The Beautiful Moth

ONE pleasant evening a moth flew into a plush restaurant. As it fluttered by her table, a lady dining there frantically shooed the moth away as if she were being attacked by a disease-laden mosquito! The moth proceeded to another table, finally alighting on a man’s lapel. This man and his wife had an entirely different reaction—they admired the moth, reflecting on the beauty and harmlessness of this delicate creature.

“Moths are about as harmless as a creature can get,” explains John Himmelman, cofounder of the Connecticut Butterfly Association. “They have no biting mouth parts, and some adults, such as the well-known luna moth, don’t eat at all. They don’t carry rabies or any other diseases, they don’t sting . . . In fact, most people don’t realize that butterflies are actually day-flying moths.”

Everyone admires butterflies, but few stop to admire the beauty and variety of moths. ‘Beauty?’ you may say, skeptically. Some think of the moth as merely a lackluster cousin of the beautiful butterfly, yet both are given the same scientific classification—Lepidoptera, meaning “scaly wings.” The wide variety observable among these lovely creatures is astounding. The Encyclopedia of Insects states that there are 150,000 to 200,000 known species of Lepidoptera. But of these, only 10 percent are butterflies—the rest are moths!

Like many other people, I hardly thought of moths except when putting away my winter clothes and placing mothballs around them in an attempt to repel the clothes moth. I did not know that as adults, moths do not eat fabric at all—they only do so while in the larval stage as caterpillars.a

What changed my outlook toward moths? Some time ago my husband and I paid a visit to some friends of ours named Bob and Ronda. Bob knew quite a bit about moths. He showed me a small box containing what I at first thought was a beautiful butterfly. He explained that it was a cecropia, or robin moth, one of the largest moths in North America. It can attain a wingspan of up to six inches [15 cm] and has a life cycle of one year. How amazed I was to learn that its life as an adult lasts a mere 7 to 14 days! A close examination of the lovely cecropia gave me a whole new perspective on moths.

Bob pointed to some small specks on the bottom of his box. “These specks are eggs,” Bob explained, “and I hope to raise them to adulthood.” Raise a moth? I was intrigued by the idea. It turned out, though, that executing this plan was not so easy. For two weeks Bob tried unsuccessfully to hatch the eggs. He then decided to mist them with water. Within a week after the misting, 26 of the 29 eggs hatched in one day. Bob then placed the fragile larvae, each about the size of a mosquito, into a smooth casserole dish to keep them from crawling out.

The first meal the emerging larvae ate was their own egg cases. After that, Bob had to provide food, which proved to be a bit of a challenge. After doing some research, he tried feeding them maple leaves. The larvae crawled onto the leaves but did not eat them. However, when Bob offered cherry and birch leaves, they readily consumed them.

When the tiny larvae had grown into caterpillars, Bob transferred them to a terrarium with a screened top. The terrarium provided the proper balance of moisture for the caterpillars and the leaves. It also served to contain the caterpillars, since they developed a wanderlust as soon as they were able to crawl.

Providing food for 26 hungry caterpillars turned out to be more work than expected. Each time that Bob packed the terrarium with leaves, the caterpillars devoured the entire supply within two days. At this point he enlisted the help of his sister and two young friends, a boy and a girl, to share in watching and feeding the growing brood.

The caterpillars’ consumption of large quantities of food is vital, not only for growth during their larva stage but also for nourishment when they become adults. You see, the adult cecropia moth does not have functional mouth parts, and it does not eat at all! For sustenance during its brief adult life, it depends entirely on the food it ingested during its larval stage.

Getting New Skins

As the caterpillars grew, they shed their skins, or molted, several times. The stages of a caterpillar’s life between molts are called instars.

A cecropia caterpillar’s skin does not grow, so when the caterpillar becomes so large that its skin is stretched to the limit, it is time for it to molt. Bob could tell when this was about to happen because the caterpillars stopped eating. After spinning silken pads and attaching themselves to them, the caterpillars remained still for several days while they developed a new skin. When the new skin was ready, the caterpillars simply walked out of their old skins, leaving them attached to the silk pad. Seeing the caterpillars in their last instar, I was amazed at how big they had grown. They were nearly five inches [12 cm] long and larger in diameter than my index finger.

Spinning a Cocoon

After the last instar, each caterpillar spun a cocoon—a large mass of grayish threads affixed to a stick. Cecropias make cocoons of two types. One is a large, loose, baggy structure with a rounded bottom and a tapered neck. The other type is smaller and denser and is oblong in design with a tapered neck and bottom. Both types contain a tightly-wound inner cocoon. Cecropia cocoons are generally reddish-brown, brown, drab green, or gray. Compared with the cocoons of other North American species, the cocoons of cecropia moths are enormous—up to four inches [10 cm] long and two inches [5-6 cm] wide. And these amazing structures are able to protect their inhabitants in temperatures as low as -30 degrees Fahrenheit [-34° Celsius].

After the caterpillars settled into their cocoons, there was nothing for us to do but wait patiently. The unveiling took place the following spring, about one year after Bob had first received the adult moth. Bob placed the sticks holding the cocoons in a piece of plastic foam to keep them standing upright. Soon, all the cecropias but one emerged from their cocoons, making the patience and hard work worthwhile.

Increased Appreciation for Moths

Witnessing the remarkable life cycle of the cecropia has caused me to pay more attention to moths fluttering around lights and resting on buildings. My experience also prompted me to find out more about these fascinating creatures. For example, I learned that moths and butterflies are impressive fliers, certain varieties migrating considerable distances. The tiny diamondback moth has a wingspan of only one inch, [2.5 cm] but it periodically flies between Europe and Britain via the turbulent North Sea. And sphinx moths, or hawkmoths, hover over flowers the way hummingbirds do.

Some time after witnessing the life cycle of the cecropia, I saw one resting on a bush under a light. I knew that because the scales on a moth’s wings are extremely delicate, you should never pick it up by its wings. However, if you place your outstretched hand in front of a moth, it may walk onto your finger. When I tried this, the lovely creature rewarded me by resting on my middle finger. Eventually, it took to flight over the treetops. As it flew away, I thought of how much it looked like a butterfly. The next time you think you see a butterfly, take a second look. It may very well be a beautiful, harmless moth.—Contributed.

[Footnote]

[Pictures on page 16, 17]

1. Robin moth (cecropia)

2. Polyphemus moth

3. Sunset moth

4. Atlas moth

[Credit Lines]

Natural Selection©-Bill Welch

A. Kerstitch

[Pictures on page 18]

Developmental stages of the cecropia moth include:

1. Eggs

2. Caterpillar

3. Adult moth

[Credit Line]

Natural Selection©-Bill Welch