All aflutter

Summer begins with the appearance of the butterflies. June gloom burns off and suddenly there they are, swirling past, on their way to court, mate and frolic.

For the most enraptured gardeners, the spectacle is so thrilling that they’ve ripped out plants that they like and re-landscaped with plants that butterflies need. Where once they fought caterpillars with insecticides and thistles with weed killers, now they coddle worms and pamper weeds in an effort to nurture the splendid winged adults.

They are part of a growing breed: butterfly gardeners. For them, butterflies are more than an air show. They are a measure of the most profound seasonal tempos. No animal’s survival and habits are more directly bound up with the life of plants.

As with so many horticultural trends, butterfly gardening came out of England. It first took hold here in the early 1970s, led by the Xerces Society and the Sierra Club, says Julian Donahue, assistant curator emeritus of the Natural History Museum of Los Angeles County and for 23 years the man in charge of the moth and butterfly collection. By 1976, Donahue was publishing articles in botanical journals urging L.A.’s gardeners to create habitats.

Four years ago, these morphed into a Natural History Museum booklet, “Butterfly Gardening in Southern California” and is now the starter book for beginners. Donahue meets for an interview on a chilly, gray day that, as the calendar has it, is the first official day of summer. He expects a good show of butterflies this year, but so far, they are nowhere to be seen.

“Butterflies are coldblooded. They need heat to fly,” he says.

So we gather in the butterfly house of the museum. As he reaches for a monarch, gently gripping it by its body so it doesn’t fly away (don’t try this at home), an audience of children gather around him. They can smell a good teacher. Plus, he has what seem God-like privileges: He’s the only person who the museum staff allows to handle the insects.

“The original butterfly gardens only had nectar plants,” he says. “These are great for butterflies. But then people realized that butterflies don’t materialize out of thin air. You really have to have what the butterfly caterpillars eat.”

To know what to plant, it helps to understand the life cycle of butterflies, he says. They are first deposited onto plants as eggs, out of which hatch tiny caterpillars. The first thing an emerging caterpillar eats is its shell. It then proceeds to eat 20 times its body weight in leaves. These little “self-stuffing sausages” will shed their casings five times before it’s time to transform yet again, into pupa.

Pupa are intermediate beings, not caterpillars, not butterflies, but tightly packaged gobs of protoplasm called chrysalids. These can dangle from a plant or the eave of a house, or nestle among leaves and grass. Only the sharp eyes of entomologists, kids and predators can usually spot them: 150 million years of evolution has equipped them to look almost exactly like dead leaves. Inside, winged butterflies will be forming.

When adult butterflies first emerge from these casings, they are drowsy and damp. This is the time that they are most likely to settle on us, pose for a photograph, bask on a flower. Once they are on the wing, it’s all business.

“If they’re males, they’re looking for females,” Donahue says. “If they’re females, they’re looking for food plants where they can lay their eggs.”

Butterflies are promiscuous, but also strict practitioners of family planning. The females will mate repeatedly, then store the sperm separately from the eggs. They only fertilize the eggs once they’ve found a spot suitable for their young.

Finding the right plant can amount to an exhaustive shopping trip. Most butterflies will lay eggs on only one or two types of plants. Anise swallowtails like fennel; California sisters, coastal live oaks; marine blues, ‘Cape Plumbago’ and locoweed; red admirals, nettles; monarchs milkweed; and Gulf fritillaries, passion vines.

How do these little bugs find the exact plants that they need in our big crazy urban grid? “They’re really good botanists,” says Donahue. “They can detect a food plant by infrared radiation of the plant or by the smell. Every plant has a chemical signal.”

When butterflies become extinct, it’s usually because their all-important caterpillar plants have fallen in the path of development. Reports of one extinction, happily, were greatly exaggerated. The Palos Verdes blue, whose eggs can only develop on a rare breed of locoweed on the Palos Verdes Peninsula, was recently rediscovered on military land. Euphoria was such that Chris Nagano, a biologist with the U.S. Fish and Wildlife Service and a colleague of Donahue’s, even saw a two-star general out helping to restore the dune.

What we take to be the same butterflies throughout the summer are probably several generations. Most adults live four to eight weeks. The butterfly you see in your garden is probably the insect equivalent of Lassie, replaced several times before the series ends. The exception comes for the handful of Western butterflies that migrate, such as monarchs. The generation born when the population is programmed to migrate to the Sierra in February and back to coastal over-wintering sites in October can live six or seven months.

No rule is perfect. Sometimes normally short-lived butterflies suddenly qualify for gold watches. A change of season and genetic flukes can trigger a long dormancy. These dormant specimens might live many months, even years as eggs, and months as caterpillars and even as adult butterflies. Something will have directed their metabolisms to slow to near standstills.

