This week's butterfly is considered a success by conservationists, but it still includes one of America's most rare and vulnerable butterfly subspecies. At least, historically it has included...some sources now list Florida's Schaus' Swallowtail as a separate species from the Caribbean islands' Dusky Swallowtail.
Photo from Butterflies of America, by Bill Bouton, 2008.
Photo from Butterflies of America, by Bill Bouton, 2008--possibly the same individual? Males tend to show more vivid contrast between black and pale yellow; females can, as shown, have even the red, white, and blue spots muted into stylish shades of brown and gray.
Heraclides aristodemus was known by other names before 1911, but has been called Schaus' Swallowtail since Schaus published this description:
Only the subspecies ponceana (sometimes ponceanus), among the other subspecies of Heraclides aristodemus, was considered critically endangered, though all of these large butterflies are somewhat vulnerable. Some scientists argued that ponceana was distinctive enough that it ought to be considered a separate species; most have not agreed with this claim.
(Why is it either ponceana or ponceanus, but always and only aristodemus? Because Aristodemus, or Aristodemos, was an individual man's name--a soldier in the Iliad, one of those literary characters from whom older names for Swallowtails came. Ponceana or ponceanus refers to a place, though the place would have been named after Ponce de Leon and the traditional rule didn't say that all characters had to come from fiction; some others came from history.)
Some more notes on the namesakes of other Swallowtails:
Due to different sources' listing this species as Papilio aristodemus ponceanus, Heraclides aristodemus ponceana, or Heraclides ponceana, information about it--though abundant--is scattered around the Internet in a tedious and time-consuming way.
In flight it seems easy to confuse with other Heraclides--another very large Swallowtail, with fairly long tails, black or dark brown with yellow stripes above, yellow with black stripes and spots below.
This butterfly's habits are adapted to survive in groves. Its flight is typically high and erratic; it likes to lay eggs high in the trees, on new leaves. Schaus' Swallowtails can fly more than five miles across water, between Keys. They can also fly around tree branches and spiderwebs. They are not great composters; males are likely to amuse themselves by claiming a territory, often a tree about ten feet above the ground, and patrolling it rather than joining male drinking buddies at a puddle. (They do, of course, drink both fresh and salt water, but the males don't spend their days sipping salt water, as many Swallowtails do.) They usually avoid places that are subject to flooding.
They are even said to be able to stop in mid-air and fly backwards to confuse birds. This web site, without questioning the honor or the sobriety of people who claim to have observed this, does point out that most butterflies have been blown backwards by gusts of wind.
Some sources, such as Butterflies of America, accept the US-centric proposed reclassification of this species with H. ponceana ponceana (also called H.a. ponceana) as the nominate subspecies, and the other subspecies listed as H.p. bjorndalei, H.p. majasi, and H.p. latefasciatus.
Photo of Heraclides aristodemus (aristodemus?) by Alejandro Sanchez, Puerto Rico.
Subspecies latefasciatus, also known as Heraclides aristodemus temenes, photographed by Alex Pemberton, Cuba, 2009.
Photo by Alex835, July, Cuba, 2020.
Subspecies majasi is found in the Bahamas, and bjorndalei in the Turks and Caicos Islands. The name majasi was coined to commemorate Mark J. Simon, since simoni was in use as a scientific name commemorating someone else, according to this paper identifying majasi as a distinct subspecies.
Heraclides aristodemus ponceana normally lives in what are called hammocks or hummocks--groves of tropical hardwood trees. It is not normally a pest on citrus fruit trees, though it can be confused with some of the other Heraclides butterflies that can become pests. Its favorite host tree is called torchwood. It can eat another native tree called wild lime (or cat-claw, or shake-hand, from its prickly bark), and will eat citrus leaves and fruit if offered them, but its instincts and habits lead it to live in dense groves of wild trees rather than well spaced plantings of citrus trees. Populations that have recovered since Hurricane Andrew have had access to torchwood.
