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Cooperative Extension San Joaquin County

Posts Tagged: Robbin Thorp

About Those Sleepovers...

We're receiving lots of inquiries about sleepovers ever since we began posting images of male longhorned bees, Melissodes agilis, sleeping on our lavender.

Boys' Night Out!

While the females sleep in their underground nests, the males cluster on stems. No, they don't have pillow fights or nightcaps but they do wiggle around a lot until they get comfortable.

Now the boys have moved from their favorite spot on the lavender (vertical sleepover) to the guara (horizontal sleepover). We suspect this may be due to several reasons: (1) The presence of three praying mantids in the lavender (2)  the lavender is fading while the guara is flourishing and (3) the guara offers a definite height advantage, which may deter a few predators (but not birds).

Nevertheless, the boys start arriving for their nightly sleepover around 5 p.m. and don't budge until around 7 p.m., sometimes as late as 9 or 10.

One reader asked some interesting questions.

"There is a nightly cluster of boys on an aster stem in my front yard and I wanted to find out more about them. In particular, do they/can they/will they sting?"

No, boys don't sting--just the girls. As native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, explains: "Boy bees cannot sting.  They lack a stinger which is a modified ovipositor in their wasp ancestors.  Occasionally a girl bee may spend the night out if she is caught by sudden drop in temperature.  Usually she will not be part of a group sleep over.  So don't attempt to handle unless you are confident you can tell boy bees from girl bees or they are too sleepy to defend themselves."

The reader also asked: "Typically how close to the girls' nest(s) do the boys' slumber? I want to try and make sure I don't touch it when planting at end of summer."

Says Thorp: "Boy sleeping aggregations are based on a suitable perch and not related to where females are nesting, but probably no more than 100 yards from the nearest female nest.  Females nest in the ground and have rather distinctive round holes about the diameter of a pencil or slightly smaller, sometimes with small piles of dirt around them looking like mini-volcanos.  The holes may be widely separated or clustered together depending on the species, but each female digs her own burrow."

Of course, not all slumbering bees in this area are Melissodes agilis,  as Thorp points out. Some may be other species of the genus Melissodes and some may belong to the closely related Svastra obliqua.

The reader also wondered: "When watching the boys tonight, about ten of them started waking up and kicking each other. They finally settled down and started to nestle back in for the 'night'--it was only 6 p.m.--but I wasn't sure if my presence was getting them riled or they tend to act like kids sharing a bed?"

Says Thorp: "The boys usually settle in as the light dims in the evening.  Cool, and drizzly conditions may modify bed time.  Each establishes his own spot, so there may be some jostling for position initially."

We've noticed that, too. We've also noticed that the early morning risers--the carpenter bees, bumble bees, honey bees and syrphid flies--work around the slumbering Melissodes agilis. All that buzzing must sound like the human version of a chainsaw. "Will ya shaddup, already? Can't you see we're trying to sleep?"

Once the boys awaken, though, watch out! They'll dive-bomb the pollinators or any critter working or resting on "their" flowers.  They're very territorial and determined to save the food source for the females of their species. The butterflies, including the Western tiger swallowtail, anise swallowtail, Gulf Fritillary and cabbage whites, don't linger when the boys target them.

And speaking of California bees, we're eagerly awaiting the arrival of the book, California Blooms and Bees: an Identification Guide for Gardeners and Naturalists. It's co-authored by research entomologist/professor Gordon Frankie of UC Berkeley; Thorp (who received his doctorate from UC Berkeley); and their UC Berkeley affiliates, photographer/entomologist Rollin Coville and floral/herbarium curator Barbara Ertter.

More than 1600 species of undomesticated bees call California their home. The authors focus on 22 of the most common genera and the flowers they frequent.

Meanwhile, you'll want to check out Frankie's UC Berkeley Urban Bee Lab website to read more about native bees and his exciting research.

