How times change with the advancement of knowledge.

It's long been known that when honey bees—as well as other insects—get trapped in the milkweed's pollinia, or sticky mass of pollen, many perish when they are unable to free themselves.

So when we were perusing the book, ABC of Bee Culture, published in 1890 and written by noted beekeeping innovator/entrepreneur A. I. Root (1839-1923) of Ohio--with information “gleaned from the experience of thousands of beekeepers from all over the land”--we came across a surprising recommendation.

The surprising recommendation: If you want to kill off bees where they are not wanted, plant milkweed. In one reference, milkweed is described as a “useless weed.” (Actually, it's the only larval host of the monarch butterfly and without milkweed, no monarchs.)

Excerpt from ABC of Bee Culture:

"Milkweed (Asclepias cornuti). This plant is celebrated, not for the honey it produces, although it doubtless furnishes a good supply, but for its queer, winged masses of pollen, which attach themselves to the bees's feet and cause him to become a cripple, if not to lose his life. Every fall, we have many inquiries from new subscribers in regard to this queer phenomenon. Some think it is a parasite, others a protuberance growing on the bee's foot, and others, a winged insect enemy of the bee.” (Note that foragers are referred to as male, but all foragers are female.)

“It is the same that Prof. Riley alluded to when he recommended that the milkweed be planted to kill off the bees when they become troublesome to the fruit grower. The folly of such advice—think of the labor and expense of starting a plantation of useless weeds just to entrap honey bees---becomes more apparent when we learn that it is perhaps only the old and enfeebled bees that are unable to free themselves from those appendages, and hence the milkweed can scarcely be called an enemy. The appendage, it will be observed, looks like a pair of wings, and they attach themselves to the bee by a glutinous matter which quickly hardens so it is quite difficult to remove, if not done when it is first attached.”

There's a wealth of information in the encyclopedic ABC of Bee Culture, even the 126-year-old edition, but planting milkweed to kill bees and describing milkweed a "useless weed" aren't two of them.

How times change with the advancement of knowledge.

(Editor's Note: The newest edition of the ABC of Bee Culture is The ABC and Xyz of Bee Culture: An Encyclopedia of Beekeeping, 40th Edition. It's published by the A. I. Root Co.)

Do they ever slow down?

Not much.

The male European wool carder bee (Anthidium manicatum), a yellow and black bee about the size of a honey bee, spends most of the day defending its "property" (food) from other visitors. It's so territorial that it will dive-bomb and/or bodyslam visitors such as honey bees, butterflies, sweat bees, carpenter bees, bumble bees and praying mantids that dare land on or occupy "their" plant. We've seen them do this on catmint, blanket flower, Mexican sunflower, foxgloves and bluebeard.

If you're a floral visitor, it's no fun trying to sip some nectar while trying to dodge a yellow-and-black bullet. And if you don't move, you're likely to get hit. Unexpectedly.

Early morning, however, is a perfect time to photograph the male carder bees. They're often resting on a blossom, warming their flight muscles, or sipping a little nectar.

The bees, so named because the females collect or "card"  leaf fuzz for their nests, were introduced in New York in 1963, and then began spreading west. They were first recorded in California (Sunnyvale) in 2007.

"Males are considerably larger than females, and have a spine on either side of the last two abdominal segments and three spines on the last segment," says Lynn Kimsey, director of the Bohart Museum of Entomology and a professor of entomology at UC Davis. Those spines have been mistaken for stingers, but only females have stingers.

The female wool carder bees build their nests in rotting wood or preexisting tunnels, such as beetle burrows, Kimsey says. At night, we've seen the males sleeping in the bee condos (drilled blocks of wood) meant as homes for blue orchard bees. 

A little R&R before D&B (dive-bombing and body-slamming).

(Note: Check out the Anthidium manicatum research in  Pan-Pacific Entomologist, the work of entomologist Tom Zavortink, associate at the Bohart Museum of Entomology, UC Davis, and entomologist  Sandra Shanks, formerly of Davis and now Port Townsend, Wash. They pointed out that several papers “have documented its spread from neighboring areas in the northeastern United States and southern Canada” and that the species has since crossed the country. It was confirmed in Colorado in 2005, Missouri in 2006, and Maine, Michigan, Maryland and California (Sunnyvale) in 2007, the entomologists wrote.)