In fact, the IUCN Data Book points out, torchwood and wild lime are relatively small trees that normally grow at the edges of groves of bigger trees. These trees, and the flowering bushes the butterflies like, appear after fires clear out space among the big trees. Probably these butterflies are adapted specifically to pollinate new growth after natural fires.
Though it is one of the "giant" swallowtail family, Schaus' Swallowtail is not all that gigantic. With an average wingspread of 3.5 inches, its size is in between the Tiger Swallowtail or Monarch, and Florida's native Giant Swallowtail, H. cresphontes; its coloring fits the same general pattern as cresphontes and it has been called cresphontinus. Some individual H. cresphontes' wingspread is over 5 inches. However, Swallowtails are variable, and big aristodemus and small cresphontes can look almost alike from a distance. Only in 1911 did William Schaus prove that Schaus' Swallowtail was a different species and not an undersized subspecies of cresphontes.
From a distance, it might even look like H. andraemon, which can live in the same habitat.
Florida's habit of spraying poison into the air, in a rather touching and pathetic attempt to control mosquitoes, is thought to have contributed to the near extinction of Schaus' Swallowtail. The butterflies are recovering on the Keys because the Keys are not normally sprayed.
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Several hundred Schaus's swallowtails could still be seen on regular basis on north Key Largo in 1972, but the species declined dramatically in 1973 when the local mosquito control district began sparying Dibrom and Baytex as mosquito insectices in the keys [1].
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See also:
Damage done to humans by spraying has never been honestly assessed, though here I stand to testify that it costs Florida tourists. More pleasant (and effective) ways to control mosquitoes involve natural predators, of which many, like birds, frogs, lizards, and dragonflies, have high tourist appeal. Some birds might also eat Schaus' Swallowtail caterpillars, but these big caterpillars make quite a meal for a bird and, if not highly toxic, presumably taste nasty to birds. Nevertheless, presumably to humor those who believe the poison spraying is controlling the mosquito populations--which I did not observe to be the case on Florida's mainland--spraying is still allowed on Key Largo, where resurgent Schaus' Swallowtail populations could expand again, if humans would get out of the way.
Although Schaus' Swallowtails pollinate pretty flowers and their comeback was an interesting science story, Floridians can be a bit jaded about their unique wildlife. People were not as enthusiastic as you might think they ought to have been about bringing back these butterflies, despite their commendable tendency to avoid citrus groves.
Climate change could still destroy Schaus' Swallowtail. Actually, major climate change, such as that which could beproduced by putting a big "data center" in Georgia or Florida, could easily destroy Florida.
A University of Florida teacher designed a virtual reality game to engage players with the idea of restoring Schaus' Swallowtail populations. So far, the game's popularity lags behind those of role models like Dungeons & Dragons or Pokemon Go, but give it time...
And the butterfly is featured on an "Endangered Pollinators" wall poster.
Buy it:
Chegg uses the five traditional subspecies (Heraclides aristodemus aristodemus, H.a. bjorndalei, H.a. majasi, H.a. ponceana, and H.a. temenes) in a lesson on constructing "dichotomous keys":
(Of these names, bjorndalei seems to commemorate Florida biologist Karen Bjorndal. Temenes probably refers to a legendary King Temenos in Greek literature; as words temenos and temenes referred to the sacred ground dedicated to a Greek god--sometimes a grove. Latefascia means "banded sides" or "striped sides.")
They've been photographed by Joel Sartore:
Colorful but lower-contrast female on the left. See the full-sized picture at:
Though Schaus' Swallowtails are big and beautiful, their human-avoidant tendencies may make them less charismatic than Tigers or Zebras. One blogger whined that Schaus' Swallowtails have "boring brown coloration."
Say what? Photo of a male Schaus' Swallowtail posted by Jneal at
Then again, males and females can look very much alike. (The one facing the top of the photo below is probably the female, going by her egg-loaded body shape.)
