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Native bee forage: European centaury

Sometimes “it takes a village” just to identify a plant. I had been struggling with this one since last summer after I photographed a perfect little native bee sampling it in the Capitol Forest. I was so intent on capturing the bee, I completely forgot to photograph the rest of the plant or take a sample.

Last week I finally sent the photo to a friend who doggedly pursued an identification. Based on where it was growing—disturbed areas along dry, sunny roadsides—we believed the plant was probably an introduced species. Sure enough, when the mystery was solved, our theory held.

The plant, Centaurium erythraea of the Gentian family, is native to Europe, parts of northern Africa, and western Asia. But due to its popularity as a medicinal herb, it has spread across the globe. In North America it has naturalized on the east coast from the Province of Québec to Georgia, and on the west coast from British Columbia to California. It is also common in Australia.

Commonly known as European centaury or common centaury, the plant is a biennial herb with a basal rosette of leaves and opposite triangular leaves along the main stem, non of which you can see from my photo. In Europe, the herb is used as a tea and thought to help with digestive problems.

I found no information on the composition of nectar or pollen, but the little native bee in the photo is loaded with brilliant yellow pollen. Several of these bees were working the flowers at the time I took the photos in July and they certainly seemed happy with their find. In Europe the plant is known to be visited by hoverflies, bees, moths, and butterflies (Brys and Jacquemyn 2011) but it can self-pollinate with good results as well (Ubsdell 1979).

Thank you mbee for solving the puzzle.

Rusty
HoneyBeeSuite

European centaury blooming in July.
European centaury blooming in July.
European centaury with small native bee.
European centaury with small native bee.

Pollen tramps I have known: Isabella

When I began my search for the trampiest ladies in town, the bees sent me to a stand of thistle adjacent to the appaloosa club. The thistle, standing prickly and purple in the morning sun, was asparkle with snow-white pollen—a rich spread for butterflies, beetles, and bees.

It was on one of those spiky flowers that I met Isabella. At first, I thought she was a little bumble bee, but now I’m not so sure. The surfeit of pollen was concealing her true colors, and what I thought was a white face may have been only crumbs from a hastily gathered cache of pollen or nectar.

Isabella frolicked in the thistles, diving head first into the petals, tail in the air, then resurfacing briefly only to dive again. I see no pollen baskets which makes be think she may be a he out for a morning sip of nectar. Or the bee may be another species altogether . . . I simply don’t know. In any case, s/he is my first candidate for pollen tramp of the year, basking in messiness like a kid with a popsicle.

Rusty
HoneyBeeSuite

Native bee on thistle in the Capital State Forest.
Native bee on thistle in the Capital State Forest.

Alkali bees face death by highway

The Touchet Valley in eastern Washington is home to the largest population of managed alkali bees anywhere on earth. If you have never met an alkali bee, Nomia melanderi, they are solitary, ground-dwelling bees in the family Halictidae. Native to North America and smaller than a honey bee, they have bands of blue, green, or orange across their abdomens. They like to live in dense communities, digging their homes in stretches of salty earth that is virtually free of foliage and roots.

According to Bees of the World (O’Toole & Raw 2004) alkali bees naturally build about 500 nests per square meter. But when farmers tend the soil and maintain just the right combination of texture and moisture, the bees can be coaxed into building 2000-3000 nests per square meter.

That is exactly what farmers have done for years in the Touchet Valley. Alfalfa growers in the area manage over 120 acres of alkali bees that pollinate nearly 12,000 acres of alfalfa. The alkali bees boost alfalfa seed production by as much as 70 percent.

But all that is about to change because the Washington State Department of Transportation plans to move and widen the part of Highway 12 that borders the nesting area. Not only will the road width be expanded into a four-lane divided format, but the relocation will put the road right through the bees’ flight path.

A four-year study now underway shows that the bees fly just one to three feet off the ground, so mass slaughter is in store unless an alternative can be found. Researches from Washington State University erected mesh fences to see if they could get the bees to fly higher across the road, but the bees went up and over like pole vaulters, resuming the same altitude as soon as they crossed.

