Think about it. The Monarch butterflies that are arriving now by the millions in the mountains of Mexico were born on the underside of a milkweed leaf in North America. If all went well, some of those leaves and butterflies were in my backyard in the Maryland Piedmont.
Monarch adults — butterflies on the wing — can feed on any nectar, but Monarch caterpillars can only feed on milkweed. I offer both milkweed and a succession of nectar plants in my yard.
It’s estimated that only one in ten Monarch eggs successfully reaches adult butterfly stage. To improve those odds, I reared Monarch eggs and caterpillars that I found in my yard, protecting and feeding them in airy enclosures. Eighteen out of 22 Monarch eggs and caterpillars made it to adulthood and flew away. (I tip my hat to Monarch champions who raise hundreds each year from eggs and caterpillars found in fields and roadsides.)
Here are a few scenes from this summer’s Monarch adventure: egg, five caterpillar stages of growth, chrysalis stage, and adult butterfly.
This Monarch is laying eggs. I followed her path, collected and successfully reared six of her eggs.
Monarch eggs, laid one per leaf, are hard to find and harder to photograph. Eggs hatch after three to five days.
Incredibly tiny, just-hatched Monarch caterpillar. Called a 1st instar, it will eat its shell.
1st instar Monarch caterpillars eat a tiny pattern in milkweed leaves.
Monarch caterpillars shed their skins with each new instar. These are 2nd instar.
Still small, but growing. Their antennae are longer at this stage.
Larger and eating lots of fresh milkweed every day. Their antennae extend beyond their heads at this stage.
Growing and eating, Monarchs remain in caterpillar stage about two weeks.
At 5th and last instar, caterpillars are plump and their antennae are more than 1/4 the length of their bodies. Soon they will form a chrysalis.
When ready to pupate, a Monarch caterpillar climbs to a high spot, fixes itself to a surface with silk, and drops to a “J” before shedding its skin one more time to form a chrysalis.
It takes a Monarch caterpillar about two weeks to transform to an adult butterfly. Wings become visible in the chrysalis as the time to emerge approaches.
The chrysalis is transparent right before the butterfly ecloses, i.e., emerges.
Butterflies need a couple hours for their wings to harden and strengthen for flight.
Monarch female gathering strength in an enclosure
Monarchs don’t need to eat for 24 hours after eclosure. This one was offered watermelon fast food when cool and rainy weather delayed release.
Two Monarchs, tagged for tracking as part of Monarch Watch, ready for take-off
Monarchs that emerge in late August to October are the “super generation” that migrates to overwinter in Mexico. They will resume their journey in the spring, beginning a new generation in the southern US. That generation will bear another generation, with several successive and shorter-lived generations continuing north until the next “super generation.”
You can help Monarchs! Plant milkweed for caterpillars and flowers that are good sources of nectar for butterflies. Monarchs especially need gardeners to grow flowers that bloom in late summer and autumn, when many gardens have passed peak, to fuel their journey to Mexico. Think asters, zinnias, cosmos, lantana, Montauk daisies. Find Monarch Watch’s plant list here. You’ll be rewarded with butterflies.