Photo by Pedrogenarorodriguez, Dominican Republic.
Bah! Only some of the females achieve subtle brown and gray coloration. Many of these butterflies are gaudy but people just don't get to know them in the up-close-and-personal way most of us in the Eastern States know Eastern Tiger Swallowtails. Schaus' Swallowtails don't seem to crave salt desperately enough to lick humans' arms.
Scientists have reared ponceana caterpillars in university laboratories and released them into these groves. Photos and video:
It is occasionally possible to see these butterflies at the Biscayne National Park. Attempting to "collect" them, or harming them in any way, would be a federal offense. Taking pictures is fine. You can also print off a copy of this brochure, or carry one, and report the sighting to the National Park Service. They would probably appreciate a copy of any photo you're able to snap, too.
However, you may notice that some of these links show people working with this species wearing masks and gloves and protective gear. That's not because of COVID. Schaus' Swallowtails live in places that are very friendly to mosquitoes...whose natural predators' populations have been decimated by continual spray poisoning.
Some flowers Schaus' Swallowtails pollinate:
https://www.fnps.org/plant/amyris-elemifera#gsc.tab=0 (primary host plant)
https://www.fnps.org/plant/zanthoxylum-fagara#gsc.tab=0 (also a host plant for the caterpillars)
Both torchwood and wild lime bear fruit that some humans consider edible, though not likely to compete with oranges, limes, or kumquats.
Eggs are laid separately, although caterpillars are sometimes said to be gregarious, and mother butterflies don't have to be particular about laying on the tenderest tips of the newest leaves.
Photo from Butterflies of America, by Alana Edwards, 2008. The leaf is torchwood.
The eggs hatch in a week or less. After that the caterpillars develop rather slowly for tropical butterflies, spending on average twelve days in each of their five skins.
Photo by Carlos2262, November, Dominican Republic.
More creatively ugly with each new skin, the older caterpillar retains the white collar and white tail segment. Photo by Jcs13, July, Florida.
The white tail segment flattens slightly and extends out at either side. Photo by Jcs13, same caterpillar.
Caterpillars can grow up to three inches long. Warty rather than bristly, they seem to be trying to look like the droppings of large sick birds. Possibly because their instincts have adapted to predation by ants, they put out their "stink horns" much more readily than some other Heraclides caterpillars. Their bite is not serious but, apparently on the premise that predators may not know this, they rear up and threaten to bite anything that touches them. For caterpillars they are large, and can chomp. And spit.
Photo by Isaacthelord, May, Florida.
Ants' predation on some species of caterpillars has been a "hot topic" recently. Though fire ant attacks are not known to have been a significant factor in the decline of Schaus' Swallowtail, they certainly aren't helping and a focus on ant-versus-caterpillar videos is likely to distract attention from the more serious problem of continual spray poisoning. Bigger, older caterpillars may be able to move away fast enough to survive. Smaller caterpillars are often surrounded and eaten. Bigger ones can shove ants away with their heads or discourage ants with their osmeteria. A study quantifying how well this works focused on ants' ability to attack Heraclides cresphontes caterpillars, but H. aristodemus caterpillars will round on a nuisance with their long white osmeteria popped out, looking like something no reasonable person the size of an ant would want to meet. Ants are not reasonable persons.The caterpillars probably have to shove the ants off the twigs where they meet.
Pupation can last for most of either one or two years. Most butterflies emerge to fly in the season after they were caterpillars; some wait through another season. Eclosion tends to follow rain, when new leaves grow. Years when this species has two generations tend to be wet years.
The chrysalis looks like a twig, complete with splinters and spots that suggest holes in the wood...and then one day it doesn't. It splits open and releases the butterfly within.
Normally Schaus' Swallowtails eclose in April or May and fly, if they live long enough, until mid-June. In some years a second generation fly in August and September.
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