The wonders called butterflies

By Danny Staehr

It’s time for yet another Bugs and Butterflies class at the Lincoln Children’s Zoo. For today’s group of 5–8 year olds, this includes a visit to Laura’s Butterfly Pavilion. The pavilion is open from 10 a.m. till 5 p.m. each day. It is a seasonal exhibit that is in operation from June through mid-September. This is where I get the opportunity to bring together my little friends: the caterpillars, the butterflies and the kids.

At the zoo we encourage children young and old to “learn firsthand,” and what better way to learn about butterflies than by getting to hold one on your finger! During the summer, the butterfly exhibit is home to hundreds of butterflies and caterpillars, with names like monarch, zebra swallowtail, painted lady, buckeye, Julia, queen and others. A variety of plants attract the butterflies or serve as food for the caterpillars. Some of these plants you’ll commonly find in your herb garden: fennel, dill, parsley. Others may be considered weeds: milkweed, nettle, plantain. Then there are the flowering plants: zinnia, asters, lantana, petunias, passion vine.

My visiting class settles down, seated on the brick retaining wall. I introduce myself and open with my first question of the day for the youngsters to answer: “Has any one here heard the M-word we use when talking about the butterfly life cycle?” Hands shoot up, eager students shout out … METAMORPHOSIS!!! I jump back with shock and awe. “Correct! My, what a smart group I have here.” And so we launch off into the life cycle of the butterfly, and soon the children start asking ME questions: How long does a butterfly live? Do butterflies sting? What do butterflies eat? Can butterflies hear?

The miracle we know as metamorphosis is the four-stage process the butterfly goes through as it changes from egg to larva to pupa to winged adult.

A butterfly species that is familiar to most of us is the orange and black monarch (Danaus plexippus). In this species, the gravid female lays her eggs one by one on milkweed plants, depositing them on the underside of the leaves to offer greater protection from the elements. The female may lay 300 or more eggs, about the size of a pinhead, during her short life span. Depending on temperature and humidity, the eggs hatch in five to seven days.

A tiny larva or caterpillar emerges from the egg, eats its shell and then commences to eat and grow. These little eating machines pass through five stages, or instars, each one larger than the last. The larva sheds its skin each time it passes to the next instar. About seven to 10 days after it hatches out of the egg, it’s ready to move on to the next stage, the pupa.

The pupa is also called the chrysalis. Inside this chrysalis the fat caterpillar that has been eating and eating transforms itself into a beautiful butterfly. For about 10 days, this little time capsule is home for the caterpillar, until a hormonal signal tells the developing butterfly to split open the pupa shell. The adult crawls out and wiggles free from the chrysalis and begins to pump fluid from its body out through veins in its wings. Once the wings are expanded and dried, the butterfly is ready for flight. It is an adult and has reached the end of its growth. All that is left now is to find a mate; pair; lay eggs, if female, or pair with other females, if male. In about two weeks, the butterfly will die.

But for some of the monarch butterflies, depending on when they emerge from their chrysalis, they take off on a remarkable migration and head south to Central Mexico to overwinter and mate. In the spring, they’ll begin the return journey north.

This trip, however, is not like the migration of many birds. The same monarchs that fly south to Mexico at summer’s end never return back to Nebraska. The overwintering generation lays its eggs either in Mexico or Texas, a new generation emerges from those eggs, flies farther north and lays more eggs, so that the butterflies that return here in the summer may be three, perhaps four generations removed from those that migrated to Mexico.

During the past century, much of the wild habitat along this migration route has been destroyed, making this long journey more difficult for the monarchs. To give them a hand, and to attract some of these monarchs and other butterflies to your yard, you can plant a butterfly garden with flowering plants that produce nectar for the adult butterflies to feed on, as well as host or food plants for the caterpillars.

Each butterfly species has a particular type of host plant it lays its eggs on. In the case of the monarch, it’s milkweeds. Black swallowtails (Papilio polyxenes) are attracted to parsley, dill, fennel or carrot tops. Snapdragons and plantain serve as food for the common buckeye (Junonia coenia). Most fritillaries (genus Speyeria) will lay eggs on violets, while viceroys (Limenitis archippus), mourning cloaks (Nymphalis antiopa) and red-spotted purples (Limenitis arthemis) prefer willow. Hollyhocks attract painted ladies (Vanessa cardui), while false nettles attract red admirals (Vanessa atalanta).

Plant your host plants in groups, in a protected area with plenty of sun. Elsewhere in your garden sprinkle in seeds of annuals like zinnias, phlox, coreopsis and cornflowers. Perennials with large flowers, like purple coneflower, blackeyed susan, yarrow and buddleia, make excellent butterfly attractors.

You may also want to have a water feature, a place where some species of butterflies will “puddle” around the wet sand. Remember not to use pesticides, as they may kill the larvae and butterflies. And don’t worry, most garden butterfly species lay only one or two eggs on each host plant before moving on to the next plant. As a result, the caterpillars have plenty of food for all.

If you are fortunate enough to find chrysalids on your host plants, you may want to leave the plants standing through the winter, as some species overwinter in that form. Other species leave the area and head to the southern U.S. for the winter, only to return next summer when their favorite plants are back. The mourning cloak overwinters as an adult and can sometimes be seen flying about on warm winter days.

Even if you don’t have a place of your own to plant butterfly attractors, you may want to head to a public garden or state park and take along a butterfly guide, such as “Butterflies of North” America by Jim P. Brock and Kenn Kaufman. A couple of great Web resources I use to aid in butterfly identification and information are Butterflies and Moths of North America, http://www.butterfliesandmoths.org, and Monarch Watch, http://www.monarchwatch.org.

An excellent guide to butterfly gardening in Nebraska can be found at your local County Extension office or online at http://www.ianrpubs.unl.edu/sendIt/g1183.pdf.

This article is provided by a member of Wachiska Audubon Society and features writing related to nature, the seasons and relevant environmental issues. For more information, visit http://www.wachiskaaudubon.org.

More information on the zoo can be found at http://www.lincolnchildrenszoo.org.

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