By Terri Estes
The monarch butterfly is probably the world’s best-known butterfly. The monarch is known for its vibrant orange and black markings, which serve as a warning signal to predators that monarch butterflies are toxic. The toxicity is a result of chemicals obtained from the milkweed plants they feed on during their larval stage. The black borders and veins on the wings provide a striking contrast to the orange background. The upper side of the wings also have white spots along the border. The larvae, also known as caterpillars, are black, white and yellow striped and can often be found feeding on milkweed plants.
The migration pattern of the monarch butterfly is truly remarkable. The monarch has multiple generations during the summer. The last few generations of monarchs that hatch in late summer and fall are unique. These butterflies undergo a process called “diapause” which essentially means that they put their reproductive development on hold. Instead of laying eggs and continuing to breed, these monarchs start to store up fat reserves in preparation for their long migration. They will travel up to 3,000 miles during this fall migration. The East Coast population of monarchs will travel to Mexico, while the West Coast monarchs will overwinter in Southern California.
In recent years, both the eastern and western populations of the monarch have plummeted. According to the U.S. Fish and Wildlife Service, the monarch population has dropped by 88 percent since 1996. In 1996, the estimated population was 383 million. In 2020 the estimated population was just under 45 million. The decline is influenced by many contributing factors such as loss of habitat, loss of milkweed, which is crucial for monarch reproduction, and pesticide use. The milkweed plant is so important because it serves as the sole host plant for the monarch caterpillars as they feed exclusively on milkweed leaves. Adult monarchs feed on the nectar of many plants and flowers as they migrate and if there is a lack of flowering plants, they will not survive the migration.
The Long Island region serves as an important stopover for migrating monarch butterflies on their trek to Mexico. The Island’s relatively milder climate and available resources, including late blooming flowers, makes it an attractive location for monarchs to pause on their journey. As a child, I remember the sand dunes in Breezy would be filled with monarchs towards the end of summer. Now, they are a relatively rare siting.
Efforts are underway to protect and conserve the monarch butterfly, but we can help. Plant a butterfly garden or plant some milkweeds in old flowerpots. There are more than 10 types of milkweeds, and some are very attractive. Your efforts will be rewarded by beautiful butterflies in your garden, and who doesn’t love butterflies?