It’s always exciting to see a new species of plant or animal, especially one that’s considered rare in your area. This happened to me earlier this month, when a Giant Swallowtail butterfly (Papilio cresphontes) visited my northern New Jersey backyard. This large, attractive butterfly is common in Florida, but becomes less abundant farther north.
The Giant Swallowtail is large, with a wingspan of four to six inches. The top of its wings are dark brown with two rows of yellow spots that cross at the tips of the forewings. Beneath, the wings are mostly pale yellow.
Northern populations wax and wane and wax again
From the last half of the 20th century until about five years ago, the Giant Swallowtail was rarely seen in New Jersey and nearby states. This reversed a trend of the late 19th and early 20th centuries when the Giant Swallowtail was reported to be increasing in the northern states. In 1892, the State Entomologist for New York wrote this about the Giant Swallowtail,
“It has gradually extended its range until now it occurs as far north as the vicinity of Montreal in Canada. The first record of its appearance in the State of New York was in 1864. Within late years, from being an occasional visitor, it seems to have established itself in Westchester county, and at Poughkeepsie. In other localities in the State it is occasionally abundant …”
In How to Know the Butterflies, published in 1904, John and Anna Comstock also wrote about the northward movement of the Giant Swallowtail, with a lyricism not seen in today’s field guides,
“On broad and leisurely wing the giant papilio is invading the North. It is still sufficiently rare in the New England and Middle States, so that there the heart of the butterfly lover stands still when he gets a glimpse of these magnificent black wings crossed with brilliant yellow, wings that look on the under side as if they were lined with some delicate lemon-colored fabric which allows the markings to show through.”
In the 1950s, sightings of the Giant Swallowtail in northeastern North America began to decline. The decline may have resulted from widespread pesticide spraying for the nonnative gypsy moth caterpillars that were defoliating the forests.
In doing research for this post, I learned that, in the last five years or so, the Giant Swallowtail is again on the increase in northeastern North America. The Giant Swallowtail in my backyard wasn’t as rare as I had initially thought.
Stay tuned for my next post which will be about the larval host plants of the Giant Swallowtail.
Thank you for another informative and timely post. Giant Swallowtails are being seen here in CT, too. Don’t you just love the Comstocks, especially Anna?
Diane Tucker
Thanks for your comment, Diane. This seems to be a banner year for the Giant Swallowtail. And I do enjoy the writings of the Comstocks and other naturalists of their era.
I’ll have to keep my eyes open for that one!
Thanks for your comment, natureintheburbs. Hope you get to see one!
Saw one in our Henrietta (Rochester area), NY garden a few days ago. It was awesome and I knew I hadn’t seen one like that before. I’ve been putting in butterfly/moth friendly gardens the last 3 years (including host plants) and this sighting, along with that of a hummingbird moth (also a first here in my gardens), made me feel that my efforts are coming to fruition. Yea!
Thanks for helping me identify it!
Thanks for your comment, Karen. It’s great that you’re reaping the benefits of your butterfly and moth garden. I saw a giant swallowtail in my garden again this year, on June 9. I wondered if it was an offspring of last year’s visitor.
I’ve seen many of these in the last few weeks, including several while kayaking Seneca Lake in upstate New York. I remember my disbelief when a mentor of mine in grade school said she had a population on her property in Loudon County, VA.
Thanks for your comment, joegorman, and I’m glad you’ve seen giant swallowtails.
I’ve seen many of these in the last few weeks, including several while kayaking Seneca Lake in upstate New York. I remember my disbelief when a mentor of mine in grade school said she had a population on her property in Loudon County, VA.
I have had two of these swallowtail butterflies in my yard the last few days in Northern N.Y. Hailesboro
Thanks for your comment, Linda. It’ll be interesting to see if the giant swallowtails continue to show up in the northern states in future years.
You can add Rhode Island to the list of places it is visiting. Here are a few pictures of a Giant Swallowtail visiting our butterfly weed.
Thanks for your comment. I’m glad you got to see one of these beautiful butterflies.
Saw a giant swallowtail on my butterfly bush on 8/31/13. First adult I’d seen in NJ, although I had a caterpillar last year on my Ruta graveolens.
I live in Brighton, Ontario and last year was the first time I saw the Giant Swallowtail. I kept reading about them and now have 5 giant caterpillars ready to pupate. Then I will keep them in the fridge over the winter. Hope it works.
Thanks for your comment. Hope you succeed with the pupae.