Our State Insect: The Monarch Butterfly
By Lisa Olson, Master Gardener
The days are getting shorter, the leaves are changing, some days there is a noticeable chill in the air. Time to head south before the snow flies. I’m not talking about Minnesotans who’ve experienced one too many frigid winters, but rather the Minnesota state butterfly, the monarch. Click here to read fascinating facts about the monarch butterfly, renowned for its extraordinary migration.
Since March 31, 2000, the monarch butterfly has represented Minnesota as the state butterfly after being promoted by a fourth-grade class at Anderson Elementary School in Mahtomedi, Minnesota. It was a popular choice. Elementary schools in six other states convinced their state legislatures to adopt the monarch as their state butterfly as well.
Though monarch butterflies can be seen all over North America, from Canada to Mexico, the eastern monarch butterfly numbers have dropped drastically over the last few decades. In fact, on July 21, 2022, the International Union for Conservation of Nature declared the monarch as endangered, threatened by habitat destruction and climate change. However, the monarch is not protected by the Endangered Species Act (ESA) because the US Fish and Wildlife Service has not yet determined the monarch belongs on the protected list. Most creatures on the ESA list have very localized habitats, whereas the monarch is widespread, making it difficult to enforce protection of its habitat.
To understand the range of the monarch, it is important to look at the life cycle of the insect. The Latin name for the monarch butterfly is Danaus plexippus, which literally means sleepy transformation. The monarch undergoes a complete metamorphosis from egg, to larva (caterpillar), then pupa (chrysalis), and finally the adult stage. The egg and caterpillar stages occur only on species of milkweed (genus Asclepias), whereas adults survive on the nectar from a variety of flowering plants. In a single year, there will be 4 to 5 generations of monarchs. A butterfly lays one egg at a time, roughly the size of a pinhead or pencil tip. But throughout their lifespan a female lays an average of 300-500 eggs specifically on milkweed plants so that the caterpillars will emerge directly on their only source of food. During the caterpillar stage, they simply eat, rest, and grow until they form into a chrysalis from which they finally emerge as a butterfly to begin the cycle all over again.
The monarch life cycle
The transformation from egg to adult takes about a month, and then they live only two to six weeks as adults, where their main focus is laying eggs to build their population throughout the summer. That is until the last generation of the season. This super generation is the group of butterflies that make the long journey all the way to Mexico along with tens of millions of other monarchs. This generation may live up to eight or nine months! Tags or modern sensors have been placed on monarchs to gather data about the amazing journey that takes them from as far north as Canada thousands of miles to their winter home in Mexico, or in California in the case of the western Monarchs.
Upon reaching their destination west of Mexico City, they flutter around in the warmth of the sun by day, and at night they huddle together covering entire trees. In the spring, they make the journey north laying eggs on milkweed plants along the way. To experience for yourself the magical sight of millions of monarchs wintering in Mexico, consider traveling with the Minnesota Landscape Arboretum’s curator of endangered plants on Kingdom of Monarchs | Minnesota Landscape Arboretum trip to Mexico in February 2024.
In the days ahead, be on the lookout for the last stragglers beginning their long journey south to Mexico. The easiest way to tell the difference between a male and female monarch, is to note the presence of black dots on each of the male’s wings or the lack of dots on the female. Ponder the long road ahead for these magnificent creatures and perhaps how you can help them thrive in the future. Consider creating or enhancing a pollinator habitat in your yard or community. Identify a sunny location, prepare the site for sowing native seeds or installing native plants, plant, and continue to conduct maintenance to provide a healthy habitat. Check out Minnesota Zoo for a list of Minnesota native pollinator favorites. For additional resources for monarch fans of all ages, visit monarch joint venture.
Resources for this article:
Photo credits: Lisa Olson, Master Gardener (1), Monarch Joint Venture
https://monarchjointventure.org/monarch-biology/life-cycle (2), Monarch Joint Venture