This morning was nice and calm and I decided to wander around and see what I could find in the garden. Found a few large Atala caterpillars munching on my coontie out back. They're very hard to take a good photo of, because depth of field is such a problem. Coontie are low-growing plants, so it's difficult to maneuver a tripod into position, so the "traditional" digital answer to this problem (aligning and stacking multiple exposures taken with slightly different focus points) is much harder to achieve. So the best I've been able to do is hold as still as possible, try to align the axes of the lens with those of the subject, and hope for the best. Here's a passable image, probably the best I've managed despite having the photo op literally 15 feet from my back door whenever I feel like it:After I was done frustrating myself with this subject in the back yard, I wandered around to the font, where I found this lovely Gulf Fritillary butterfly resting on the Bahama Senna: Unlike the ones flying up high in the passionvine out back, this one was very still. I suspect it was freshly emerged and still drying its wings; they're not normally this quiescent in the bright morning sunlight. The native plant society might not think too much of my garden, but the native insects appear to enjoy it anyway!
The Giant Swallowtail (Papilio cresphontes) is not the largest butterfly in North America. That distinction goes to the Eastern Tiger Swallowtail, at least to the larger females of that species. P. cresphontes, though, is still "noteworthy for its size" (Cech & Tudor). It's also a butterfly that is rather camera shy, at least in my experience. (The only pictures of an adult Giant Swallowtail in my photo files date back to Fern Forest days, back in 2007 or 2008.) Their larvae, however, are considerably less camera shy, and over the years I've noticed (and even written about) the tiny little "bird dropping" caterpillars that were showing up on the wild lime (a good Florida native plant) over in the corner of the yard. (I had thought that it was an out-of-the-way corner but wild lime is such a phenomenal grower that it's starting to crowd out the rest of the plants over there, and with all the little thorns it carries, it does a fairly good job of getting all the space it wants!) And their eggs, if you can find them, are even less shy of the camera, although they're so small they're quite difficult to get a good photo of, at least before you purchase a decent macro lens. I like the one in the shot below because, even though it was taken with a "normal" lens, the egg has a nice pearlescent sheen to it: An interesting note about the host plant, Zanthoxylum fagarum: like many other plants in the citrus family (Rutaceae, or rues), it is chemically active. It produces the aromatic "essential oils" that, true to their description, carry the "essence" of the fruit with them. They are "volatiles" as well, which basically means that they are fragrant. Some of these plants in the citrus family also produce toxic chemicals, in this case furanocoumarins, that discourage herbivory. Unless, that is, the herbivore can sequester or detoxify these chemicals somehow. Famous examples of this ability to detoxify chemicals include the Monarch butterfly (which can detoxify the cardenolides in milkweeds) and the heliconians (Julia, Zebra, Gulf Fritillary) that are able to feed on passion vines by detoxifying the various substances found in those plants. These little guys start off life just about as small as you can imagine: Before growing up to be one of the largest butterflies on the continent. And the "orange dog," as the Giant Swallowtail caterpillar is named, is able to detoxify the furanocoumarins found in wild lime, and this presumably confers some survival advantages similar to that of the famous "poisonous" milkweed caterpillars like the Monarch. This chemical defense, combined with the spiny nature of the host plant and the relatively disgusting-looking camouflage it employs (not many birds, at least, are likely to try to eat something that looks like a bird dropping), allows it to pursue its life cycle relatively unmolested in my yard. I say relatively unmolested because, well, this sometimes happens: My guess is that spiders aren't too fazed by the "bird poop" disguise, and if this thomisid (crab spider) was any more fazed by the chemical slurry inside the caterpillar, I don't know about it. Anyway, this week at long last, I found a cooperative adult from these (or nearby) caterpillars, and can at last bring you a picture of a Giant Swallowtail from my own back yard. Since this butterfly was in a shady area on a sunny day, I also learned a thing or two about photography. Here is the first image, taken with my 10-year-old Nikon D70, which I've completely forgotten how to control. I couldn't get the flash to fire so I had to set it to "auto," and it opened my aperture all the way up to f/3.2: Look at how nice and bright green the background is, and how bright (some might say overexposed) the butterfly looks. It's not a bad picture, and I'd probably have stopped right here if it hadn't been for two things: (1) the butterfly was absolutely motionless, allowing me to approach to as close as my macro lens would let me get without batting an eyelash (not that butterflies have eyelashes, but...); and (2) the left forewing ("top" wing) was obscured by some of the foliage. Since I didn't want to muff the next shots, and the butterfly was absolutely unmoving, I ran back inside to get my much newer D7100, which I've been using for the last year and a half. With this camera I was able to manually control the aperture, stopping down to f/16 to increase the depth of field. (Which, based on these images, hardly seems worth having done.) Doing so, however, made the background much, much darker, rendering these photos taken in broad daylight (admittedly, in a shady location) into "night-time" images: Despite the pictures being taken with digital cameras that were manufactured a decade apart (which is about a century in film years), the images are fairly comparable, except for image size (6MP for the D70, 24MP for the D7100). (I have, of course, downsampled them severely for web use.) Throughout this whole photo shoot, the butterfly hardly moved at all. I was able to get within a foot or two of it and take photos to my heart's content as it remained motionless in its bower. Here's a head shot, showing the amazing compound eyes of this large butterfly; you can see the rolled-up proboscis sticking out down below as well: And, last but not least, on the final shot I was able to get the whole butterfly, whose left wing came out from behind the distracting leaves from the first couple of shots: Even this shot, though, isn't perfect. The pose isn't quite as classic, because that darned left forewing is now slightly elevated, disrupting the symmetry of its resting position. Shortly after I left to take pictures elsewhere in my rather small backyard, I looked back over to this corner and the butterfly was gone. PS—according to my butterfly bible (Cech & Tudor's Butterflies of the East Coast: An Observer's Guide), the caterpillars of this species are called orange dogs because their "faces" (anterior ends) resemble a dog's head. You make the call:
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: 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: 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!):
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.] References 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.