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.)
For the last several months, we've seen monarchs laying eggs on our narrow-leafed milkweed.
A daily check yielded "zero" caterpillars. Zero. Nada. Zilch. One reason is apparent: two nearby nests of Western scrub jays filled with chirping babies. Birds aren't known for eating a large quantity of monarch caterpillars--they don't taste good--but they will still eat a few.
They didn't eat this one.
It was tucked away, hidden from sight. Then we found another caterpillar, also hidden.
In the interests of conservation--and to prevent predation--we placed them inside our indoor butterfly habitat, purchased last year from the gift shop at the Bohart Museum of Entomology, the University of California, Davis.
The rest, as they say, is history and herstory. A male eclosed from the first chrysalis, and a female from the second.
It's one of Nature's miracles. From an egg, to a caterpillar to a chrysalis to an adult Danaus plexippus.
One week, it's a hungry fifth-instar caterpillar...then it's a gold-dotted, jade-green chrysalis, a joy to see. When the chrysalis turns transparent, you can make out the colorful butterfly inside--Nature's gift that's soon to eclose.
From chrysalis to adult, the male took 10 days.
From chrysalis to adult, the female took 9 days.
We've already released the male. He soared high into the sky, at least 80 feet, and headed for an oak tree as a Western scrub jay eyed him. Whew! The predator did not pursue him.
The second monarch, the female, just eclosed this afternoon. It's Freedom Day tomorrow.
The honey bee struggled, but couldn't free herself from a broadleaf milkweed blossom in our pollinator garden. Had a predator nailed her? Or was the bee dying of natural causes? What was happening?
Two hours later we returned. The bee, now in a frenzy, was still stuck. We offered her sips of honey from a coated toothpick.
"Ah, with that flight fuel, she'll take off," we thought. She did not. Closer examination revealed her foot (tarsi) stuck in a mass of sticky pollen.
We separated the bee from her floral trap by lifting her from the gluelike pollinia with the toothpick. Off went the pollinia and off went the bee.
“If you hang around that milkweed, you might be able to get a photo of a bee carrying pollinia on its foot,” Extension apiculturist (emeritus) Eric Mussen of the UC Davis Department of Entomology and Nematology told us.
So, last weekend, armed with a camera and the memory of the frenzied bee, we waited. And waited. And waited. And got it. A bee flying off chained with golden pollinia.
Unlike most flowering plants, only milkweed and orchids produce pollinia, which is a sticky packet of golden pollen grains originating from a single anther. The wishbone-shaped pollinia are in a nectar trough where insects--or parts of them--often get trapped. This is a devious way for milkweed and orchids to force insects to “take me with you” and “help us reproduce.” If you're a small insect and/or not strong enough to loosen the grip, you'll be lodged in that sticky mass and die. It's sort of like jumping into quicksand and you can't get out. Some insects manage to escape but their parts remain. That's probably one reason why you see "amputated" bumble bees, carpenter bees, honey bees and butterflies, no thanks to the Sophisticated Reproductive Habits of the Milkweed (and Orchids).
The milkweed plant is not only the larval host--and only larval host--of the monarch butterflies, but it's a nectar source for butterflies and for many other insects--including honey bees, leafcutter bees, bumble bees, carpenter bees, syrphid flies and ants.
In fact, if you look closely at a broadleaf milkweed blossom (Asclepias speciosa), you'll see dozens of tiny pink flowers forming the umbel or umbrella-shaped structure. The corona, located on top of the petals, holds a circle of five hoods and five horns. Hoods and horns pointing the way. The hoods that hold that oh-so-sweet nectar beckon insects like a kid to a candy store. Each blossom has five vertical slits which house the reproductive organs.
So, what was happening? Ms. Honey Bee, seeking nectar for her colony, hit a sweet jackpot and repositioned herself to gather it. Then her foot slipped into one of the five sticky slits and she couldn't remove her leg.
Ms. Honey Bee survived, thanks to a human being with a toothpick. Others are not so lucky.
The more we know about monarch butterflies, the better we can understand them and help conserve them.
Newly published research on California's overwintering monarch butterflies (Danaus plexippus) confirmed many previous migratory studies, but found some unexpected and surprising patterns of movement, said lead researcher Louie Yang, a community ecologist with the UC Davis Department of Entomology and Nematology.
