More than three million species of insects exist in the world and people hate just about all of them. We therefore take note when one particular insect, the monarch butterfly, earns universal love and widespread concern. Monarch populations are noticeably declining, so we have to ask: If things keep going the way they are, could monarchs go extinct?

Insects multiply so fast and in such large numbers that it's hard to imagine any could totally disappear from the Earth. But it's happened before. According to Endangered Species International, 59 insect species have vanished in modern times -- including the lovely Xerces blue butterfly after San Francisco developers destroyed its coastal sand dune habitat.

Fortunately, the monarch lives over a much larger area than the Xerces. It stretches from Canada to Mexico. But like the Xerces, it suffers from the potentially fatal flaw of overspecialization. It eats only one kind of plant. And much of the total population -- an estimated one billion monarchs -- spend the entire winter in a very small area of the Sierra Madre Mountains in central Mexico.

Be afraid. Be very afraid.

Although adult monarchs drink nectar from many kinds of flowers, their caterpillars eat only the foliage of milkweeds, such as common milkweed (Asclepias syriaca), butterfly weed (Asclepias tuberosa), and swamp milkweed (Asclepias incarnata). There used to be plenty of milkweeds around -- you don't get called a "weed" for nothing. However, much milkweed habitat -- fields, grasslands, roadsides -- is lost to development each year. In the Midwest, large swaths of marginal cropland that formerly supported milkweeds have been plowed under and planted with corn to make ethanol -- a short-sighted gift from Congress to the deep-pocket lobbies of Big Ag.

emCommon milkweed in the wild. Photo:

Or should I say, Big Gag. Fewer milkweeds = fewer monarchs. But we have ethanol!

The Really Big Threat However, a more existential threat to monarchs is their amazing mass migration from Canada and the U.S. to the trees of a 200 square-mile area in Mexico called the Monarch Butterfly Biosphere Reserve. Here the monarchs wait out the cold winter up north by roosting in the trees in such mind-boggling multitudes that branches sometimes break and fall under their weight. When instinct tells them it's time to leave, they mate and start the thousand-mile journey home, laying eggs on milkweeds along the way.

But what if something terrible happens while they're still so concentrated in the Reserve? Logging takes place in parts of it. In 2002, a freak winter storm killed 70% of the overwintering butterflies, leaving piles of dead monarchs two feet deep on the forest floor. What if the next storm is more severe? What if some delusional maniac with a helicopter and tank of DDT decides to sterilize the Reserve to get his 15 minutes of fame? Harvey Updyke Jr. pulled the same kind of stunt when he poisoned Toomer's Oaks at Auburn University.

Be afraid. Be very afraid.

What Can Be Done? Thanks to their migratory imperatives, monarchs will always be at risk no matter what we do. We can't stop a storm. However, we can do things close to home to mitigate the risk and make us feel better. We can stop turning farms into shopping malls. We can stop converting marginal cropland into ethanol factories.

Many monarch advocates urge everyone to plant common milkweed in their gardens to replace what's lost in the wild. This is problematical. For one thing, Joe Sixpack hasn't heard of common milkweed, wouldn't know common milkweed if it kicked him in the chiclets, and no garden center in town sells it. And let's be honest -- it's an invasive weed that spreads quickly by seeds and rhizomes. That's fine for people who live on farms or have an acre or two to devote to native plants. But in the burbs? No way. It's just not the next 'Endless Summer.'

What now? How about planting a nice milkweed with spectacular flowers that Joe Sixpack will love? Butterfly weed.

emButterfly weed. Photo: Ladybird Johnson Wildflower Center/em

Butterfly weed is native, perennial, well-behaved, tough-as-nails, and easy to grow. It forms a clump about three feet tall and crowns itself in early summer with blossoms that are usually bright orange, but may be red or yellow. All it needs is sun and well-drained soil. Due to long tap roots, it's difficult to dig from the wild. However, it's easy to grow from seed and you can get plants at many garden centers and mail-order nurseries. Adult butterflies (many kinds, not just monarchs) love its nectar. Monarch caterpillars munch on its foliage. Here's what a happy monarch caterpillar looks like.

emMonarch butterfly caterpillar. Photo:

Of course, if you really want your garden to be one of millions of tiny refuges that keep monarchs going, you'll have to back off pesticides. You don't want to be a less-famous version of the maniac in the helicopter.