New backyard butterfly: Heraclides cresphontes

There hasn’t been much to post about recently, with all the wind and clouds keeping photo ops to a minimum. The heliconians (zebras and julias) are still hanging out around my passionvines, and the blues are still festooning the scorpion tail. I’m also seeing sulphurs around, as I have been all summer—no surprise with False Tamarind (Lysiloma latisiliquum), the larval host tree of Large Orange Sulphur (Phoebis agarithe), on the premises—but trying to get a picture of those strong and erratic fliers is like trying to get a picture of the wind itself.

I’ve also been seeing a couple of large swallowtail species. One of them is the familiar Battus polydamas that I had around the old house, thanks to the robust Dutchman’s-pipe we had there. Here at the new house they drift over to our house from our across-the-street neighbors, who have a much smaller, but still quite productive, vine.

The other swallowtail I’m seeing now and again is the striking Heraclides cresphontes, Giant Swallowtail. It’s a two-toned beast, as you can see from the couple of snapshots below, taken back in 2008 when I was frequenting Fern Forest at lunchtime. In this one you can see the black upperside with the strong yellow spots, the hint of color on the tail and dorsal side of the abdomen:

But that’s nothing compared to the cream-colored underside, with the strongly marked blue median spot-band edged in orange, and the cream-colored abdomen:

I show these ancient photos because despite all my efforts here at home, I have yet to capture this butterfly on my camera’s digital chip.

These colorful butterflies nectar on just about anything, but they tend to favor areas that have their favorite larval food, which is just about any member of the citrus family (hence one of their other common names, “orangedog”). And as I was out hand-watering a few late-season transplants Monday night (a wild coffee, a gumbo limbo, and a firebush), I checked in on one of the first plantings that I put in, my Zanthoxylum fagara, also known as Wild Lime or Lime Prickly Ash. As its common name implies, it’s a member of the citrus family. And lo and behold, I saw what looked like a giant bird dropping! On closer inspection, though, that “bird poop” had shape, structure, and even what look like ocelli at the “head” end:

That’s no bird poop! That’s a giant caterpillar! Intimidating little bugger, innit?

And it’s not just any giant caterpillar: it’s literally a Giant Swallowtail caterpillar. This one looks to be about two weeks old, fourth instar, if the timeline on this website from way out west (Utah!) holds true for my area (which it might not; the humidity and extra daylight of subtropical Florida might favor rapid larval development).

Here are a couple more shots of this little guy. In this next one you can see the shiny skin that increases its resemblance to fresh bird poop. (And note the wicked thorn visible on the plant in this shot; that’s why I put this particular plant in the corner, where it wouldn’t get much traffic. I don’t want people getting stuck by those vicious spines!):

And this last shot actually shows most of the animal in focus; always a nice  effect to strive for in one’s nature photography. You know: focus!

One of my guides to butterfly caterpillars (Allen et al. 2005) says that this is the most likely of all citrus swallowtail caterpillars to occur in the garden, and recommends, before any other citrus tree, prickly ash (which is a close relative of wild lime). So I’m pretty confident of the ID on this little guy; I can’t wait to see the adult form!

Another of my caterpillar guides (Wagner 2005) notes that this is

a caterpillar with excellent options in both bird-dropping and snake-mimicry. When viewed head-on the later instar caterpillar passes as a credible snake mimic with scalelike markings all about the thorax. When viewed from the side and top its visage is that of a bird dropping, especially in early instars. Its shiny skin adds to the disguise, giving the larva the character of a freshly deposited dropping. (78)

And my third guide (Minno et al 2005) echoes the other two in noting that this is one of the more conspicuous and predictable caterpillars.

One note about the name: the genus to which this species is traditionally assigned (Papilio) is disputed. Some taxonomists prefer to split this large group into three or more genera, one of which is Heraclides, to which these “splitters” assign Giant Swallowtail. Others prefer the “traditional” classification of this animal as a member of Papilio, but they place it in the “Thoas” group (there actually is a Thoas Swallowtail, a rare visitor in extreme Southern Texas).

Two of my three caterpillar guides (all dated 2005—a banner year for caterpillar books, with one each from Oxford, UPF, and Princeton!) still list the Giant Swallowtail under Papilio (P. cresphontes), but Minno et al, brave taxonomists, list it under the new name, Heraclides. The insect conservation group the Xerces society follows this new taxonomy, at least based on their entry for a closely related species, Schaus’ Swallowtail:

Traditionally, all North American swallowtails were placed in the genus Papilio but were recently split between three genera. Papilio aristodemus was transferred to the genus Heraclides Hübner 1819.

I don’t have any skin in this game; I just want to know what to call the darn thing!

[UPDATE: The Heracleidae, of course, are the descendants of Hercules; Cresphontes is one of those people.]


Allen, T.J., J.P. Brock, and J. Glassberg. 2005. Caterpillars in the Field and Garden: A Field Guide to the Butterfly Caterpillars of North America. New York: Oxford UP.

Minno, M.C., J.F. Butler, and D. W. Hall. 2005. Florida Butterfly Caterpillars and Their Host Plants. Gainesville: UPF.

Wagner, D.L. 2005. Caterpillars of Eastern North America: A Guide to Identification and Natural History. Princeton, NJ: Princeton UP.