When you visit the Häagen-Dazs Honey Bee Haven on Bee Biology Road, University of California, Davis, be sure to check out the passionflower vine clinging to the fence.
You'll see female Valley carpenter bees (Xylocopa varipuncta) seemingly speckled with gold dust. This is actually a thick coat of pollen from their foraging ventures. Underneath that gold pollen, the females are a solid black. (The males of this species are blond with green eyes.)
One of the haven's founding volunteer gardeners, Mary Patterson, a retired cattle rancher and businesswoman who was honored in 2009 as a "Friend of the College" (UC Davis College of Agricultural and Natural Resources), planted the vine there.
The vine is doing quite well.
So are the carpenter bees.
Passionflower blossoms range in color from white to lavender to red, depending on the varieties. This one sports lavender blossoms.
Passiflora is the larval host plant of the Gulf Fritillary butterflies, Agraulis vanillae, a showy reddish-orange butterfly nicknamed "The Passion Butterfly." We spotted no eggs, caterpillars or chrysalids on this particular vine, however.
The Häagen-Dazs Honey Bee Haven, planted in the fall of 2009, provides a year-around food source for the nearby bees at the Harry H. Laidlaw Jr. Honey Bee Research Facility and other pollinators. It also serves to raise public awareness on the plight of honey bees, and as an educational resource to help visitors decide what to plant in their own gardens.
Maintained by the UC Department of Entomology and Nematology, it's open year around, from dawn to dusk for self-guided tours. Admission? Free. But if you want a guided tour, there's a nominal fee of $3 per person. For more information, contact Christine Casey at email@example.com.
University of Minnesota honey bee researcher Marla Spivak, in her TED talk on honey bee health, referred to bees as "flower feeders."
That they are. Flower feeders.
As are other pollinators from butterflies to beetles to bats.
But it's a special treat to see butterflies, honey bees and carpenter bees sharing blossoms of the same plant, the passionflower vine (Passiflora).
Several years ago a UC Davis professor planted a fenceline of passionflower vines at her residence off east Covell Boulevard, Davis. This year she is reaping her reward: Gulf Fritillaries (Agraulis vanillae), honey bees and Valley carpenter bees are all over it. Why Gulf Frits? The passionflower vine is their host plant. You can see the entire life cycle from egg to caterpillar to chrysalis to adult in her yard.
The Valley carpenter bees (Xylocopa varipuncta) are frequent foragers, too. The females frighten many people because of their size and loud buzz. They're a solid black, in sharp contrast to the males, which are golden with green eyes.
We didn't see one predator Thursday in her Davis yard.
In our yard, we have scores of predators on our passionflower vines: scrub jays, European paper wasps, jumping spiders, ladybugs, assassin bugs and an occasional praying mantis. Although the jays pick off the caterpillars from our passionflower vines, they don't seem to go for the adults.
Butterfly expert Art Shapiro, distinguished professor of evolution and ecology at UC Davis, points to research published in a 2007 edition of the Journal of Chemical Ecology that indicates that the Gulf Fritillary adults are poisonous to birds. A team of scientists from Maryland, Virginia and Georgia wrote in the abstract of their article, “Novel Chemistry of Abdominal Defensive Glands of Nymphalid Butterfly (Agraulis vanillae): “Abdominal defensive glands of both sexes of the Gulf Fritillary butterfly, emit a pronounced odor when disturbed…we suggest that the constituents in the glands may play a defensive role against potential avian predators.”
The article relates that Linnaeus (1758) first described the tropical butterfly and noted that its brilliant coloration of the reddish-orange butterfly makes it conspicuous.
Valley carpenter bees are passionate about passionflower vines (Passiflora).
You see these black bees foraging on the blossoms. Tiny grains of golden pollen, looking like gold dust, dot the thorax.
Their loud buzz frightens many a person, but wait, they're pollinators.
Valley carpenter bees (Xylocopa varipuncta) are found in the Central Valley and southern California, Arizona, New Mexico and southward through Mexico, according to native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis.
These carpenter bees are large (about the size of a queen bumble bee). The females are solid black, while the males are golden/buff-colored with green eyes.
We receive scores of calls about "golden bumble bees." They're the male Valley carpenter bees, sometimes nicknamed "Teddy bears."
The females are the only ones we've seen in the passionflower vines, though.
The males? They must be cruising somewhere else, patrolling for females.
Most of the time we see female Gulf Fritillary butterflies (Agraulis vanillae) laying their eggs on the leaves, and male Gulf Frits searching for females.
Call it serendipity.
Call it a prize from the sky.
