For several years, on a nearby property, I have been observing an increasing spread of milkweeds and goldenrods in fields that have been placed in the CREP Program. Some songbirds nest in these fields, deer will occasionally feed through them in search of certain plants that they like, and rodents, such as mice and moles, frequent these plots, which provide them unlimited food and shelter. Along with these creatures, these abandoned fields are increasingly frequented by monarch butterflies.
In recent weeks, the adult monarchs (Danaus plexippus) have been flying about and feeding on the nectar of the goldenrod flowers, while the caterpillars, or larva, have been slowly munching away on the leaves of the milkweeds and the chrysalis form, or pupa stage, of the butterfly can be observed hanging on the underside of leaves and branches and attached to structures nearby.
The Monarch butterfly is a member of the classification of butterflies known as “Milkweed Butterflies” and is easily recognizable, with a wingspan of about 3 to 4 inches and its basic coloration of orange wings, marked with black veins and a black border with two rows of white spots. Because the caterpillars of the Monarch feed on toxic milkweeds, the adult butterflies are distasteful to birds, thereby gaining some protection from predators. While there are numerous subspecies of monarchs, the ones we see throughout Pennsylvania can also be found across the entire United States and occasionally on islands in the Caribbean. A similar butterfly that is sometimes confused with the Monarch is the Yellow Swallowtail, also found throughout Pennsylvania; its coloration is a pale yellow, whereas the Monarch is orange. It can often be seen feeding in the same area as the Monarchs.
While Monarch butterflies can be seen all across our state, they are most often spotted feeding on the nectar of goldenrod plants in meadows and weedy fields as they gather their strength for what is truly one of the Wonders of the World of Nature. As the temperatures begin to drop in autumn, they will gather for their migration southward. One of the best-known butterflies, the Monarch, is the only butterfly that annually migrates both north and south as birds do regularly. But no single individual makes the entire round trip. The most fantastic aspect of this flight is that it will take them about 1,800 miles!
As a retired former airline pilot who has flown large jet aircraft across the Pacific and Atlantic oceans, I understand navigation and genuinely appreciate today’s sophisticated navigational equipment. So how, for Heaven’s sake, does all of this modern technology fit inside this small insect?!?! Well, obviously, it doesn’t, but somehow, through the magic of nature, they will fly from the fields of Pennsylvania this fall and winter in the mountains of Mexico, then return to our state in the spring, where the cycle begins all over again! Eggs will be laid on milkweed plants, a new generation hatches and mature, and the life cycle continues. As these eggs hatch, and after several molts, the black, white, and yellow-green striped caterpillar reaches almost 2 inches. It then leaves its milkweed plant to pupate elsewhere as a pale green, golden-dotted chrysalis. Adults live only a few weeks, except for those that migrate south and winter over in Mexico, which live seven to nine months. Therefore, about four generations of monarchs occur each year.
This time of year, I can glance out my window to see a monarch butterfly winging its way from one goldenrod plant or milkweed plant to another. No doubt, it will not migrate to Mexico, but the eggs it lays will transition through the life cycle, providing one of the many millions of ones that do. Thinking about the amazing migration that will occur, the stay over the winter in Mexico, with a return in the spring, gives a renewed appreciation for the Wonders of Nature.
Today, there exists an organization, The Monarch Joint Venture, a nonprofit made up of federal and state agencies, non-governmental organizations, businesses, and academic program partners working together to conserve the monarch butterfly migration for future generations. For more information, contact them at https://monarchjointventure.org/.