A range of other possibilities are being explored, but so far no answer has been found. See the complete story in The Seattle Times, “Farmers worry that road project will turn productive bees into roadkill.”

Rusty
HoneyBeeSuite

Alkali bee pollinating alfalfa. Photo by Douglas Walsh/WSU Prosser Irrigated Agriculture Research and Extension Center.
Alkali bee pollinating alfalfa. Photo by Douglas Walsh/WSU Prosser Irrigated Agriculture Research and Extension Center.

The logistics of pollen

All bees have one thing in common: they use pollen and nectar to feed both themselves and their young. However, the best way to bring pollen and larvae together has been a subject of disagreement among bee species. As a result, bees have devised various ways to solve the age-old problem.

When we think of bees and pollen we usually visualize chunky pollen pellets adhering to the hind legs of a foraging bee. But in fact, certain members of the Apidae family—including bumble bees, honey bees, orchid bees, and stingless bees—are the only ones that have corbiculae (pollen baskets).

Many bees have a scopa somewhere on their bodies. A scopa is a tuft of specialized hairs that are designed to hold pollen grains. Many mining bees, for example, have scopae on their hind legs. In some species, the leg scopa is on the tibia, but in others the leg scopa is higher up on the femur. Some species of the Colletes and Andrena genera have additional scopae on the sides of the thorax in an area called the propodeum.

Going further, some bees in the Fideliidae and Megachilidae families have a pollen scopa on the undersides of their abdomens. This is commonly seen in the mason bees.

Some species in the Colletidae family (subfamily Hylaeinae) have no scopae or corbiculae anywhere. Instead, they swallow the pollen in their crops and regurgitate it much like nectar.

Then, of course, some bees have decided not to carry pollen at all—they just steal it. Instead of bringing the pollen to the larvae, they bring the larvae to the pollen. To achieve this, they invade the home of another bee and deposit their eggs on the pollen provision left by the host bee for her own offspring. These social parasites, known as cuckoo bees, are found in various families and, over time, have lost all ability to carry pollen. Cuckoos are more numerous than you might think; O’Toole and Raw in “Bees of the World” estimate that 20 percent of North American bees are cuckoos.

Rusty
HoneyBeeSuite

I found this little bee yesterday in the Capital State Forest. Notice the tufts of hair on her hind leg.
I found this little bee yesterday in the Capital State Forest. Notice the tufts of hair on her hind leg.

Lions and tigers and bears, oh my

As I knelt beside a Ceanothus, eager to photograph bumble bees, I was distracted by a little black fly. But when the tiny creature bustled into my field of view, I was amazed to see not a fly, but a bee. She was fully formed with all the signs that, taken together, indicate bee-ness: double wings, bent antennae, five eyes, and two loads of pollen.

The little creature was no bigger than a thought—a mere wanna bee. She could have walked beneath a honey bee’s belly with an umbrella. It was love at first sight. I called her Lolita.

I don’t have the equipment or the skill to photograph such an imp of perfection, but I kept hitting the shutter anyway. How could something so small have so many features? Lolita was built like the iPhone of the future.

The incident got me thinking about pollinator conservation. Nearly all the press—and therefore all the conservation money—benefits large furry mammals with doleful eyes or great teeth: lions, tigers, polar bears, rhinos, and whales. Even in the invertebrate world, our attention is riveted on bulky bumble bees or rakish butterflies, as if something big is more important than something small, as if largeness is its own virtue.

Meanwhile, we are out there poisoning everything in sight and lots of things that aren’t. If toxins in our environment are harming Hymenopterans as large as honey bees, think what they must be doing to this figment of a bee. She’s pollinating her heart out for us while we don’t give a damn. We’re killing things we don’t even know exist and the waste is staggering.

To the best of my limited knowledge, my little bee is an Andrena or mining bee. According to “Bees, Wasps, and Ants” by Eric Grissell (2010), about 1500 species of these live in North America alone. She was about a quarter of an inch long and carried two loads of pollen that looked like saddle bags on a motorcycle. Before long she was joined by other Lolitas—all perfect and all perfectly amazing.

Rusty
HoneyBeeSuite

Everything a bee needs to be.
Everything a bee needs to be.