An eastern tiger swallowtail

Butterflies, moths clearly differ



You never know when nature is going to surprise you with a special treat as you go out and about woods and fields. Just outside a friend’s house on a flowering rhododendron, they discovered abundant tiger swallowtail butterflies. These gorgeous butterflies are very colorful, and their color can vary sometimes, although, locally these lovely butterflies are yellow or yellow-orange with black tiger stripes. Their Latin name is Papilio glaucus.

The adults eat nectar from flowers, and they especially like butterfly bush, milkweed, Japanese honeysuckle, phlox, ironweed and wild cherry.

The caterpillar of the tiger swallowtail is very interesting to see and tries to look fierce in order to scare away it many enemies. This green caterpillar has a large head on which are two black dots surrounded by yellow rings. This is to scare away the enemies and make them think the caterpillar is fiercer than it is. Eastern tiger swallowtails are pretty much loners but males do fly about looking for a mate. These butterflies have an interesting life history. When you find them feasting on a plant, have your camera ready for great photo opportunities.

At another reader’s house one night, a large handsome cecropia moth landed on a screen door. Moths and butterflies do differ in several ways. Moths have antennae that are shaped like feathers, and their legs are stocky and fuzzy. Their bodies are plump and very fuzzy, and moths fly mostly at night.

Butterflies have threadlike antennae with knobs at the ends. Their legs are thin and usually hairless. A butterfly’s body is hairless and usually smooth, and they are active during daylight hours.

The beautiful cecropia moth has a wingspan equal to that of a small bird; it is impressive. These giant silk moths are short lived. They live for only a week or two. After mating, the female lays more than 100 eggs in the next couple of weeks and then dies.

Cecropia caterpillars are equally interesting to see. When it’s mature, the caterpillar is covered with red, yellow and blue spiked knobs. It spins a cocoon and molts inside of this one last time. Consult a good butterfly and moth book or go online to see some wonderful photos of these interesting creatures and their whole life history. I strongly recommend “The Secret Life of Backyard Bugs” by Burris and Richards, published by Storey Publishing of North Adams, Mass.

This week was exciting for me, for my latest book “Living on the Edge,” co-authored with Thomas F. Vining, was just published and is now available online as well as from the authors.

The attractive book is one to take with you as you explore the shores of Mount Desert Island and other seashores in New England. With it, you can identify what you find. It is definitely a guide book to tide pool animals, seaweeds and seaside plants. Make your walk along the shore an adventure!

I think tide pools always fascinate beach walkers, for they are full of surprises. As the tides go in and out, these temporary pools change so they are always of interest. Probably for the young adventurers, the finding of a starfish, crab, sea urchin or sea cucumber is the best, but the mosses and seaweeds also are fascinating.

My best adventure one day was at the tide line where the seaweed piles up as the sea comes and goes. As is my practice, I always turn things over to see what might be found lurking or hiding beneath these wet fronds. To my pleasant surprise I discovered a bryozoan colony called “sea lace,” one I had never seen before. At that moment, I didn’t know what it was, but I did have my hand lens with me and examined it closely. It made me think I was looking at Dr. Seuss’ Whoville. Living on this blade of seaweed was a bryozoan (moss animal) village. You needed a hand lens to see all the details.

On the kelp frond I had found was this grayish-white crust clinging tightly to the kelp. Some colonies can be tight, like sea lace, others can be soft, tufted and branching. There are about 5,000 living species of bryozoans, but because of their minute size, they are mostly overlooked. Although most are found in saltwater, some do occur in freshwater. They are usually found in shallow water, but they can be found to depths of as great as 8,200 meters. As you walk along the shores of MDI, take time to look under the rocks and seaweeds, turn things over, really explore.

Bryozoans are considered a nuisance on the bottom of ships, pilings, piers and docks, yet they produce a remarkable variety of chemical compounds, some of which have been useful in medicine. A common marine bryozoan is the source of the drug bryostatin l, tested as an anticancer drug.

Enjoy the woods, fields, shores, mountains and waters of MDI at this wonderful time of year. June is busting out all over.

Ruth Grierson

Ruth Grierson

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Send any questions or observations to [email protected] or call 244-3742.
Ruth Grierson

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