The Endangered Monarch Butterfly

Sally Sisson Anderson — Artist in Residence, Western Wildlife Corridor.

Two years ago I raised several monarch caterpillars to maturity, saw them go into their chrysalises, and then watched the butterflies fly away. I know of other people from the Western Wildlife Corridor who did the same thing. This summer I saw no monarchs fly through my yard in Harrison. I had no eggs laid on my milkweed plants. Since then I have seen only one Monarch, and it did not stop to lay eggs on my plants.

Books tell us that the Monarch Butterfly is a beautiful orange and black butterfly known for its long annual migrations and that the Monarchs are concentrated in North and South America. There are some also found in Australia, Hawaii, India, and other locations. The Viceroy mimics the Monarch, which is unpalatable to its predators – birds. Therefore, the birds do not eat either butterfly. The Monarch is unpalatable because its caterpillars will eat only milkweed. There are several species of milkweed. The ones in our area include the common milkweed, the honey vine, and the orange butterfly weed. Milkweed plants produce milky juices that contain toxic compounds called cardenolides which are stored in the voracious caterpillar’s body and make the larva and the butterfly distasteful to predators. The caterpillar has several molts and attains a length of about two inches.

Monarch Butterfly sketch by Sally Sisson Anderson

The fully grown caterpillar leaves the milkweed plant to pupate elsewhere as a pale green chrysalis with golden spots. After 10 – 14 days the chrysalis becomes transparent and the butterfly soon emerges, feeding on a variety of nectar sources. Monarchs live 4-5 weeks, except for those that overwinter in Mexico, which live 7-9 months.

Once thousands of migrating Monarchs gathered in autumn and migrated southward sometimes traveling hundreds of miles or more to over-winter in Mexico or California. Upon reaching their destination, they gathered in sheltered sites, like on trees where they clustered on trunks to hibernate. In Spring the Monarchs began their journey North, feeding on nectar along the way, and laying eggs. Some of the returning butterflies were members of the first generation, others are the next generation to develop from the over-wintering insects. And so it goes, as the Monarchs progress northward up over the country, and over the weeks of Summer. Eggs are laid on Milkweed plants along the way. But, if there are no Milkweed plants because of the mowed green grass of subdivisions on their flight coming north through America, the Monarch will die out.

Do Monarchs eat the same thing everywhere they live in North America? Yes and no. Larva eats Milkweed as food, but adults will need nectar from different flowering plants. There are several species of Milkweed and Monarchs larvae will eat most of them. For instance, they will eat butterfly weed as well the Milkweed, and they will eat the honey vine, another species of milkweed. There are several different milkweeds they will eat in different parts of the country.

Things you can do. You can plant a strip of land in your backyard with Milkweed and other pollinator flowers like Queen Ann’s Lace, Coneflowers, New England Asters, Orange Butterfly Weed, the Sunflower family, Monarda or bee balm, Mountain Mint, Dog Bane, Zinnias, Butterfly Bush, Joe-Pye Weed, and Verbena to name a few.

When we were vacationing in Virginia and North Carolina we saw fields of milkweed and other wildflowers in the parks. Even the roadsides were left wild with milkweeds growing. This would be a perfect world for the Monarchs! Perhaps we could contact the parks and the highway department about planting milkweed groves.

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