It's commonly called a "passion butterfly," but we call it a Gulf Fritillary (Agraulis vanillaea) or Gulf Frit.

Or "spectacular."

A sure sign of autumn:

• A skeletonized passionflower vine (Passiflora)
• A Gulf Fritillary (Agraulis vanillae) eclosing
• A ravenous caterpillar crawling along a stem, and
• A caterpillar J'ing, about to form a chrysalis.

The orange-reddish butterfly, with its silver-spangled underwings, is a glorious butterfly.

How's the population doing this year?

Butterfly guru Art Shapiro, UC Davis professor of evolution and ecology, who has monitored the butterfly populations of central California for more than four decades and posts his research on Art's Butterfly World, says this year the Gulf Frit population is "spotty; locally abundant but less generally distributed than in recent years."

His 10 field sites stretch from the Sacramento River Delta through the Sacramento Valley and Sierra Nevada mountains to the high desert of the Western Great Basin.

We notice the ups and downs of the Gulf Frit population every year in Vacaville. This spring they were slow to start, Western scrub jays and European paper wasps grabbed what few caterpillars there were. In the summer, the population speeded up.  And now caterpillars and chrysalids cover two of our three vines--or what's left of our three vines.

Shaprio says the Gulf Frit was introduced into southern California in the 19th century, in the vicinity of San Diego in the 1870s. It was first recorded in the Bay Area before 1908. "It became a persistent breeding resident in the East and South Bay in the 1950s and has been there since." Once prevalent in the Sacramento area in the 1960s, it "seems to have died out by the early 1970s," he said.  Then in 2009, it began making a comeback in the Sacramento area.

Meanwhile, the passionflower vine climbs our fences with reckless abandon, only to be skeletonized by the growing population of Gulf Frits. They eat the leaves, the flowers, the fruit, and then start in on the bark.

More Gulf Frits mate. More eggs, caterpillars, chrysalids and adults appear. The cycle continues until the first frost. The plants die back, and will recover in the spring. A few chrysalids will remain, clinging to the vines like leftover Christmas tree ornaments,

Surprises occur. Several years ago, we saw a Gulf Frit laying an egg on Christmas Day.

Where are you, Gulf Fritillaries?

The Gulf Fritillary (Agraulis vanillae) population seems to be diminishing this year around Solano and Yolo counties.

A few here, a few there, but not in the large numbers of last year.

Last summer the Gulf Frits overwhelmed our passionflower vine (Passiflora), their host plant, and skeletonized it.

Which is what we want them to do. We plant Passiflora for them, not for the fruit or the blossoms.  On a good year, they eat it all--blossoms, fruit, leaves and stems--and look for more.

The history of the butterfly in California is as striking as its silver-spangled, reddish-orange coloring.

“It first appeared in California in the vicinity of San Diego in the 1870s,” says noted butterfly expert Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis. “It spread through Southern California in urban settings and was first recorded in the Bay Area about 1908. It became a persistent breeding resident in the East and South Bay in the 1950s and has been there since.”

Shapiro, who has monitored butterflies in central California since 1972 and maintains a research website at http://butterfly.ucdavis.edu,  says the Gulf Frit “apparently bred in the Sacramento area and possibly in Davis in the 1960s, becoming extinct in the early 1970s, then recolonizing again throughout the area since 2000.”

It's making a comeback, but this year it doesn't seem to be "coming back" so much.

Want to attract the Gulf Frit? Plant its host plant and some of its favorite nectar plants. In our pollinator garden in Vacaville, their favorite nectar sources include the butterfly bush (Buddleia), Mexican sunflower (Tithonia) and lantana (genus Lantana.)

Plant them and they will come--if they're around!

Sometimes there's a method to our madness, or madness to our method.

Take the silver-spangled, orange-reddish butterfly, the Gulf Fritilllary (Agraulis vanillae).

We spotted a female dive-bombing her host plant, the passionflower vine (Passiflora) in our pollinator garden in Vacaville. She circled, dipped, soared, and dipped again. She flew upside down, and right side up.

Ah, a photographic challenge!

We managed to catch her in flight, using a Nikon Z7 mirrorless camera mounted with a 105mm Nikon lens. We set the shutter speed at 1/3200 of a second to freeze the action. Other settings: f-stop of 5.6, and ISO of 250.  

Then we focused on the area where we thought she'd be. Look where she's going, not where she's been!

And what a gorgeous butterfly and what a beautiful ballet! Finally, she laid some eggs on the tendrils and leaves and vanished.

Butterfly guru Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis, says the Gulf Frit was introduced into southern California in the 19th century, and was first recorded in the Bay Area before 1908. Once prevalent in the Sacramento area in the 1960s, it "seems to have died out by the early 1970s."

Then in 2009, the Gulf Frits began making a comeback in the Sacramento area.

This year the sightings are rather slow, but one butterfly ballet--just one--brings back the wonder of it all.

"The butterfly counts not months but moments, and has time enough."--Rabindranath Tagore

 When we think of orange and autumn, we think of the marriage of the Gulf Fritillary (Agraulis vanillae), and the Mexican sunflower (Tithonia).

The silver-spangled Gulf Fritillary, a showy orange butterfly, looks like two different species. When it spreads its wings, it's orange. The underwings: silver.

"Dazzling," agrees butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology.

"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," he says on his website.

"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."

The Gulf Frit bred in Sacramento in abundance on Passiflora in the early 1960s, Shapiro relates. "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!"

Its host plant: Passiflora or passionflower vine. Plant it and they will come (at least in this area)!

"Happiness is a butterfly, which when pursued, is always just beyond your grasp, but which, if you will sit down quietly, may alight upon you."--Nathaniel Hawthorne