Mating Behavior

Life cycles are continuous, lacking a definitive beginning or end, allowing us to explore them from any point. I opted to start with the mating behavior of Monarchs—a sight I had never witnessed in over twenty years of conservation efforts until I captured it in 2020. On a late summer afternoon, high in a maple tree, I observed two Monarchs engaging in mating. The outcome of this union? Eggs.

Identifying Monarchs

Monarch butterflies can be distinguished by keen observers; males sport a distinctive black dot on each hind wing, which are scent glands thought to attract females.

The Egg Stage

Female Monarchs lay their eggs on milkweed plants, typically on the underside of leaves. This placement serves multiple protective purposes—shielding the eggs from harsh weather and camouflaging them from predators. It took me years of rearing Monarchs before I noticed an egg; they are minuscule, akin to a pencil tip, pale yellow, and ovoid with visible ribs under magnification.

The duration of the egg stage spans 3-5 days. Before the caterpillar emerges, its dark head can be discerned through the eggshell, leading me to mistakenly believe the egg had failed.

The Caterpillar Stage

Upon hatching, the caterpillar consumes its eggshell, which is rich in protein—giving it a nutritional boost. Monarchs exclusively lay their eggs on milkweed, the only food source for the caterpillars.

In 1999, when I began my journey into Monarch education, many were unaware of this fact. The caterpillar stage, or stage two in the Monarch’s life cycle, lasts around two weeks. During this period, the larva feeds voraciously on milkweed, shedding its skin five times as it grows, with these stages referred to as instars.

Tiny monarch caterpillar. Photo by author. © Carol Labuzzetta, 2018. All Rights Reserved.

The Chrysalis Phase

The chrysalis stage typically lasts about ten days, influenced by environmental factors. Initially, it appears green due to its contents, but as days pass, the metamorphosis becomes visible, with the Monarch's wings gradually becoming apparent through the transparent casing.

When ready to emerge, a process known as eclosing takes place—an incredible spectacle that occurs rapidly. For many years, I struggled to capture this moment on video. However, with patience, I learned to anticipate the emergence, which usually occurs roughly 24 hours after the wing pigments become visible.

Witness the fascinating emergence of Monarchs in this video, featuring a beautiful piano background played by my son.

Wing Drying and Identification

After emerging, Monarchs need time for their wings to dry, a process that can take several hours. This interval is ideal for observing and identifying the butterfly's sex and size. They do not require immediate nourishment, allowing for careful observations before release.

In the autumn, during the last generation of Monarchs, tagging becomes possible. I participated in this for seven seasons until last year. More information on tagging can be found on the Monarch Watch website, a valuable resource for engaging in their migration as citizen scientists.

Human Impact on Monarchs

The threats facing Monarchs are multifaceted, with human activities at the core. Habitat destruction due to rapid urbanization, extensive pesticide use, and monoculture farming practices have all contributed to their decline.

My dedication to this iconic species has been fulfilling, and educating the public about their challenges is crucial. We must all recognize the impact of our actions on wildlife.

Inspiration and Further Reading

For more insights and photographs of milkweed, you can visit my personal blog, The Apples in My Orchard on WordPress, where I have been writing since February 2017.

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