We all take short cuts--short cuts around the campus, to the beach, to a favorite restaurant...
Honey bees take short cuts, too.
We've often watched assorted bumble bees and carpenter bees drill a hole in a long-tubed flower to rob the nectar.
And we've watched honey bees benefitting from this behavior.
Today we observed a carpenter bee, Xylocopa tabaniformis orpifex, engaging in nectar robbing in salvia at the UC Davis Arboretum. Nectar robbing occurs when a bee or other animal circumvents the usual plant-pollinator relationship and "cheats" by entering a flower from the outside to steal nectar, thus avoiding pollination or contact with the anthers.
There's excellent information on bumble bees, their habitat needs, their behavior, and identifying characteristics in a free, downloadable PDF from the Xerces Society for Invertebrate Conservation: "Conserving Bumble Bees: Guidelines for Creating and Managing Habitat for America's Declining Pollinators."
The PDF mentions that "short-tongued bumble bees will engage in 'nectar robbing' from flowers with a long corolla tube by biting holes at the base of the corolla and drinking the nectar from the outside of the flower." The bee grabs the reward but doesn't contribute to "the plant's pollination needs."
Meet a carpenter bee.
This one (below) is a male carpenter bee, Xylocopa tabaniformis orpifex, as identified by native pollinator specialist Robbin Thorp, emeritus professor of entomology at the University of California, Davis.
It's also called a "mountain" or "foothill" carpenter bee.
When it slits the corolla of the flower--in this case, salvia--and bypasses the pollination process--this is called "nectar robbing."
The mountain/foothill carpenter bee is the smallest of the three species of carpenter bees in California, Thorp says. The other two are the Valley carpenter bee, Xylocopa varipuncta, the largest, and the California carpenter bee, Xylocopa californica, the second largest.
The male of the Valley carpenter bee is a green-eyed blond and often referred to as a "teddy bear." The female of that species is solid black. And huge!
The California carpenter bee or Xylocopa californica is known for its distinctive distinctive bluish metallic reflections on the body, Thorp says. The females have dark smokey brown wings.
The one photographed below, Xylocopa tabaniformis orpifex, is common in the center of the Central Valley, "probably due primarily to increased nest sites such as redwood arbors and fences," Thorp says. Although considered a pollinator instead of a pest, "it can be a pest when it gets into untreated redwood used for water tanks or structural timbers," Thorp points out. "The females are black with light smokey-colored wings. The male has bright yellow marks on the lower part of its face and some yellow hairs on the top front of its thorax."
You can see the yellow hair on the thorax.
And how big is the smallest of the three carpenter bees? "Much larger than a honey bee, but about half the size of the other two carpenter bees," Thorp says.
So you're sitting in your yard having your morning coffee, and you get buzzed--not a buzz from the caffeine but a buzz by a carpenter bee.
A male carpenter bee, Xylocopa tabaniformis orpifex, is guarding the salvia, fending off all other male suitors as it waits for a female to arrive. Then, seeking a quick energy fix, our subject stops to rob the nectar (when carpenter bees slit the corolla, bypassing the pollination process, it's called "robbing the nectar").
We managed to photograph this male carpenter (below) in quick succession: (1) in flight (2) stealing the nectar and (3) jumping off the flower.
Xylocopa tabaniformis orpifex is the smallest of the three carpenter bee species found in California, according to native pollinator specialist Robbin Thorp, emertius professor of entomology at UC Davis. The other two species: X. varipuncta and X. californica. (See UC Davis Department of Entomology website.)
X. tatabaniformis orpifex may be the smallest, but you wouldn't know it by its buzz.
The carpenter bees (Xylocopa tabaniformis orpifex) of the Central Valley have emerged and are creating their own little Lovers' Lane on the salvia.
More males than females. More buzzing than foraging. More chasing than capturing.
This is the "bug" that some folks are afraid of--they describe them as "big black bees heading right at me and scarin' the livin' daylights of me--close enough for a buzz cut."
Well, the males ARE quite territorial. But only the females are solid black. The males have yellow on their thorax and head.
But hey, they shouldn't scare the livin' daylights out of you. They're pollinators.
It's good to know your floral visitors. Not all floral visitors are honey bees. Some are carpenter bees, bumble bees, wool carder bees, longhorned bees, and leafcutting bees, to name a few. Some are syrphid flies that mimic bees and wasps.
If you're yearning to learn more about pollinators, then the all-day Pollinator Gardening workshop on Saturday, April 28 in Room 1001 of Giedt Hall, UC Davis, is for you. "Your Sustainable Backyard: Pollinator Gardening" is sponsored by the California Center for Urban Horticulture (CCUH) at UC Davis. Among the speakers: native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, who will discuss "Bees 101: Species Diversity and Behavior." Yes, that will include carpenter bees.
Thorp's knowledge of all things bees is totally amazing. You'll come away wanting to spread the word: carpenter bees are pollinators, too. Don't fear them.
Pollination ecologist Neal Williams, assistant professor of entomology at UC Davis, will share the "Importance of Pollinators and Conservation." Ellen Zagory, director of horticulture at the UC Davis Arboretum, will cover "Bee Plants." Vicki Wojcik, associate program manager of Pollinator Partnership, will speak on "Pollinator Gardening: Design and Maintenance."
You'll "learn about bees and what they do, and how gardeners can support healthy populations through simple gardening practices," said coordinator Melissa "Missy" Gable, horticulturist and program director of CCUH. "This workshop is intended for anyone with a love of gardening."
"We have entomologists, horticulturists and design experts presenting at Pollinator Gardening," Gable said. "This workshop is designed both to inspire gardeners and equip them with all the necessary tools to provision pollinating insects in their own landscape. Without the pollination services of European honey bees and native bees, what fruits and vegetables would be accessible to us? Come learn what you can do your part to support healthy bee communities." Check out the registration site.
Following the workshop, participants can visit (1) the Häagen-Dazs Honey Bee Haven, a half-acre bee friendly garden next to the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road and (2) the UC Davis Arboretum Teaching Nursery on Garrod Drive and perhaps buy a plant or two. The haven is open all year around from dawn to dusk (free admission) while the teaching nursery will be open that afternoon to registered participants for a look-see at the demonstration gardens and for plant sales.
Perhaps, just perhaps, you might want to buy salvia to attract such floral visitors as carpenter bees!
Carpenter bees pack pollen, too.
A carpenter bee (Xylocopa tabaniformis orpifex) visiting our gaura last weekend was packing bright yellow pollen, a sharp contrast against her black body.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at the University of California, Davis, said that "the large triangular pollen grains of this and other Onagraceae are held together in strings by viscin threads. You can see this on the anther above the bee’s head. This makes it a challenge for some bees to neatly pack this pollen, but helps pollen to get draped on the plant stigma."
The UC Davis Department of Entomology website includes information on three species of carpenter bees commonly found in California.