Sometimes you get lucky.
While watching floral visitors foraging last week in our rock purslane (Calandrinia grandiflora), we noticed a tiny black bee, something we'd never seen before.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at the UC Davis Department of Entomology, identified it as a female leafcutting bee, Megachile gemula, "which has an all-black form."
It's a rather uncommon bee, but a distinctive bee, said Thorp, who is one of the instructors of The Bee Course, offered every year in the Southwestern Research Station, Portal, Ariz., for conservation biologists, pollination ecologists and other biologists who want to gain greater knowledge of the systematics and biology of bees. Participants come worldwide to learn about bees.
Megachile gemula is native to the United States. The females snip round holes in leaves and line their nests with the material. From egg to larva to pupa, a new generation emerges from the sealed nest.
Meanwhile, if you want to go on a walking tour with Thorp, mark your calendar for Friday, June 22. Thorp will lead a Tahoe National Forest Service tour of native plants and pollinators in the Loney Meadow, near Nevada City, Nevada County. The tour, free and open to the public, will take place from 10 a.m. to approximately 2 p.m.
The walk is provided as part of the Forest Service Pacific Southwest Region’s 2012 Pollinator Special Emphasis Area "which has been developed to call attention to the importance of butterflies and native bees in providing important services for food production and ecosystem health," said Kathy Van Zuuk, Yuba River Ranger District botanist and forest level non-native invasive plant coordinator.
And what bees might tour participants encounter? Probably bumble bees, mining bees, digger bees, leafcutting bees, mason bees and cuckoo bees, Thorp said. Other floral-visitors are expected to include flies, butterflies, and beetles, he said. Van Zuuk and fellow botanist Karen Wiese will identify the native plants.
Those interested should meet at 10 a.m. at the Sierra Discovery Trail parking lot located off Highway 20 to carpool to Loney Meadow (where parking is limited). Participants of all ages should bring water, snacks, insect repellent, sunscreen and wear suitable footwear. (No dogs, please.)
Further information is available by contacting Van Zuuk at (530) 478-6243 or emailing her at firstname.lastname@example.org.
First you give them roots, then you give them wings.
That's what's happening in our bee condo, a wooden block (nest) with drilled holes for leafcutting bees (Megachile).
They flew in, laid their eggs, provisioned the nests with pollen and leaf fragments, and capped the holes.
We had 11 tenants. Now there's a hole in one.
Success! A leafcutting bee emerged. Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, says that "Some leafcutting bees, especially the introduced ones like the alfalfa leafcutting bee, have more than one generation per year. Bees of the second and third generation may clean out or partly clean out old nest holes like this and construct a new nest inside. Sometimes you can find new leaf material inside the old cocoon of the previous nest builder. Thus, the tunnels get smaller in diameter with succeeding generations. Kind of like the build up of old cocoons in honey bee comb and resulting smaller inner diameter of the brood cells in old dark comb."
It's all rather exciting being a "beekeeper." We've never had a hole in one--'til now.
If you, too, want to keep native bees, Thorp has compiled a list of where you can buy homes for them or where you can learn how to build your own. The list is on the Harry H. Laidlaw Jr. Honey Bee Research facility website.
You can also buy them at beekeeping supply stores.
Now that we have a hole in one, 10 tenants to go...
That's how many tenants are occupying our wooden bee block, aka "bee condo."
It's "home, sweet home" for leafcutting bees (Megachile spp.).
Daily we see these native bees tear holes in leaves (red bud, rose, catmint, gold coin, rock purslane and nectarine) and gather the fragments to line their nests.
Folks who grow prize-winning roses--the kind that win blue ribbons at county fairs and rose shows--aren't fond of these little critters, but we are.
Especially when we see two leafcutters at the bee condo at the same time...
Leafcutter bees (Megachile spp.), so named because they cut leaves and petals to line their nests, are smaller than the honey bees but move faster. These native bees are easily recognizable by the black-white bands on their abdomen.
Catching them in flight requires a lot of patience.
We watched one leafcutter bee dart from catmint flower to catmint flower (Nepeta). It is 2 p.m. One movement of the camera and off it goes. One step toward it and it takes flight. A shadow over it and it vanishes.
This one (below) managed to maneuver around carder bees, honey bees, carpenter bees, assorted butterflies, a curious cat determined to sample the catmint, and a persistent spider that cunningly wove its web right between two stems.
Finally, it overcame all the obstacles for its reward: a long sip of nectar.
The cold, blustery storm that swept over Northern California over the last two weeks wiped out the rock purslane (Calandrinia grandiflora) and with it the "meeting place" of assorted insects: honey bees, leafcutter bees, ladybugs, bumble bees, potter wasps, et al.
But last August we spotted a male leafcutting bee, Megachile sp., on the rock purslane. Nearby, a redbud tree showed evidence of a "been there-done that" female leafcutter. She had trimmed a little off the edge of the leaf for her solitary ground nest. Leafcutter bees, as their name implies, cut leaves for their nests.
That's a good sign.
It is so important to provide bee friendly gardens for our pollinators, such as honey bees, bumble bees and leafcutter bees. Their survival, in many ways, depends on us.
To encourage them, plant bee friendly gardens, provide nesting sites and refrain from using pesticides.
Speaking of native bees, leafcutting bees are among those featured on the soon-to-be-mailed calendar sponsored by the non-profit Xerces Society and the Great Sunflower Project and assembled by Bay Area native bee enthusiast Celeste Ets-Hokin, with photographs by entomologist-insect photographer Rollin Coville, also of the Bay Area. The deadline to order the native bee calendar closed Nov. 30 (however, a few--a very few--may still be available from the sponsors).
Meanwhile, those of who us treasured the native bees in our gardens last spring and summer will treasure this calendar all year around.
This is a bee that cuts it.