Fourth-grade science teacher Brandon Scully, whose class at Second Street Elementary in Boyle Heights rears caterpillars in the school garden, has reported: “Some of the adults come right out. Others go a whole season, and they don’t come out until the next year. All of a sudden on a bright day in January, boop, one will come out.”

On hearing this, Donahue grins delightedly. This is nature at its most resourceful, he says. Time-release mechanisms in eggs allow a successive release of the species throughout the year.

“Some at least will succeed,” he says. “That’s how they survive drought and forest fires.” Some desert varieties lay dormant until a rain, when the food plant for the caterpillars will leaf out. “It really is an exquisite web of interrelatedness.”

In home gardens, the interrelatedness is no less exquisite. Females find the right caterpillar plants, whether it’s radishes or parsley. As the leafy spring greens die off and nectar flowers bloom, the larvae rapidly evolve and the butterflies appear. The trick, says Donahue, is to plant enough native plants to support the caterpillars.

He’s not surprised at the story of Trish and Chris Meyer, who run a computer graphics business and butterfly garden out of their Sherman Oaks home. In six years, they’ve become so besotted with native flora and fauna that they ripped out all the ivy put in by developers and replanted with beds of gum plant, deerweed, milkweed, verbena and Mexican sunflowers.

Their strategy, according to Chris, was to tempt passing butterflies into the garden with nectar and put the host plants for caterpillars nearby. The eggs and caterpillars then attracted so many bird and wasp predators that Trish began whisking the caterpillars off to safety and rearing them in cages, until the adults were ready to be released.

When the Meyers found commercial milkweed plants killed their caterpillars because they had been treated with pesticides, they stopped buying them from nurseries. The Meyers built their own greenhouse and started propagating their own plants from seeds. Trish even began contributing to plant lists for the L.A. Chapter of the North American Butterfly Assn.

Butterflies do that to you, says Donahue. But if you don’t go whole hog, he advises, borderline sloth is the next best thing.

“One of the best friends of butterflies is a lazy gardener,” he says. Letting the fennel go to seed and passion vine run amok is creating a breeding ground for swallowtails and Gulf fritillaries. If you leave leaf mulch, don’t use insecticides and don’t canon-blast plants with hose water, the more likely you are to have butterflies.

As for good nectar plants, those are easy. Evolution made butterflies picky about caterpillar plants, but adults will drink nectar where they find it. Shape is the important factor. While hummingbirds can suspend themselves in air to drink from tubular flowers, butterflies need a flat, upward facing flower that they can hold on to. Native yarrow, ceanothus, thistles, daisies, zinnias and marigolds, and buddleia and milkweed are all excellent nectar plants. Unlike plant snobs, butterflies adore bougainvillea. The classic, buddleia or “butterfly bush,” has a light sweet fragrance, very like drugstore perfume. Lore has it that butterflies are partial to yellow.

Identifying butterflies takes some practice. Don’t feel bad if the Gulf fritillary in your garden is actually a painted lady and the monarch is actually a Gulf fritillary. Experts don’t necessarily see the dots and stripes either. They look for the gestalt of a butterfly. “It’s the way it moves and where you see it,” Donahue says. Habitat is equally telling. “From a distance, the California sister and Lorquin’s admiral look much the same. But if one’s in an oak, it’s a California sister. If it’s in a willow, it’s a Lorquin’s admiral.”

When you hear reports of butterfly populations, they’re normally based on butterflies spotted by their gestalt. Susan Immer leads the Monrovia butterfly census, one of a number conducted all over the country between late June and early July. Her counters have seen populations there bounce up and down, from 1,600 butterflies in four hours two years ago to only 118 last year. The crash was because of last year’s drought.

Butterflies live in boom-bust cycles, explains Donahue. This should be a good year for butterflies because we had adequate rain. Next year, expect a fall for butterflies and a boom for predators, such as birds and spiders.

Butterflies are so tasty to so many predators, including lizards, cats, birds and spiders, that they have evolved amazing defenses, from spines on caterpillars to a taste for the leaves of poisonous plants. While milkweed nectar isn’t poisonous, milkweed leaf is, at least to birds. It won’t kill them, but they will feel like they ate potato salad at a church social. The monarch caterpillar’s exclusive diet of milkweed leaves has made its flesh sickening to birds, and itsr orange and black coloration synonymous with a warning signal. The birds’ aversion is so hard-wired that similarly colored butterflies, such as Gulf fritillaries, enjoy vicarious immunity, even though they don’t eat milkweed as caterpillars.Donahue explains this to the children as if the monarch is speaking. “Look at me,” he says. “I’m brightly colored! I’m poisonous!”