So here's this tiny praying mantis hovering over a spider's web in the bluebeard (Caryopteris clandonensis) in our pollinator garden. In the web are freshly caught prey, including a honey bee.

Now the praying mantis is known for snatching and devouring live prey--but this one appeared to be contemplating leftovers. Leftovers? Yes, and quite-dead leftovers.

Praying mantids don't do leftovers. They do eat their brothers and sisters, though, when they emerge from the ootheca. All's fair in love and war when prey is at a premium.

But this inch-long "bluebeard predator" appeared fairly new to the game of "snatch, hold and eat." Bees buzzed around his head but he kept looking down, looking for victims.

Which brings to mind a meme that friend Darren McNabb developed and posted on his popular Facebook page, Darren's Bugs. McNabb, who lives in Coralville, Iowa, is a talented macro photographer and life-long entomology enthusiast. He rears a few praying mantids. And he has a great sense of humor.

Ever been puzzled about what to call the key anatomical parts of a praying mantis?

Well, not to worry. Darren McNabb has them all figured out.

• The antennae: "Booty detectors."
• The eyes: "Victim locators."
  
• The mouth: "Devourer of all things, possibly including time"
  
• Those spiked forelegs: "Double-spined murder clamps."

Then there are the "neck enlongeners" and the "holder-uppers" and "floppy surprises."

The last time we saw our little praying mantis, he was using his "booty detectors," "victim locators" and "neck enlongeners," but not his "holder-uppers" or "double-spined murder clamps."

Thanks, Darren. You nailed it!

Yellow-faced bumble bee, Bombus vosnesenskii, heading toward a California golden poppy. (Photo by Kathy Keatley Garvey)

How it all began: Pollination ecologist Neal Williams, associate professor in the UC Davis Department of Entomology and Nematology and postdoctoral researcher Rosemary Malfi set out to research how the short-term loss of floral resources affects bumble bees,  specifically the yellow-faced bumble bee, Bombus vosnesenskii, a common bumble bee native to the West Coast of the United States. Its importance to agriculture, including the pollination of greenhouse tomatoes, cannot be overstated.

So, "the bee team," led by Williams, decided they needed to weigh the bees as part of their research. They engaged mechanical and electrical engineers on the UC Davis campus to see if they could come up with a "bee scale" to weigh individual foragers.

They could and they did. The project is underway in a field west of the central UC Davis campus. The site includes fine-mesh tents filled with wildflowers to contain the bumble bees and an RV converted into a lab.

Fell began his piece with "How do you weigh a bee?"

"That's the question that brought together insect specialists at the University of California, Davis, and two teams of UC Davis engineering students this year, to try and solve what turns out to be a tricky technical problem," Fell wrote. "But the consequences are important: ultimately, understanding how California's native bumble bees respond to changes in the environment and the availability of flowers, and how we can protect these insects that are so vital to both agriculture and wild plants."

The entomologists worked with electrical engineers Anthony Troxell, Jeff Luu and Wael Yehdego, advised by Andre Knoesen, professor in the Department of Electrical and Computer Engineering, and mechanical engineers Lillian Gibbons, Laurel Salinas and Ryan Tucci, advised by Professor Jason Moore.

Fell wrote: "The electrical engineers had to solve the problem of taking the raw signal from the scale and obtaining time-stamped data for individual bees."

“We were working with very small signals, at the low end of the technology, so noise in the data was an issue,” Troxell related in the news story. "A bumble bee weighs between 150 and 200 milligrams, and to get useful information about bee health or how much pollen they are carrying, the scale would need to be accurate to less than one milligram. A conventional laboratory balance averages several readings over a few seconds — but bees are much too fast and jittery for that to work."

Williams described the bee scale as "a great example of interdisciplinary work." And indeed it is.

This project is sure to gain national and international attention. It's not just about the plight of the bumble bees but the unique collaboration between entomologists and engineers and the resulting device they successfully designed and crafted.