Growing Butterflies

Nothing says summer like butterflies drifting lazily across a meadow. And just like fireflies use their flash to attract mates (see entry below), butterflies call to each other with their loud exuberant colors—the tiger swallowtail’s bright yellow, for example, calling other swallowtails.

They are flying billboards, advertising—what else?—sex.

While we all love butterflies, too few people realize you can actually GROW butterflies. Yes, grow them. If you plant the flowers their caterpillars crave and nectar-rich flowers the adults need, you can nurture larger numbers of butterflies.

Take milkweed, for example. Monarch butterflies—those big orange dudes—only lay eggs on milkweeds, as the caterpillars eat this, and nothing else. The caterpillar incorporates noxious milkweed poisons into its chemistry, transforming into adults that use their bright orange to advertise their distastefulness.

Milkweeds also produce stunning nectar-infused flowers that butterflies find irresistible. So put milkweed in your garden, and you’ll grow Monarch butterflies while offering nectar for dozens of varieties of butterflies and skippers, their smaller cousins.

Grow dill or fennel, and black swallowtails will lay eggs in your garden. Hollyhocks host painted ladies and gray hairstreaks. Violets support members of the fritillary clan, a diverse group of stunning fliers. The pipevine swallowtail’s caterpillar lives on, you guessed it, pipevine and Dutchman’s pipe; the spring azure—a dainty powder-blue beauty—craves Spirea and viburnums, and so it goes. For a long list of host plants, try here or here.

So far, however, it’s been a thin butterfly summer—I’ve only seen only two Monarchs so far, and precious few swallowtails. To understand butterfly populations, the North American Butterfly Association leads July 4th counts of butterflies nationwide. Join me on my count—I’d love to welcome you.

And grow butterflies. Plant dill and milkweed to start, and see where it goes. Enjoy.

Bright lights, no pity

Flash! I saw the first firefly of the young summer strutting his stuff tonight, lighting my way while walking the dog. And I do mean he: the fireflies you see flying and flashing are males, advertising their wares by sending signals into the night.

The larger females are flightless, sitting in grasses or on branches checking out the light show above them.

And each species of firefly has its own unique Morse code, using both time and space to alert others as to which species it might be. So one firefly performa a flashing J pattern, distinct from the one that performs, say, one low dash, or three high dots.

When the female spots an acceptably sexy flashing male of the proper species, she has the appropriate answer, a coded response. He flies to the signal, and mating ensues—and she soon lays eggs that themselves even glow in the dark!

But it gets even better: in one group of fireflies, the female has decoded the flashing pattern of males of different species. He flashes, looking for a mate; she responds. He flies down, visions of sugarplums dancing in his head… And she devours him.

Sex and food explain just about everything in nature, even the welcome flash of fireflies.

The Return of the King

Some people mark the calendar by days of the week, or dates of the year. Me, I’m a naturalist, and mark the calendar by the rhythms of the natural world. Skunk cabbage in bloom in a February wetland signals the coming spring; the first trillium or trout lily announces high spring; the first warbler migrating through deserves a celebration.

Last week, June 5—the day my nonprofit was hosting its huge annual gala—a Monarch butterfly drifted lazily across my path.

The first Monarch of 2008. Good omen for the gala. And, for me, the official beginning of summer.

Monarchs—those big butterflies wearing Flyers jerseys—famously spend the winter in remote Mexican mountain valleys, where they encase the trees keeping each other warm. There, they become the longest-lived butterflies of all, surviving as long as nine months waiting out the winter season.

As spring dawns, the females begin the journey north, making it maybe to Texas, searching for the first milkweed, the only plant they lay their eggs upon. After the females lay their eggs, they collapse from exhaustion—and die.

And it’s that next generation that continues migrating north—and here it is, in early June. Summer is here; nature’s clock continues, and the Monarchs are back in town.

Want to know more? Visit Monarch Watch or Journey North.

Out of the Frying Pan...

A soaring wall of thunderheads just passed overhead, rumbling and flashing but not raining one-tenth as much as I expected.

Nonetheless, it broke the back of that psyche-shattering heat wave we’ve been mired in. Check this out: my kids have been given half-days off to avoid the heat. Early June and it feels like the dog days of August.

So the last two days here, parents have been lining up at school carpool queues to pick up their little charges, not wanting them to swelter on the long bus trip. And the cars—all those Suburbans and Tahoes—sit there, engines idling, air conditioners on full, waiting to whisk kids home to central air turned all the way up.

It’s ironic: as the heat climbs, power usage escalates—or in your Cadillac, it Escalades. As usage climbs, we burn more fossil fuels cooling down, and greenhouse gas emissions rise, forming a positive feedback loop. The hotter it gets, the more power we consume; the more power we consume, the hotter it gets. And carbon dioxide concentrations keep ratcheting up.

Two weeks from now, I expect we’ll hear this is one of the hottest Junes ever. Meanwhile, just last week, Congress punted on a climate change bill that, imperfectly unexplainable as it might have been, would at least have been a statement. Those who filibustered claim combating climate change is too “costly.”

Maybe, but tell that to a farmer with scorched corn.

Thankfully, both McCain and Obama take climate change seriously, so we’ll see what happens next year. (Meanwhile, Chevy is abandoning Tahoes and Suburbans for the emission-free electric Volt. Now there’s progress.)

But at some point, like with the war effort, we’re going to begin to need to make some personal sacrifices to cool the climate. We continue wanting to have our cake and eat it too, but the oven doesn’t work anymore.

Still, the heat wave broke. Tomorrow’s high will only be 89. Whew.