Frankly, it's not every day that a newly emerged Gulf Fritillary butterfly, Agraulis vanillae, lands at your feet. It crawled from its chrysalis, hinged to a eight-foot high tree limb near our passionflower vines (Passiflora), and fell, quite unceremoniously, on a bed of wood chips.
Right where I was standing.
At first I thought a scrub jay or an European paper wasp (which keep an attentive eye on the Gulf Frit population in our yard) had nailed it.
No. This was newly emerged. It looked like a plop of red, orange and silver paint, its body limp, its antennae crumbled, its wings still damp.
I lifted it gingerly and placed it on a Passiflora to dry off. Did it fly off in five minutes? Ten minutes? Half an hour? No, it stayed for two hours. When scores of male adult butterflies ventured down to check its gender and then left, I figured it to be the same gender.
A boy butterfly.
If it were female, a male would have mated with her in minutes as one did several weeks ago when a female emerged from a chrysalis. (That, however, is not the only way you can tell gender! There are abdominal differences and males are more brightly colored, a deeper reddish-orange, than the females.)
Boy Butterfly leaned his head back, opened and stretched his wings, and finally, he took off, touching me on the shoulder as he floated by.
Butterfly expert Art Shapiro, distinguished professor of evolution and ecology at UC Davis who monitors the butterfly population in the Central Valley, is glad to see the Gulf Frits making a comeback in this area. He writes on his website:
"this dazzling bit of the New World Tropics was introduced into southern California in the 19th Century--we don't know how--and was first recorded in the Bay Area before 1908, though it seems to have become established there only in the 1950s. It can be quite common in the East and South Bay--particularly in Berkeley--and has been found breeding spontaneously as far inland as Fairfield where, however, it is not established. There are scattered records in the Central Valley and even up to Folsom, perhaps resulting from people breeding the species for amusement or to release at social occasions. According to Hal Michael, who grew up in South Sacramento, this species bred there in abundance on garden Passiflora in the early 1960s. It seems to have died out by the early 1970s, however. Intolerant of hard freezes, it still managed to survive the record cold snap of 1990 that largely exterminated the Buckeye regionally!"
As for Boy Butterfly, a loudly buzzing female Valley carpenter bee attempting to forage on a flower near his head, prompted his rather abrupt departure.
Your mother laid an egg, you hatched into a caterpillar, and you're eating as much as you can before you spin into a chrysalis and then emerge, as a butterfly, ready to start the life cycle over again.
You are not aware of the European paper wasp, its long legs dangling, moving through the leaves and eating the newly laid eggs around you. The wasp lurks in the deep, dark shadows as you finish one bite and reach for another.
Then you see the predator coming after you.
It does not end well for you. You have become protein for the wasp to feed its young.
For several weeks now, the European paper wasps (Polistes dominula) have wreaked havoc on the Gulf Frit population on our Passiflora. Sometimes they pair up in twos, sometimes in threes and fours, and once a horde of five descended
They follow the fluttering butterflies as they touch down on a leaf to lay an egg. Then they eat the eggs, kill the caterpillars, and tear apart the chrysalids.
European paper wasps are relatively new invaders from Europe; they were first spotted in the United States in 1981 in Massachusetts. They are now colonizing the entire country, taking over the native wasps' territory.
There's good news and then there's bad news. If you like having European paper wasps around to prey on the larvae of hornworms, cabbageworms and tent caterpillars, then you may consider them beneficial insects. But if you're trying to rear a few butterflies, such as the Gulf Fritillaries (Agraulis vanillae), then they're Public Enemy No. 1.
Studies show that they can also be cunning.
According to an article out of Michigan State University: "A Cornell University researcher has found that certain female wasps, without nests of their own, 'sit and wait' for an opportunity to adopt an orphaned nest or hijack a nest from another queen. These sit-and-wait female wasps prefer to adopt the most mature nests, probably because these nests will produce workers the soonest, and colonies with workers are very likely to survive. Once a queen adopts a nest she will eat the former queen's eggs and young larvae and replace them with her own eggs. The older larvae and pupae, which belonged to the former queen, are allowed to complete development and may eventually help rear the adopting female's offspring. Ferocious hunters, paper wasps feast on caterpillars."
"The nests are usually founded by a single Queen or Foundress, who starts her nest in May having hibernated as a mated queen throughout the winter often in the company of all the other mated females from their parental nest."
See photos of European paper wasps on BugGuide.net.
Meanwhile, we figure that only about 10 percent of the Gulf Frit eggs will ever make it into butterflies--no thanks to assorted predators.
But a few will make it, and what spectacular butterflies they will be!