THE CALIFORNIA GARDEN - Brilliant winged giants - Swallowtails, once rare here, are making a splendid showing.

Even in one of the driest years on record and an "awful" one for butterflies, according to Fred Heath, author of "An Introduction to Southern California Butterflies," giant swallowtails are fairly easy to spot, particularly in neighborhoods where citrus is common.

"Because it feeds on evergreen trees," says Brent Karner, associate manager of entomological exhibits at the Natural History Museum of Los Angeles County, "it's not as dependent on rainfall as other species. It's one of the few butterflies we've seen right through this dry year."

The giant swallowtail, once rare in these parts, is now well-established in Southern California. Its funny-looking larvae, known as "orange dogs," feed on citrus and other members of the rue family. But gardeners needn't worry, and wild lands aren't threatened.

Orange dogs dine singly, not in packs, and do minimal damage to mature citrus trees. Native-plant specialists haven't seen them in the wild, where larval food plants are virtually nonexistent.

Butterfly enthusiast Bruce Steele is thrilled that giant swallowtails have at last found his oak-shaded Altadena garden. He darts among trees, searching for giant swallowtail eggs (minuscule) and caterpillars -- some smaller than rice grains -- on odorous rue plants that he grew solely to attract egg-laying adults.

"I had a book about them when I was a child," he says. "I guess I'm still a kid at heart."

The giant swallowtail butterfly, Heraclides (Papilio) cresphontes, is native to the Southeast. Since the 1960s, populations have spread west following a corridor of suburban development and the species' favorite larval food source -- citrus -- through Arizona, into the Imperial Valley, then San Diego and north to Orange and Los Angeles counties. They've been sighted as far north as Santa Barbara and Bakersfield.

Numbers have surged since 2000, says Jess Morton, president of the Palos Verdes-South Bay chapter of the Audubon Society. Members have held a butterfly count at the same location, on the first Sunday in July, every year since 1991. According to their records, a single giant swallowtail was first seen in the South Bay in 2000. They counted 23 in 2007.