The Homeowners Column

The Homeowners Column

Moths Add Mystery to the Night

Photo of Sandra Mason

Sandra Mason
Extension Educator, Horticulture
slmason@illinois.edu

Ladies of the night get no respect. Ever heard of moth gardening? Butterflies attract all the attention. Granted many moths dress a bit drab compared to the garish garb of butterflies. There are, however, a group of moths called silkmoths that are flashy and flamboyant.

Silkmoths are known for their substantial wingspan and "furry" bodies. The moths are large and beautiful with equally large and beautiful caterpillars. Ok, maybe not beautiful caterpillars, but at least interesting. Luna, cecropia, imperial, regal, Io, polyphemus and rosy maple are just some of the Illinois silkmoths. Luna, also called moon moth, is a soft green color with a wingspan of 3 ¾ -5 ¼ inches. Luna shows off best when her long wing "tails" swirl and twirl as she floats on summer breezes.

One of our many activities here at the Extension office is identifying insects. Sometimes the client question is "Gee whiz what is it?" or "what's this thing eating my tree?". Recently a woman came in with a large green caterpillar. Imagine an apple-green hot dog with colorful cellophane swirled toothpicks strategically stuck in two rows across the top. Definitely a cecropia moth caterpillar.

A wide variety of plants are eaten by cecropia caterpillars: apple, birch, boxelder, dogwood, silver maple, peony, rose and willow. They are, however, seldom considered a pest because of their low populations on one plant.

This nice lady rescued the caterpillar as he was wandering in a parking lot where he was sure to meet Mr. Goodyear or Mr. Michelin. Since he was very large and in wandering mode, I figured he was looking for a place to spin his cocoon. (He had a certain swagger when he strutted so I knew he was a male.) I took him home and he formed his cocoon within 24 hours. The pod-like cocoons are made of silken threads and bits of leaf. Cocoons are found on trees, in plants nearby to where the caterpillar fed or in my terrarium.

Cecropias spend the winter in a cocoon. But all is not rosy in winter and cocoons spun in trees are often eaten by woodpeckers. Moths emerge in spring or more commonly in late June and July.

Adult moths can have a wingspan of 4 ¼-6 inches. Cecropias are a study in orange, red, brown and blue. The wings have crescent shaped marks and eyespots - fake eyes to scare off the birds. Adult moths live a week to 12 days. In that amount of time he/she has to find a mate, the female has to find a suitable place to lay eggs and they have to do all of this in the dark. Now here is an example of real speed dating.

According to Field Guide to Silkmoths of Illinois these once common moths are suffering a decline in populations due to an introduced parasitic fly. The fly was imported to the U.S. to control gypsy moth, but unfortunately has found silkmoth caterpillars a worthy substitute.

Although adult silkmoths may not feed during their short lifetime, other moths do feed on flower nectar. Large sphinx moths can be found fluttering around petunias at dusk. Or the smaller hummingbird moth is seen during the day living up to its namesake. Many of the flowers that butterflies visit will also be visited by moths. In some areas of the world, flowers reveal themselves only at night to their moth pollinators.

Tonight linger outdoors. You may get a glimpse of a debutante of the dark.

A useful reference is the Field Guide to the Silkmoths of Illinois by John Bouseman and James Sternburg. Available for $19.95 along with several other field guides on amphibians and reptiles, butterflies and freshwater mussels from the Illinois Natural History Survey PH: 217-333-6880 or http://www.inhs.uiuc.edu/chf/pub/manual.php

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