device, examine them, and then release them. Honey bees, native bees and carpenter bees are favorite subjects.
Ariel Cormier, who works in the Office of the Chancellor and Provost as manager of Budget and Financial Analysis, attended with her eight-year-old twin daughters Casey and Gabrielle. They delighted in the bees, blossoms, and the beautiful day.
The Häagen-Dazs Honey Bee Haven, located next to the Harry H. Laidlaw Jr. Honey Bee Research Facility, is open to the public from dawn to dusk. Admission is free. Group tours are also available for a small charge. For more information, access the website.
When you're a little kid and there's a huge bee towering over you, what do you do?
You do what comes naturally.
Kids reacted differently toward the adults who donned the California Master Beekeeper Program's queen bee costume at the third annual California Honey Bee Festival last Saturday in downtown Woodland.
Some looked at Ms. Queen Bee, quite quizzically. What's that?
Others gave her the high five, a smile, a giggle, or a hug as their parents moved in closer to take photos.
But one little boy clutching a stuffed toy pink pig did three things. First he offered an outstretched hand for a high five. Then he introduced his pink pig to Ms. Queen Bee. After the proper introductions, he asked if she would remove her head so he could see her face.
Ms. Queen Bee obliged, much to his delight.
The sign in front of the California Master Beekeeper Program (CAMPB), which is directed by Extension apiculturist Elina Lastro Niño of the UC Davis Department of Entomology and Nematology, succinctly explained what the program is all about: "Educating stewards and ambassadors for honey bees and beekeeping."
Master Beekeeper Wendy Mather, program manager of CAMPB, and several others staffed the booth, while research associate Bernardo of the Niño lab opened hives inside a screened tent to show visitors what a colony looks like. Bernardo, who serves as the educational supervisor for CAMPB, introduced the crowd to the queen bee, worker bees and drones.
The California Honey Festival, sponsored by the City of Woodland and the UC Davis Honey and Pollination Center, included a cooking stage, a UC Davis educational stage, a kids' zone, a refreshment zone, and live entertainment.
UC Davis was well represented. Among the UC Davis attractions: the Honey and Pollinator Center offered free honey tasting; the Bohart Museum of Entomology displayed both live insects and specimens; the UC Davis Häagen-Dazs Honey Bee Haven provided pollinator gardening information; the UC Davis Graduate Student Association offered t-shirts; and the UC Davis Stores offered a selection of beekeeping and bee books, including "The Honey Bee Hobbyist: The Care and Keeping of Bees" by emeritus professor and retired bee wrangler Norm Gary.
More than 30,000 people attend the festival every year. Its mission: to promote honey, honey bees and their products, and beekeeping. Through lectures and demonstrations, the crowd can learn about bees and how to keep them healthy. Issues facing the bees include pests, pesticides, diseases, malnutrition, and climate changes.
And sometimes understanding honey bees all begins when a little kid can engage with a smiling, costumed queen bee--and she obligingly removes her head!