Male longhorned bees jockeying for position on a guara stem. (Photo by Kathy Keatley Garvey)
Male longhorned bees jockeying for position on a guara stem. (Photo by Kathy Keatley Garvey)

Male longhorned bees jockeying for position on a guara stem. (Photo by Kathy Keatley Garvey)

Not every stem is taken and not all the males cluster six or seven to a stem. These two appear to want space. (Photo by Kathy Keatley Garvey)
Not every stem is taken and not all the males cluster six or seven to a stem. These two appear to want space. (Photo by Kathy Keatley Garvey)

Not every stem is taken and not all the males cluster six or seven to a stem. These two appear to want space. (Photo by Kathy Keatley Garvey)

This male Melissodes agilis, is sleeping solo on a guara blossom. (Photo by Kathy Keatley Garvey)
This male Melissodes agilis, is sleeping solo on a guara blossom. (Photo by Kathy Keatley Garvey)

This male Melissodes agilis, is sleeping solo on a guara blossom. (Photo by Kathy Keatley Garvey)

Posted on Monday, July 28, 2014 at 10:01 PM

Bumble Bees and Spiders Don't Mix?

Bumble bees and spiders don't mix, you say?

Well, they will at the Bohart Museum of Entomology's open house from 1 to 4 p.m., Saturday, July 26. The family-centered event, free and open to the public, takes place in Room 1124 of the Academic Surge building on Crocker Lane, UC Davis campus.

Actually the theme is about spiders: "Arachnids: Awesome or Awful?" There you'll see black widow spiders, jumping spiders, cellar spiders and the like. But you don't have to "like" them as you do posts on Facebook!

You can also learn about bumble bees. Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, will be one of the tour guides.  Thorp co-authored the newly published Bumble Bees of North America: An Identification Guide, which is available in the Bohart gift shop. He can autograph your book and answer questions about how to attract bees to your garden.

Thorp was recently interviewed by Tom Oder of the Mother Nature Network on how to garden for bumble bees. So was Steve Buchmann, an adjunct professor in entomology and ecology at the University of Arizona.

Thorp told Mother Nature Network that some bumble bees are in very serious decline, and others are doing quite well.

So, how do you attract them to your garden? Buchmann was quoted as saying: “Gardening for bumblebees is similar to gardening for other bees and pollinators."  To entice bumblebees to visit your garden, “plant mints, Salvia, Monarda, plants in the sunflower family and clovers."

Read Oder's article for more information.

And keep your eyes open for the soon-to-be-published California Bees and Blooms: A Guide for Gardeners and Naturalists, co-authored by entomologist Gordon Frankie of UC Berkeley, Thorp, and two others with UC Berkeley connections: photographer/entomologist Rollin Coville and floral curator Barbara Ertter.

As for Saturday, July 26 there won't be a vote on whether you like bumble bees or spiders better, nor will you be asked to sing "Itsy Bitsy Spider" or "Baby Bumble Bee." It promises, though, to be fun and educational. Plus, you can enjoy the live  "petting zoo," featuring 24-year-old Rosie the tarantula, assorted walking sticks, and the colorful Madagascar hissing cockroaches. Yes, they hiss.

The gift shop is also popular. You can browse through the books, jewelry, t-shirts, sweatshirts, insect-themed candy, butterfly houses, and insect-collecting kits.

The Bohart Museum, directed by Lynn Kimsey, professor of entomology at UC Davis, houses nearly eight million insect specimens and is the seventh largest insect collection in North America. It is also the home of the California Insect Survey, a storehouse of insect biodiversity. Noted entomologist Richard M. Bohart (1913-2007) founded the museum.

 

The museum's regular hours are from 9 a.m. to noon and 1 to 5 p.m. Mondays through Thursdays. It's closed to the public on Fridays and on major holidays. Admission is free. For more information, email education and outreach coordinator Tabatha Yang at tabyang@ucdavis.edu or telephone her at (530) 752-0493.

