Ed. Note September 30, 2012: The following article was written for the September MWHA Newsletter, but due to spatial restrictions, it wound up on the cutting room floor. Since Swallowtail season is nearing an end, in the interest of notifying folks who might be interested, we are running the article on the website only.
Three Species of Swallowtails currently flying in Mount Washington
By Daniel Marlos
In honor of the new butterfly garden that the beautification committee is installing in Elyria Canyon Park, we want to feature a different butterfly in each of this year’s newsletters to draw attention to these superstars of the insect world. Three species of Swallowtails, large and colorful butterflies, are in flight right now, attracting attention as they glide gracefully through yards that have conditions they find attractive.
The Western Tiger Swallowtail, Papilio rutulus, is a large black and yellow striped butterfly, nearly five inches across, that sails about conspicuously attracting attention even from people who fail to notice other members of the insect world.
Another common swallowtail is the slightly smaller Anise Swallowtail, Papilio zelicaon, also a black and yellow species that has probably become more common due to the prevalence of wild fennel in vacant lots. The feathery looking plant is an introduced species that serves as a food plant for the young caterpillars. The female will also lay eggs on carrots, parsley and other related plants in the vegetable garden.
The newest addition to the swallowtail family in the Mount Washington area is the Giant Swallowtail, Papilio cresphontes, our largest local butterfly that was first reported in 1998 but is now rather well established. Colored brown and yellow with a distinctive pattern of spots that forms an X on the wings, the Giant Swallowtail is an impressive butterfly. Of the three species, the Giant Swallowtail appears latest in the season. All three species are flying in August this year. Giant Swallowtails are attracted to Lantana, Mexican Sunflower and Butterfly Bush as nectar sources.
Any gardener who wants to attract butterflies to the garden needs to provide a food source, and all three species of swallowtails eagerly take nectar from such cultivated plants as butterfly bush, milkweed, lantana, plumbago, zinnias, phlox, bouganvillea and other nectar producing flowers. Even more important to attracting butterflies is ensuring that there is a larval food source nearby. Tiger Swallowtails have caterpillars that feed upon the leaves of native sycamore and willow as well as some introduced ornamental plants like avocado.
The Anise Swallowtail’s caterpillars will feed on a variety of garden herb like carrots and parsley as well as the introduced wild fennel. The Giant Swallowtail increased its range from the eastern portion of the United States because its caterpillars have taken a liking to feeding on the leaves of cultivated citrus trees, especially orange trees, earning them the common name Orange Dogs. Orange Dogs are also well camouflaged as they resemble a large bird dropping to a predatory bird more than they resemble a tasty caterpillar. All three species of swallowtails have a unique defense mechanism. If disturbed, they produce a forked, normally hidden scent organ known as an osmeterium that produces an odor that some predators find offensive.
Keep an eye out for these large showy butterflies and encourage their caterpillars by cultivating plants that will sustain a healthy food supply for the larvae.