Throughout most of the year on St. Simons Island, butterflies can be seen gathering nectar or flying along roadsides and waters’ edges. The fall in particular is a great time to spot butterflies along their migrations. These beautiful creatures come in a spectacular range of colors and the gulf fritillary is no exception, with its bright orange wings and iridescent silver spots.
Gulf fritillary butterflies, Agraulis vanillae, get their name from their great migration southward over the Gulf of Mexico. They are also known as the passion butterflies because of their affinity to passion vines. These brush-footed butterflies have small hairs along their legs to smell and taste with, and are considered to be a medium-sized butterfly, with a wingspan that can reach up to three and a quarter inches. With long, narrow wings that are mostly orange with black and silver markings, the gulf fritillary butterflies are commonly mistaken as monarch butterflies, but they are much smaller and can be mostly distinguished by their iridescent silver spots.
They can be found in a number of natural sunny spaces, from fields, open wooded lands, and pastures to yards, parks and even beaches. They are mostly located in the Southern areas of the United States, yet they have been found all the way up to San Francisco and even into South America. These butterflies have seasonal distributions, heading north for the summer breeding months and then south for the winters. In our area, gulf fritillaries begin one phase of their seasonal migrations in the fall. They head southward, whether over the Gulf of Mexico or into parts of Florida, and winter in areas where it does not frost over. When the spring hits, they move back into our areas and northward to form breeding colonies.
Female gulf fritillaries can produce multiple generations each year. They will only lay their tiny yellow eggs singularly on the leaves, stems and tendrils of the passion vine. The larvae, once hatched out of the eggs, will reach up to four centimeters long. They are bright orange with black spines. The spines are not poisonous to the touch, but are poisonous if consumed by predators. The larvae will feed on the passion plant host, at times almost completely destroying the plant. After about 30 days, the larvae form into the pupa stage. They hang upside down on the passion plant and create their cocoons. The pupa look very much like the other dead leaves on a passion plant. They are brown and can reach up to three centimeters long. They will stay in this form between 10-20 days, before they emerge as a beautiful butterfly. Once fully grown, the butterflies will eat nectar from flowering plants such as lantana, shepherd’s needle, cordias and composites.
On St. Simons Island, it is very easy to cultivate and encourage the reproduction of these beautiful butterflies. Planting many different passion vine plants in your garden is a great step to attract them to your yard. Take note of the type of passion vine because a couple of species are poisonous to the gulf fritillaries, such as the red passion vine. Make sure that you plant a few of them, because once the larvae hatch, they are ravenous.
By Kathleen McMenamin Vicars, Master Naturalist
The H2O Nature Center is a great place to spark curiosity and inspire learning in all ages, offering eco-adventure tours and live alligator exhibits. To make reservations for the Alligator and Wildlife Tour, please call 843-686-5323. For details on other water activities offered by H2O Sports, visit H2OSports.com.