A camouflaged jumping spider eyes a honey bee on Japanese anemone. (Photo by Kathy Keatley Garvey)
A camouflaged jumping spider eyes a honey bee on Japanese anemone. (Photo by Kathy Keatley Garvey)

A camouflaged jumping spider eyes a honey bee on Japanese anemone. (Photo by Kathy Keatley Garvey)

Robbin Thorp points at a yellow-faced bumble bee, Bombus vosnesenski. (Photo by Kathy Keatley Garvey)
Robbin Thorp points at a yellow-faced bumble bee, Bombus vosnesenski. (Photo by Kathy Keatley Garvey)

Robbin Thorp points at a yellow-faced bumble bee, Bombus vosnesenski. (Photo by Kathy Keatley Garvey)

Posted on Friday, July 25, 2014 at 9:12 PM

Karate Kick!

If you've ever watched a karate competition, you've probably seen the roundhouse kick, tornado kick, the reverse roundhouse kick or the flying side kick.

But have you ever seen a bee do that?

We were photographing sunflower bees on our Mexican sunflowers (Tithonia) yesterday, trying to catch the territorial dive-bombing. We were shooting with a Canon E0S 7D equipped with a 100mm macro lens. Settings: ISO, 1600. Shutter speed,  1/1400 of a second. F-stop, 10.

If bees could engage in humanlike conversation, imagine this dialogue:

"This flower is mine! Get off! I want my ladies to have that flower!"

"No, it's not! It's mine. I was here first! Leave me alone!"

For awhile, a large bee, a male longhorned bee, Svastra obliqua (as identified by native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis), appeared to be the "king of the mountain." It held its ground...er...floral resource.

Suddenly, faster than my shutter speed, a smaller bee of a different species, a male longhorned bee, Melissodes (probably Melissodes agilis, Thorp said) headbutted Svastra,  a scene reminiscent of a World Cup play.

One swift kick by Mr. Svastra and a surprised Mr. Melissodes shot straight up in the air, whirling end over end. 

Roundhouse kick? Tornado kick? Reverse roundhouse kicK? Flying side kick?

Whatever it was, the "bee master" won.

And he wasn't even wearing a black belt.

A male longhorned sunflower bee, Svastra obliqua, foraging on a Mexican sunflower. (Photo by Kathy Keatley Garvey)
A male longhorned sunflower bee, Svastra obliqua, foraging on a Mexican sunflower. (Photo by Kathy Keatley Garvey)

A male longhorned sunflower bee, Svastra obliqua, foraging on a Mexican sunflower. (Photo by Kathy Keatley Garvey)

A male longhorned sunflower bee, Melissodes agilis (right), targets the larger Svastra obliqua. (Photo by Kathy Keatley Garvey)
A male longhorned sunflower bee, Melissodes agilis (right), targets the larger Svastra obliqua. (Photo by Kathy Keatley Garvey)

A male longhorned sunflower bee, Melissodes agilis (right), targets the larger Svastra obliqua. (Photo by Kathy Keatley Garvey)

Melissodes agilis shoots straight up after a powerful kick by Svastra obliqua. (PHoto by Kathy Keatley Garvey)
Melissodes agilis shoots straight up after a powerful kick by Svastra obliqua. (PHoto by Kathy Keatley Garvey)

Melissodes agilis shoots straight up after a powerful kick by Svastra obliqua. (PHoto by Kathy Keatley Garvey)

Melissodes agilis (left) goes sprawling. (Photo by Kathy Keatley Garvey)
Melissodes agilis (left) goes sprawling. (Photo by Kathy Keatley Garvey)

Melissodes agilis (left) goes sprawling. (Photo by Kathy Keatley Garvey)

Posted on Monday, July 7, 2014 at 8:50 PM

A Pollinator with a New Name

We're almost midway through National Pollinator Week

It's a week that we should celebrate every day.

Last weekend we spotted a newcomer to our backyard bee garden: a bumble bee species, Bombus fervidus, formerly known as Bombus californicus, as identified by native pollinator specialist Robbin Thorp, emeritus professor of entomology at the University of California, Davis, and bumble bee enthusiast Gary Zamzow of Davis.

