Respect the Caterpillar! by Humane Gardener

October 11, 2014 by Nancy Lawson http://www.humanegardener.com/?p=377

 

We’re taught from an early age to think of blemishes and natural signs of growing older as flaws in need of removal or destruction. A still tasty but slightly bruised apple rarely makes it to market, and when it does, few shoppers buy it. A birthmark that could have been a thing of beauty is surgically removed. Wrinkles that were years in the making are lasered and collagened away.
It’s the same way with plants. At the first sign of “damage,” we’re expected to impose our will over the natural order of things. A leaf with holes or raggedy edges is a  weakness, and, according to the Landscaping Industrial Complex,  will surely lead to our entire garden’s undoing if we let it.
Caterpillars are especially victimized by this warped pursuit of false perfection. Often labeled “pests” and “menaces,” these essential denizens of healthy backyard ecosystems are treated like foreign invaders in their own land. They’re sprayed, picked off, hosed down and otherwise attacked for the crime of daring to feed themselves. A popular product, BT, is organic but nonetheless lethal; marketed as safe and natural, this bacteria-based treatment is anything but for caterpillars, whose guts rupture after eating it.
Just as often as we malign these animals, though, we simply don’t think about them at all. And that’s a problem, too. Most insects, including many caterpillars, are specialists, meaning they need certain native plants to survive. But many of the plants traditionally used in butterfly gardens are nonnative and do nothing at all for butterfly babies. As I explained in a recent column in All Animals magazine, the confusion runs deep and isn’t helped by poor nomenclature; gardeners across the country still revere the butterfly bush, despite its inability to support caterpillars. To make matters worse, the species, originally from Asia, is now a known invasive, taking over wildlife habitat in the U.S. and even, ironically, contributing to a demise of butterfly populations in England.
The steep decline of monarch butterflies in recent years has jolted the public into action and put a spotlight on the necessity of milkweed for species survival. But I’ve begun to wonder whether enough attention is being given to the impacts of our war with nature on all the other butterfly and moth species struggling to survive in ever-shrinking habitats. Just last year, three species of skipper butterflies in Florida were declared likely extinct, and many more around the country are in peril.
How profound will continued losses be? As entomologist and professor Doug Tallamy has pointed out in his book Bringing Nature Home, 96 percent of North American terrestrial bird species depend on insects to feed their young. To put in perspective the number of insects that requires, Tallamy notes that it takes an average of 9,100 caterpillars to raise one brood.
It’s abundantly clear that nature needs our help now more than ever—and that’s true not just for iconic species but for all the living creatures on our planet. Here are five ways to support habitat for caterpillars—and, by extension, many other animals in your backyard:
1. Host the Host Plants: Plants in every layer of the garden support caterpillars, from tiny native violets to towering oak trees. Online resources, including these helpful lists for Eastern-region gardens and Southeastern gardens, can help you get started.

Monarchs are now the most well-known insect specialists, inspiring a movement to plant more milkweed. Gardeners should plant several milkweed species that mature at different times, ensuring food for monarch caterpillars throughout the season. This butterflyweed, an orange-flowered native, has reseeded in several places on my property.

We tend to think of butterfly gardens as overflowing with flowers. But our native trees, bushes and vines are critical to the survival of many butterfly and moth species. Sassafras trees (the dark leaves shown here) feed Eastern tiger swallowtail and spicebush caterpillars. Virginia creeper vine is host to the Pandora sphinx moth caterpillar.

Just across from the sassafras grove that serves as one of my butterfly nurseries are nectar plants to feed this spicebush swallowtail and other wild denizens of the garden.

2. Leaf Well Enough Alone: When we treat our outdoor spaces like living room carpets—leaf-blowing and mowing and fertilizing—we are issuing a death sentence to so many creatures who live among the leafy, grassy layers. By letting organic matter decay under trees and in your garden’s in-between spaces, you can provide shelter for overwintering chrysalises as well as eggs, caterpillars and pupae of many butterflies.

While placing pots atop a retaining wall this spring, I spotted this little mourning cloak butterfly in the making wandering through the detritus of last year’s garden. This caterpillar feeds most often on willows but also eats American elm, paper birch, poplars, aspens, cottonwoods and hackberry. The adult butterflies are long-lived, overwintering in loose bark and tree cavities. Unfortunately, as with so many species, humans sometimes label them “pests” and spray trees to kill the larvae.

Trimming back some of the tall dead grasses in late spring, I found this spicebush swallowtail chrysalis that had overwintered deep in the mound. Needless to say, I put him back and stopped trimming. Even gardens that look dormant to our eyes are always filled with life.

3. Share the Wealth: If you enjoy growing vegetables and herbs as I sometimes do, your local lepidoptera will likely enjoy it, too. Don’t be surprised to find a black swallowtail caterpillar on your dill or a hornworm on your tomatoes. Though many people react in horror to the presence of hornworms, they are welcome in a balanced garden, where parasitic wasps often control the population by laying their eggs in the worms. And those hornworms who manage to escape that fate grow into stunning moths that help pollinate the garden.

Having a humane backyard often means sharing your bounty with creatures like this Eastern black swallowtail, who was cruising this summer over an onion plant on his way to the dill, just one of his preferred species.

Gathering mint one day for a watermelon salad, I didn’t notice I’d also gathered up a hornworm. I put him back in the garden so we could both enjoy the fruits of nature’s labor. Some hornworms turn into beautiful hummingbird moths, so named because they look and fly like tiny hummingbirds.

4. Learn Your Species: Like any proper host, you can help your guests have a pleasant stay if you learn just a little bit about their needs. That starts with understanding who they are and what they look like at all stages of their short lives. Of the many sites I’ve turned to, the Butterflies and Moths of North America is one of the most comprehensive.

Even a humane backyard in a pot can sustain caterpillars and other wildlife. At least six American lady caterpillars were munching on this licorice plant on my deck, so I potted up several more host plants and placed them nearby.

The resulting adults, American lady butterflies, were only too happy to dine on the nectar of the butterfly gods: orange zinnias.

5. Give a Little Respect: Take care to avoid all chemicals, including organic ones that may be healthier for you but deadly to our garden friends. Always be on the lookout for what lies beneath (a monarch caterpillar meandering over to a tree to form a chrysalis) or who’s hiding above (a swallowtail caterpillar curling up in a sassafras leaf). Spread the word about these animals, who are not “creepy,” as a recent well-meaning but poorly worded Washington Post story labeled them, but beautiful in their own right, quietly making their way through the world without much notice. But notice we must. And even more than that, we must take action—before they have nowhere left to go and all the butterflies, and their babies, are gone.

A red-spotted purple dines on rain-soaked cracks in the driveway. Its caterpillars eat cherries, poplars, oaks, hawthorns and other trees and bushes.

Also undemanding and unassuming, the Eastern-tailed blue flies low and likes flowers close to the ground, thus going largely unnoticed by people. The caterpillars eat buds, flowers and seeds. They have a fascinating symbiotic relationship with ants, who protect the larvae in exchange for the pleasure of eating a honeydew substance emitted by the caterpillars.