Backyard Orchard News
Every insect looks prettier when it lands on a tower of jewels (Echiium wildpretti).
When in full bloom, the 9-to-10-foot-high plant, native to the Canary Islands, blazes with firecracker-red flowers. It's a showstopper.
Syrphid flies, aka flower flies or hover flies, battle with honey bees to sip the sweet nectar.
The flower flies flit in and out of the blossoms, barely visible.
However, these insects suffer from an identity crisis. Their wasp-like coloring wards off predators. That same coloring confuses people, too. The average person on the street--or in a flower bed--thinks they're bees.
They're not. They're flies.
UC Davis-trained entomologist Robert Bugg wrote an excellent pamphlet on flower flies that's downloadable free from the UC Division of Agriculture and Natural Resources. Titled Flower Flies (Syrphidae) and Other Biological Control Agents (Publication 8285, May 2008), it will help you identity flower flies.
Not bees. Not wasps. Flies.
When we think of pollinators, we usually think of honey bees, bumble bees, carpenter bees, syrphid or flower flies, and butterflies.But wait, blow flies can be pollinators, too.
You see them stopping on flowers for a sip of nectar, and in their travels from one flower to the other, they can--and do--transfer pollen.
Blow flies, though, aren't exactly what the organizers of National Pollinator Week had in mind when they set aside June 21-27 to celebrate the pollinators.
The U. S. Forest Service says that "of the 1,400 crop plants grown around the world, i.e., those that produce all of our food and plant-based industrial products, almost 80% require pollination by animals. Visits from bees and other pollinators also result in larger, more flavorful fruits and higher crop yields. In the United States alone, pollination of agricultural crops is valued at $10 billion annually. Globally, pollination services are likely worth more than $3 trillion."
So, when we talk about "the birds and the bees and the flowers and the trees," we ought to include an occasional blow fly from the order Diptera and family Calliphoridae.
Besides, this little bugger does lend itself to alliteration: birds, bees, bats, beetles, butterflies and blow flies.
Blow Fly on Lavender
Like a crab, the crab spider can move sideways and backwards as it stalks and ambushes its prey. It grabs the unsuspecting insect with its powerful front legs, bites it, and paralyzes it.
Dinner is served.
However, this particular spider seemed to be perusing a menu. Hmm, a blow fly, a hover fly, a sweat bee or a honey bee? It watched honey bees glide onto the sedum and sip nectar. It was touch-and-go; the spider would crawl to a bee, touch it, and the bee would buzz off.
"It must not have been hungry--otherwise the bee would have been toast," Kimsey said.
We watched the spider for half an hour. The predator and the prey.
This time the prey won. Every single bee escaped. No toast today.
Spider and the Bee
Over and Out
The killer: thousand cankers disease. The victim: native black walnuts. The speaker: Steve Seybold.
Seybold (right), a research entomologist with the Chemical Ecology of Forest Insects, USDA Forest Service, Pacific Southwest Research Station, Davis, will speak on “Walnut Twig Beetle and Thousand Cankers Disease: Characterizing an Emergent Threat to Forest and Agroecosystems in North America” at a noonhour seminar sponsored by the UC Davis Department of Entomology. It will take place from 12:10 to 1 p.m., Wednesday, May 19 in 122 Briggs Hall on Kleiber Drive.
Thousand cankers disease is a newly discovered disease that is becoming a “significant problem” in California and seven other western states and could very well spread throughout the United States, researchers say.
“Thousand cankers disease, caused by a newly described fungus spread by the tiny walnut beetle, has been detected in 15 California counties from Sutter County to Los Angeles,” said Seybold, a chemical ecologist and affiliate of the UC Davis Department of Entomology.
How can a tiny little beetle fell a mighty tree? When it's associated with a specific fungus, a newly described fungus that's so new it has no name.When it tunnels into the wood, the walnut twig beetle (Pityophthorus juglandis) carries the fungus (proposed name of Geosmithia morbida) with it. Often the first symptoms of the disease are flagging and yellowing leaves and branch dieback. Affected branches show sap staining and pinhole-sized beetle holes. Peel back the bark and you'll see dark stains caused by the fungus.
To date, the disease has been found in Utah, Colorado, New Mexico, Arizona, Idaho, Washington as well as California.
“The potential spread of the disease to the eastern United States is now of great concern, especially through movement of infested/infected raw wood and firewood,” Seybold said.
The walnut twig beetle, believed to be native to Arizona, California, New Mexico, and Mexico, was first collected in Los Angeles County more than 50 years ago.
The disease was first noticed in canker-riddled black walnuts in Utah and Oregon in the early 1990s, but scientists attributed that to environmental stress. In 2006, plant pathologist Ned Tisserat and entomologist Whitney Cranshaw of Colorado State University identified the pathogen and characterized its association with the beetle in declining black walnut trees in central Colorado.
This is a very serious disease of black walnuts. Let's hope they don't go the way of the American chestnut or the American elm.
Walnut Twig Beetle
If you have a bee hive, you most likely have mites.
Varroa mites, those blood-sucking parasites that latch onto the brood and also thrive on the adult bees, can weaken and destroy a hive.
Extension apiculturist Eric Mussen, member of the UC Davis Department of Entomology faculty, frequently fields calls about varroa mites.
In his latest edition of from the UC apiaries, he points out that "obtaining fumigants for varroa mite control may be somewhat difficult at this time for beekeepers."
"I haven't checked on the Apiguard® situation recently, but shipments from Europe had been held up, apparently by U.S. customs," Mussen wrote. "The other desired fumigant, Mite Away II pads, are vanishing from the market quickly. They are out of production and soon will not be available. The reason behind this is because NOD Apiary Products, in Canada, has decided to stop producing the pads and instead offer a formic acid product in strip form."
Today we spotted a varroa mite on a foraging bee. The bee, a golden Italian, was nectaring lavender.
Unfortunately, a nasty little parasite was eating at her.