The female was heading toward a purple coneflower, Echinacea purpurea, and then touched down in a "Queen-of-the-Mountain" moment.

This bumble bee species is commonly known as "the yellow bumble bee," according to the co-authors of the newly published Bumble Bees of North America: an Identification Guide, authored by Paul Williams, Robbin Thorp, Leif Richardson and Sheila Colla (Princeton University Press).

It's widely spread across the continent. "Evidence from DNA barcodes supports a close relationship between individuals with the darker color pattern in the west (named californicus) and individuals with the lighter color patterns in the east (named fervidus)," they wrote.

So, despite the images of californicus all over the web, including BugGuide.net and discoverlife.org, it and fervidus appear to be the same species.

Who knew? DNA.

A female bumble bee, Bombus fervidus, heads for a purple coneflower. (Photo by Kathy Keatley Garvey)
A female bumble bee, Bombus fervidus, heads for a purple coneflower. (Photo by Kathy Keatley Garvey)

A female bumble bee, Bombus fervidus, heads for a purple coneflower. (Photo by Kathy Keatley Garvey)

Bombus fervidus atop the purple coneflower. (Photo by Kathy Keatley Garvey)
Bombus fervidus atop the purple coneflower. (Photo by Kathy Keatley Garvey)

Bombus fervidus atop the purple coneflower. (Photo by Kathy Keatley Garvey)

Posted on Wednesday, June 18, 2014 at 5:28 PM

Boys' Night Out

By day, they fly around our yard looking for the girls.

At night, it's "Boys' Night Out."

These males, longhorned digger bees, Melissodes agilis (as identified by native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis), are absolutely spectacular.  At night the males roost on our lavender stems, sometimes 8 to 10 on a single stem.  Their "bedroom" gets quite crowded.

Melissodes are ground-nesting solitary bees. While the males sleep overnight on the flowers, each female is tucked away in her ground nest.

According to the Discoverlife.org: "With the apparent exception of Florida, agilis occurs throughout the United States, Southern Canada and Northern Mexico, and is in flight from May to November in the East."

Christopher O'Toole and Anthony Raw write in their book, Insects of the World, that Melissodes are found on all continents except for Australia. "The males of nearly all species have very long antennae and are colloquially known as 'longhorned bees.'"

These bees frequent plants of the sunflower family, Helianthus. In our yard, they gravitate toward the blanket flowers (Gallardia) and Mexican sunflower (Tithonia).

We've found them "going to bed" at 6 p.m. and rising around 7 a.m. We clocked one "sleepy head" getting up at 10:30 a.m. as honey bees and bumble bees buzzed around him, foraging for nectar on the lavender.

That was on Sunday, Father's Day.

These males are longhorned digger bees, Melissodes agilis, sleeping on a lavender stem. (Photo by Kathy Keatley Garvey)
These males are longhorned digger bees, Melissodes agilis, sleeping on a lavender stem. (Photo by Kathy Keatley Garvey)

These males are longhorned digger bees, Melissodes agilis, sleeping on a lavender stem. (Photo by Kathy Keatley Garvey)

A male longhorned bee, Melissodes agilis, stirs after the warmth of the sun awakens him. (Photo by Kathy Keatley Garvey)
A male longhorned bee, Melissodes agilis, stirs after the warmth of the sun awakens him. (Photo by Kathy Keatley Garvey)

A male longhorned bee, Melissodes agilis, stirs after the warmth of the sun awakens him. (Photo by Kathy Keatley Garvey)

Side view of male longhorned bee, Melissodes agilis. (Photo by Kathy Keatley Garvey)
Side view of male longhorned bee, Melissodes agilis. (Photo by Kathy Keatley Garvey)

Side view of male longhorned bee, Melissodes agilis. (Photo by Kathy Keatley Garvey)

Posted on Monday, June 16, 2014 at 9:52 PM

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