eastern tiger swallowtail, dark morph: dorsal view, closeup showing markings on hindwings
While researching butterflies I learned that there are six dark-winged swallowtail species in Maryland: the black, giant, palamedes, pipevine, spicebush, and dark morph eastern tiger.
eastern tiger swallowtail, dark morph: ventral view showing hindwing markings
The dark winged butterfly that I had been shooting on joe-pye weeds [see previous post] was a dark morph eastern tiger swallowtail (Papilio glaucus). The dark morphs are always females.
eastern tiger swallowtail, dark morph: ventral view showing body
Several characteristics distinguish dark morphs from other butterflies with dark wings, but the one that’s a dead giveaway is the lack of white spots on the body.
eastern tiger swallowtail, dark morph: ventral view showing white “dashes” on wings
Also note that the white marks on the trailing edge of the forewing are elongated: dashes rather than spots.
dorsal view
It wasn’t until the next day, while I was shooting yet another species of butterfly (subject of a future post), that I saw what I thought was a spicebush swallowtail (Papilio troilus). I didn’t even realize at the time that’s what it was, because I was so focused on the other one that I didn’t stop to think that this particular butterfly was actually resting on a spicebush.
ventral view
Note the round spots on the body, and also the fingertip-shaped bluish markings at the trailing edge of the hindwing. The lack of a lighter patch in front of those blue marks indicates that this is a female. SEE UPDATE BELOW.
Spicebush swallowtails range from eastern Texas north into the Midwest and southern New England, and south into Florida. Several species of plants host the caterpillars, most notably spicebush (Lindera benzoin). Adults feed on quite a few different plant species, including some exotics; among the native species are milkweeds, dogbanes, and thistles.
another dorsal view
I’m totally kicking myself for not hopping the fence that was in my way to get better pictures. I’ve checked my spicebushes several times each day since then, but haven’t seen another butterfly on them.
giant swallowtail
Here’s a giant swallowtail (Papilio cresphontes) that I photographed in the eastern panhandle of West Virginia a few years ago. I’ve never seen one of these around my house; they are found in most of Maryland, but are fairly rare.
pipevine swallowtail
I believe this last one to be a pipevine swallowtail (Battus philenor). The plants it’s on are Aristolochia fimbriata, white-veined Dutchman’s pipe, a South American species that’s growing in the Enid A. Haupt Garden next to the Freer Gallery of Art in Washington, DC. Aristolochia species are hosts for the pipevine swallowtail, and so the gardeners in the Haupt and the nearby Mary Livingston Ripley Garden have been growing them for several years now, in order to attract the butterflies. Smithsonian Gardens has some wonderful spaces around the Mall, but I’m digressing.
UPDATE 8/22/18: The second butterfly is NOT a spicebush swallowtail. I failed to see something obvious. Pictured is the almost-identical red-spotted purple (Limenitis arthemis).
I checked many resources for help understanding butterfly identification; particularly useful sites included
Elizabeth's Wildflower Blog 