The study, “Intra-Population Variation in the Natal Origins and Wing Morphology of Overwintering Western Monarch Butterflies (Danaus plexippus)," published in the early online version of the journal Ecography, examined the natal origins, or “birthplaces,” of butterflies at four California overwintering sites.
It will be incorporated into an online issue, perhaps within six months, but it has not yet been assigned to an issue, said journal managing editor Maria Persson.
Natal origins of butterflies collected from the two northern sites--Lighthouse Field State Beach and Moran Lake, both in Santa Cruz County--varied significantly from those collected at the two southern overwintering sites--Pismo State Beach, San Luis Obispo County; and the Coronado Butterfly Preserve, Santa Barbara County, they said.
“We hope that this paper improves our understanding of where monarch butterflies grow up in western North America,” said Yang, an associate professor. “This study uses a naturally occurring continental-scale pattern of hydrogen isotopes in precipitation in order to estimate the natal origins of overwintering butterflies. Building a clearer understanding of where they come from could help us better understand many aspects of their ecology.”
The research is the work of Yang; Dmitry Ostrovsky of the University of Colorado, Denver; and Matthew Rogers and Jeffery Welker of the University of Alaska.
The research team set out to answer two key questions: “How do broad geographic areas of potential natal habitat contribute to the overwintering population of western monarch butterflies in California?” and “How does the individual variation in the wing morphology of overwintering western monarch butterflies correlate with estimated migratory distance from their natal origins?”
They first compared the wings of 114 monarch butterflies collected from the four overwintering sites with a continental-scale monarch butterfly wing isoscape derived from the U.S. Network for Isotypes in Precipitation (USNIP) database. They used spatial analyses of stable isotype ratios and correlations with wing morphology. Then they examined the correlations of monarch butterfly forewing size and shape.
Of the 114 butterflies sampled, they found that 30 percent developed in the southern coastal range; 12 percent in the northern coast and inland range; 16 percent in the central range, and 40 percent developed in the northern inland range.
“Interestingly, the two most northern overwintering sites in the study showed the largest contributions from the southern coastal range (Lighthouse Field, 45 percent; Moran Lake, 37 percent; Pismo Beach, 22 percent; and Coronado Preserve, 24 percent) while the two most southern overwintering sites showed the largest contributions from the northern inland range (Lighthouse Field, 30 percent; Moran Lake, 35 percent; Pismo Beach, 53 percent; and Coronado Reserve, 39 percent),” they wrote.
The researchers randomly collected the monarchs Dec. 4-6, 2009 from aggregations in trees. The collecting resulted in: 19 males and 9 females from Coronado; 22 males and 8 females from Pismo State Beach; 20 males and 10 females from Moran Lake; and 18 males and 8 females from the Lighthouse Field State Beach.
In addition, the male monarch butterflies showed mean total masses that were 5.8 percent larger than those of the females.
The monarch butterfly of North America overwinters along the California coast and in the central mountains of Mexico. Previous studies have indicated that the western monarchs or those from natal habitats west of the Rocky Mountains, overwinter along the California coast. Those that develop east of the Rockies overwinter in central Mexico.
The project was funded in part by a National Science Foundation (NSF) Early Career Development Program grant awarded to Louie Yang, and a NSF Major Research Instrumentation Program grant awarded to Jeffrey Welker.
You're yearning to see monarch eggs, caterpillars and chrysalids on milkweed. Ditto for the pipevine swallowtails on their host plant, Dutchman's pipe.
You also want some butterfly bushes and other nectar plants.
And you're thinking of replacing your drought-stricken lawn with drought-tolerant plants.
You're in luck!
"We're going to have a lot plants -- over 16,000 – including lots of Arboretum All-Stars in honor of their 10-year anniversary," spokesperson Katie Hetrick told us today.
The All-Stars are 100 specially selected plants "that have provided California with a foundation for creating attractive, easy-care landscapes that save water." A large selection of Arboretum All-Stars, California natives, and other regionally appropriate plants will be available.
The public sale offers benefits for Arboretum members, who can save 10 percent. Non-members can join at the door. For additional information, see benefits of memberships.
While you're on the campus, you can explore the 100-acre UC Davis Arboretum, a horticultural and cecreational treasure filled with scientific collections, demonstration gardens, educational information and art work. You can walk or bike the trails. Bring your camera.
If you're lucky, a monarch will flutter by./span>/span>