We need to talk about butterflies. Specifically, the monarch, Danaus plexipus. Do you realize the miraculous nature of the life of a monarch? I don’t use that term lightly. The wonder of the monarch goes beyond the familiar nature of insect’s ability to undergo metamorphosis, which in and of itself, pretty cool. We’re all familiar with the transition from caterpillar to butterfly.
An adult monarch butterfly in Northern Mexico or Southern U.S. lays eggs on a milkweed plant in the spring. It only lays eggs on milkweed plants. Ingesting the milkweed toxins is what makes the monarch so distasteful to predators. What a wonder of evolution that behavior is. Toxic enough to make the predator ill, but not kill it so that it learns to avoid orange and black insects. Doesn’t do much for the monarch eaten but does for the population of the species. The life of the monarch from this trait to its reproduction, to its migration are all lessons in communal good.
The egg takes 4 – 6 days to hatch. Then the caterpillar (larva) lives 2 – 3 weeks on the milkweed. The very hungry caterpillar munches away and grows from the emerged small larva to the familiar caterpillar, going through multiple molts as it increases in size. The caterpillar picks a spot, hooks on, and forms the familiar chrysalis, hanging from the underside of the leaf. This is the pupa. Honestly, what a disgusting sounding word, no? Say it a few times. Just sounds wrong, but this is where the true “magic” occurs. Once this creature has cocooned itself, enzymes are released and the creature begins digesting itself the caterpillar’s organized body is converted into a goo, which then organizes into collections of embryonic “imaginal” cells and eventually into the butterfly.
For a time, then this living thing goes from a self-sustaining, complex system of cells, tissues, and body systems to a bag of cellular goo, which then reorganizes itself into a new, different complex living system; yet, it is still the same life form, the same individual with the same genetic code. Through it all there is this essence of life that persists, or could cease to exist, if conditions are not favorable, with emergent properties—more than just a collection of cellular parts, to goo, to parts again. The butterfly emerges, hangs there for a bit pumping fluid into its wings, inflating them and then flying off (usually northward) as an adult.
But wait, there is more to this story!
This first generation of butterfly only lives for 2 – 5 weeks, slowing working its way further north before it finds a mate and lays eggs for the cycle to repeat itself again. This happens again and the 3rd generation moves further north still during its 2 – 5-week life, mating and producing more eggs. Finally, the 4th generation monarch emerges on a milkweed, maybe 1500 miles north of the Mexican mountains where its great-great grandparents spent the previous winter. This has all occurred in a few months.
But wait, there’s even more to this story?
The final amazing feat of the monarch begins here in North America as the 4th generation it starts migrating (not in 3 generations like those that brought it there) but in its one lifetime back to the mountains of Mexico. Keep in mind that individual, nor its parents, or even grandparents have ever seen those mountains before. Still, it finds its way “home.” Four generations to complete a migratory life cycle. Amazing. There’s complexity of organization that I find absolutely astounding. Life. What a fucking miracle.
2 thoughts on “We Need To Talk About The Monarch Butterfly”
Woven into a great novel by Barbara Kingsolver – Flight behaviour