As he releases the demonstration monarch and it flutters off, a child presents him with a wing of a Gulf fritillary found among the mulch. Taking a pen, Donahue flakes off one of the tiny scales that cover the wings.

“This,” he says, “is as close as you’ll ever get to pixie dust.”

Emily Green can be reached at emily.green@latimes.com.

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Who’s who in the winged set

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There are roughly 130 species of butterflies recorded in Los Angeles County. However, many are found only in specific microclimates, say, the foothills or the beaches. For example, the state butterfly, the yellow-winged California dogface, lives only in San Bernardino, where it feeds exclusively on false indigo. The El Segundo Blue is strictly found in the dunes under the flight path of Los Angeles International Airport. But a dozen or so species can be found across the L.A. Basin. Here’s how to identify them, along with some menu suggestions for sustaining their often-neglected caterpillars.

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Buckeye: Native across southern United States, but thought of as a tropical butterfly. Series of three large spots on a brown back with smart red details. Territorial and known to chase off intruders by furiously beating its wings. Caterpillar plants include snapdragons, monkey flower and lawn weed plantains.

Cabbage white: European. White with black dots. Most common garden butterfly. Caterpillars feed on members of the mustard family, including broccoli, cabbage and lettuce.

Fiery skipper: West Indies, southern U.S. Orange-brown, small, punky butterfly often mistaken for a moth. Caterpillars feed on Bermuda grass and crab grass. Does well in L.A.

Gulf fritillary: Mexico, southern U.S. Orange back and dramatic brown underwing with orange streaking and silvery white spots, like a good Marimekko print. Caterpillars need five-leafed passion vines. Adults drink lantana nectar.

Lorquin’s admiral: Native. Brown with orange wing tips and white bands, like a chieftain’s head-dress. Found around streams. Caterpillar plants include wild cherry, willows, poplar and fruit trees. Nectar plants include privet hedges.

Monarch: Native. Same as the eastern monarch, except they commute from the California coast every February to California’s Sierra Nevada and Nevada’s Great Basin, then back to the coast in October, instead of from Mexico to Canada. Orange with black window-pane edging. Relatively uncommon in Los Angeles, but butterfly gardeners record steady visitors to ornamental South American milkweed (Asclepias curassavica) and what little native milkweed is left in the Santa Monica Mountains and along Stocker Street in Baldwin Hills.

Mourning cloak: Native. Large brown butterfly with luscious yellow fringe and blue dotting. Caterpillar plants include willow, elm, hackberry and oaks. Butterflies become many months old and are so territorial that lepidopterist Charles Hogue recorded them diving at pigeons. Winter dormancy so light they emerge for sips of nectar now and then.

Painted lady: Native. Orange splotches on black with white spots near the tip of the wings. Weak migrations north most years. If you see one flying high and strong and north, it’s going to Kern County or beyond. Explosive, huge migrations north in El Nino years. Wide range of host plants, including thistles for caterpillars, daisies for adults.

Marine blue: Native. Small, light blue back, gray zebra-patterned underwings. Caterpillars like sweet pea, wisteria and ‘Cape Plumbago.’

Swallowtail, anise: Native. Large, black and yellow striped, butterfly, most common in the city and on the coast. Caterpillars feed on citrus, parsley, dill, carrots and fennel.

Swallowtail, Western Tiger: Native. Less common than conspicuous where they occur. Magnificent black and yellow stripes; males like to patrol treetops and hilltops. Caterpillars like Western sycamore, cottonwood, willows, wild cherry and ash.

West Coast lady: Native. Orange and black. Almost identical to painted ladies, but for an orange bar near the tip of the wing. Migrates north periodically. Caterpillars on mallows; adults on wide range of nectar plants.

-- Emily Green

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How to learn more

Web sites: The L.A. chapter of the North American Butterfly Assn. offers gardening tips, nursery contacts and contacts to participate in the national butterfly census every July; at www.naba.org/chapters/nabala. The Xerces Society offers history, links and Sierra Club contacts at www.xerces.org. The U.S. Geological Survey keeps records butterflies spotted in the L.A. basin; at www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/chklist/states/counti es/ca37.htm.

Booklet: “Butterfly Gardening in Southern California” by Julian Donahue (Natural History Museum of Los Angeles County, $4), sold at museums, nurseries and L.A. Audubon Society bookstore, 7377 Santa Monica Blvd., West Hollywood, (888) 522-7428.

Book: “Insects of the Los Angeles Basin” by Charles Hogue (Natural History Museum of Los Angeles County, $45).

Butterfly House: Pavilion of Wings, Natural History Museum, 900 Exposition Blvd., L.A.; (213) 763-3466. 10 a.m. to 5 p.m. daily through Labor Day. Adults, $3; children, $1; students, seniors, $2.