After the Rains, Tiny Rainbows

After the rains come the butterflies.

As wildflower blooms explode across Southern California, they attract colorful swarms of painted ladies, fueling the insects' population boom.

The orange-speckled butterflies are invading lush gardens and open fields, from the region's inland valleys to the high deserts, where they feed and breed as they make their annual spring journey from Mexico.

"This could be the largest migration in history," thanks to record-breaking rains and the desert blooms they produced, said Greg Ballmer, an entomology research associate at UC Riverside.

There are millions, probably tens of millions of butterflies this year, said David Marriott, director of the Monarch Program in Encinitas: "It's a population explosion."

Such a phenomenon occurs about twice every decade, as the painted ladies flit in a steady stream along the Southern California coast and through desert and mountain passes toward the Pacific Northwest, Marriott said. The swarms usually disperse once they reach Santa Barbara, although some butterflies will travel as far as Oregon and Canada.

The orange, black and white-spotted creatures fly roughly 15 to 20 mph, said Julian P. Donahue, former curator of lepidoptera at the Natural History Museum of Los Angeles County, and assistant secretary of the Lepidopterists' Society. They feed on nectar from thistles and wildflowers along the way -- if scrub jays or speeding Escalades don't get them first.

In recent weeks, security guard Brian Hightower has sat in his air-conditioned booth outside the Huntington Botanical Gardens and watched throngs of painted ladies flutter by.

"I'm fascinated by them," Hightower said, proudly adding that the San Marino location was in the butterflies' migration path.

The painted ladies started showing up after the last major rainstorm, he said.

"The hotter it got, you could just see about 1,000 per minute for 200 yards," he said.

In San Bernardino, Dave Goodward's fifth-grade science class lined up across a sunny ball field earlier this week, counting -- and occasionally chasing -- the butterflies.

"I got one! I got one!" hollered one of his students from Kimbark Elementary School, adding another catch to his class' unofficial butterfly census.

Painted ladies are a common sight in the heavily traveled Cajon Pass, where Interstate 15 snakes into the desert, but have not caused any problems, said Tony Nguyen, a San Bernardino-based Highway Patrol officer.