Monday, March 31, 2014

Wings in the Garden

In the 1980’s when butterfly gardening was all the rage, I just had to have one of my own, starting with a small fenced area planted with all sorts of “butterfly” plants to attract them to this little spot where I could, in my fantasies, sit on a garden bench among the fragrant herbs and watch clouds of nectar-sipping beauties flitting about. Ha. Didn’t take me long to come to my senses and realize that you can’t corral butterflies like horses; what was I thinking? I needed to find out more about those winged gypsies of the insect world. A couple of reference books soon grew to a library of a dozen or more, and I began to think I might be an expert on butterflies and moths. But then reality set in and I realized that though my books had a lot to say about the adults, there wasn’t much about caterpillars. We can’t have butterflies if we don’t take care of their babies, but it seemed very little was known about all the life stages of Lepidoptera, from egg to larval stage, various instars, food plants, how and when they hibernated, hatched, and often, even what metamorphs into what? Then, in 2005, a book was published by Princeton University Press; “Caterpillars of Eastern North America” by David L. Wagner, and I started to really learn about the diversity of those insects, their lifestyles and plants they need to live. An estimated 8,000 moth and 700 butterfly species are found in North America alone, with nearly 200,00 worldwide. That is a lot of caterpillars. More are identified each year, and as comprehensive as this book is, even I find an occasional one that is not listed in it. I can only compare with different families and try to guess where in which one they belong. I find them totally fascinating; the diversity of caterpillars and their phenomenal survival tactics is mind-boggling.
The buzz these days is about saving the beautiful, beloved, familiar black and orange monarchs, but there are many more endangered butterflies that need our concern. Tiger swallowtails are the first butterflies we see here in early spring. The chrysalises overwinter in leaf litter (one good reason to not keep a too-tidy garden in the fall) and hatch out with the warming spring sun, just in time for lunaria (aka money plant) to bloom in the awakening garden, providing them with much-needed nectar when there are not many other flowers.  

Luna moth, just hatched. Its tails are not yet completely dry and extended.

The number of plants needed to sustain a butterfly and moth population is astounding. We all know that monarchs need the asclepias family, including milkweed, but many other butterflies also have specific requirements for life. Great spangled fritillaries visit milkweed for nectar too, but the caterpillars, which overwinter and become active in spring, must have violet leaves to eat; if there are none available, they will starve and die. (Not a problem here with native violets everywhere.) Beautiful luna moth caterpillars subsist on tulip tree (lirodendron) leaves. The carrot family is host for giant swallowtail caterpillars. We’ve learned to live with holes in leaves; helping sustain pollinators and beautiful insects is one of the best parts of being a gardener.

Pipevine swallowtail caterpillars

Planting a few nectar-rich flowers for butterflies and other pollinators is not nearly enough to make a good butterfly garden. There also has to be a wide range of plants for caterpillars to eat: no caterpillars, no butterflies. Here at Chaos we grow fennel, dill and parsley for swallowtails, to suppliment Queen Anne's lace and wild parsnip growing wild Out Beyond. 
 Some years ago when I planted native Dutchman’s pipevine, hoping to attract pipevine swallowtails, I didn’t realize how invasive that plant is—but, now, when it literally swarms with swallowtail caterpillars each year, I can’t get rid of it. I just deal with underground runners that pop up everywhere.  
Spicebush swallowtail caterpillar
Bad-tasting plants like these are swallowtails’ defenses, making them unpalatable to birds. Snake-mimic spicebush cats that munch spicebush and sassafrass leaves, start out looking like bird droppings, and with several instar changes, become orange and finally green with "snake eyes"; rolling themselves up in leaves so only the snake markings show to predators.  Some caterpillars rely on camouflage. I accidently put my hand on an oak moth caterpillar last summer; and even knowing it was there, its coloration was so close to the tree bark that it took several minutes to see it. Many caterpillars have stinging hairs, some squirt chemicals, and a few actually squeal and bite at predators. 
Oak moth caterpillar, camouflaged against the bark of an oak tree.
Here, most spring clean up is limited to paths and patios, leaving the majority of fallen leaves on beds, so overwintering caterpillars aren’t harmed. Luna moth cocoons are in leaf litter under the trees, hatching out in April, so I must wait to tidy up beds in the woods, or not. By that time most plants are big enough to hide the leaves anyway. Other pollinators live under there as well; plus carnivorous beetles, their larvae, and spiders that feed on harmful insects, making me careful about cultivating around plants so I don’t kill, for example, slug-eating firefly larvae.

I know; all caterpillars are not welcome in a garden. A single giant hornworm can nearly consume a tomato plant in one night, causing gardeners to curse loudly and crush it immediately. But not all hornworms eat tomatoes. There are some 70 species, many of which are plant specific, so randomly killing any you see would deprive us of many hawk and hummingbird moths that are so entertaining in the evenings. Introduced species like gypsy moths, bagworms, tent caterpillars, cabbage butterflies and cutworms wreak havoc in gardens, needing to be dealt with if we are to have vegetables to eat. We don’t use insecticides, instead relying on timing, floating row covers, plant collars, and natural predators. One alternative is bacillus thuringiensis, or BT, a natural biological control that is effectively used on larva of many kinds in certain situations. But it does destroy caterpillars, so apply with caution and only if necessary. BT can be found at any garden center. A must read for further information:  

For nectar, butterflies need cluster type flowers with flat surfaces for landing pads, such as sedums, milkweeds, salvias, verbenas, zinnias, clover, lilacs, et al. They also like a good mud puddle for salt that is necessary in mating, especially if it has rotten bananas, molasses, or sponges soaked in fruit juices and stale beer in it. A wide saucer or birdbath makes a good feeder. They are also attracted to carrion, dung piles, and sweaty people. If you are blessed by butterflies landing on you, they are probably licking up your salt.  

A little Melissa butterfly, tasting my finger
Moths prefer tubular flowers, especially night-scented ones like lilies, hostas, nicotiana, daturas, phlox, and have even been known to visit hummingbird feeders.  
Cecropia moth, one of our largesty silkmoths, seems to be declining because of parasitism by a tachinid fly that was introduced to control the gypsy moth, an invasive species from Europe that is devastating North American forests. Another example of many well-intentioned attempts to correct a problem has gone awry. Now, how far must we go to control the tachinid fly? And then, what?
All of these plants also attract many other pollinators, providing food for a wide range of insects which are not only vitally necessary to keep our plant world humming along, they are also important members of the food chain for both birds and mammals. Many are the staple foods in the diets of forest-nesting birds.

Besides my caterpillar book, my other favorite reference is a small, information-packed Pocket Nature Guide published by Johnson Books; “Painted Ladies of North America”.

With dwindling habitat worldwide and assaults on these insects with ever-growing use of chemicals, and intoduced predators, even the tiniest pollinator garden helps. I’m planting lots more agastache, salvias, herbs and lavender this year.

"May the wings of the butterfly kiss the sun
And find your shoulder to light on,
To bring you luck, happiness and riches
Today, tomorrow and beyond."
~Irish Blessing

Joplin Globe column March 29, Speaking of Gardens by Sandy Parrill with extra pictures and text


1 comment:

  1. Such an extended and well thought out post. It's amazing the extent to which we are blessed by our Creator when even one insect can be so inspiring.