Since 1996, the population of monarch butterflies in the Eastern United States has declined by about 90%, and one of the biggest reasons is loss of habitat. Monarchs need early successional vegetation, with all the various flowering plants, such as goldenrod and milkweed, that often can be found in fallow fields, such as fields that are set aside in the CREP Program. During the warmer months, monarchs can be observed flying across fields in search of bright flowering blooms as the adults feed on the nectar from various flowers. Monarchs in the caterpillar stage feed exclusively on milkweeds.
Over the past several years, I have observed an increasing spread of milkweeds and goldenrods in fields that have been included in the CREP Program. Some songbirds nest in these fields, and deer will occasionally feed through them in search of certain plants they like. Rodents, such as mice and moles, frequent these plots to provide them with unlimited food and shelter. Along with these creatures, these abandoned fields are increasingly frequented by monarch butterflies.
The adult monarchs (Danaus plexippus) fly about and feed on the nectar of the goldenrod flowers, while the caterpillars, or larvae, slowly munch away on the leaves of the milkweeds. The butterfly’s chrysalis form, or pupa stage, can be observed hanging on the underside of leaves and branches and attached to structures nearby.
The monarch butterfly is easily recognizable, with a wingspan of about 4 inches and its basic coloration of orange wings, marked with black veins and a black border with two rows of white spots. While there are several 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.
While they can be seen all across our state, they are currently most often spotted feeding on the nectar of goldenrod plants 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. The most amazing aspect of this flight is that it will take them about 1,800 miles!
As a retired former airline pilot and having flown large jet aircraft across the Pacific and Atlantic oceans, I understand navigation and have a real appreciation for 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, and a new generation hatches and matures, 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 4 generations of monarchs occur each year. The eggs that the monarchs lay will transition through the life cycle, providing some of the millions of migrating to Mexico. 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.
One of the best ways we can help the monarch butterflies and (hopefully) increase their numbers throughout the state is to not mow all of our fields but allow some to go fallow and thus permit goldenrod and milkweed to propagate and flourish. These added “abandoned” fields will add much-needed food sources as well as propagation areas for the magnificent butterflies. These fallow fields will provide additional habitat for numerous birds and mammals.
There exists today 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: athttps://monarchjointventure.org/.
