Marlinton/White Sulphur District Ranger’s Report -Part 1, Monarch Butterflies
By District Ranger Cindy Sandeno
Here we are in August, that mysterious month that isn’t quite summer and isn’t quite fall, but somewhere in between. Driving around the forest, you start to see that our summer flowers like Bee Balm, Black Eyed Susan, and Joe Pye Weed are starting to reach their peak, and maybe even fading a bit, and they’re being replaced by the rich colors of yellow and purple of our showy fall flowers. All around us the fields are beginning to turn into a lovely tapestry of Ironweed, Asters and Goldenrod. This is the time of year when one of the most fascinating of all biological processes is occurring. The final generation of Monarch Butterflies are completing their transformation from egg to caterpillar to pupa to the super generation of Monarch Butterflies that will migrate over two thousand miles to their winter home in the Sierra Mountains of Mexico. Monarch Butterflies are among the most beautiful and familiar butterflies we have in West Virginia. You’ve probably seen them with their black bodies and wings that are a kind of orangish brown to red color with black veins running throughout and a few white spots along the border.
Let’s start with the marvelous metamorphosis of the Monarch Butterfly. Female Monarchs usually lay a single egg on a milkweed plant and each egg is formed inside the female before she lays it and it has a hard outer shell that protects the developing larvae inside. The shell is lined with a layer of wax which helps keep the egg from drying out. A Monarch stays in an egg stage for about three to four days, and from that egg emerges a caterpillar. That’s the second stage of this amazing metamorphosis. It is during this stage that monarchs do all of their growing. In fact, that’s about all they do. They begin life by eating their egg shell and then they continue to eat the milkweed plant on which they were laid. When the caterpillar has become too large for its skin, it molts – or it sheds its skin- similar to what a snake does. At first the new skin is very soft and it doesn’t provide a lot of protection but then it hardens and molds itself to the caterpillar. Now the caterpillar often eats the shed before starting on the milkweed plant, and every time it molts, it’s called an “instar.” So the Monarch caterpillar actually goes through five stages of being a caterpillar or five stages of an instar, and it all happens within a period of ten to fourteen days. As the caterpillar sheds its skin for the last time, it attaches to the stem of the plant or the leaf and it forms what is called a pupa or chrysalis. During this papal stage, the transformation from a larva to an adult is finally completed. And this stage lasts from about ten to fourteen days. And just before the Monarch emerges from the pupa you can actually see the black, orange and white wing patterns through the pupa covering. And finally the butterfly emerges, completing this amazing life cycle.
Now, normally when Monarchs emerge, their only thought is about reproducing, but right now, in mid to late August, you have what is called the “super generation of Monarchs.” When they emerge, they have a very different job. They have to migrate to the over-wintering grounds in central Mexico.
In Part two of this story we will talk about that amazing migration to Mexico, a journey that can span as far as three thousand miles.
For Allegheny Mountain Radio, this is District Ranger Sandy Sandeno on the Marlinton/white Sulphur District, Monongahela National Forest.