Happy Spring Equinox! Monarchs en route, and the Eastern Swallowtails are Back, too

The Winter Equinox occurs this Sunday, March 20, and heralds the beginning of butterfly season.   Monarch butterflies are en route from Mexico, with first sightings reported in Texas.   Also fluttering:  gorgeous Eastern Swallowtails, often seen but seldom celebrated.

Perfect Eastern Swallowtail

I’ve written before that Monarchs get all the glory while the less lauded Eastern Swallowtail, a Texas native and almost year-round resident, is treated like a lesser step-sister.   Yet these enormous, dramatic butterflies are easy to attract to your gardens with parsley, fennel, dill and rue–herbs that are easy-to-grow and can double as edible landscape.  In fact, eggs and a first instar caterpillar were spotted on my front yard dill weed just this week.

So why are Eastern Swallowtails so underappreciated?

Those who breed Swallowtails for fun or profit bemoan their unpredictability.   They roam away from the host plant when they’re ready to form their chrysalis,

Eastern Swallowtail egg on Dill Weed

making them difficult to track and enjoy.  They are famously unpredictable in their hatching schedules, eclosing at their own pace, making them tough to breed commercially.

“Swallowtails are very delicate,”  says Dale McClung, of the Florida Butterfly Farm and a member of the International Butterfly Breeders Association. “They are very susceptible to wing damage in flight houses and will lose their tails very quickly from repeated contact with the screening,” McClung says.  He adds that the Eastern Swallowtails’ unique pupae,

Swallowtail Chrysalis

Eastern Swallowtail Chrysalis

which hang at an angle with a saddle stitch, require extra space and effort to cultivate, package and ship for educational exhibits and other exposure opportunities.

Members of the IBBA are largely responsible for raising awareness of butterflies in recent years by supplying them by the thousands to butterfly exhibits at zoos and demonstration gardens, as well as those used in celebratory releases, educational outreach and research.  Challenges raising Swallowtails surely contribute to their lesser popularity, compared to the storied, migrating Monarch, which reproduces like clockwork.

“They are beautiful butterflies. I have raised several species of Swallowtails over the years. They are extra work and expense insofar as space and plant material, so many do not bother with them for releases, but some of us do, ” says McClung.

Swallowtails’ unpredictability can be charming.   When they hatch on their own schedule–sometimes weeks or maybe months after forming their lovely chrysalis–you may come home to a pleasant surprise like the perfect specimen pictured above, which had been overwintering in my office since last October and just decided to eclose this week.

Eastern Swallowtail Caterpillar First instar

Eastern Swallowtails’ charm is also magnified by a clever protectionist tactic:  they disguise themselves as bird droppings in the first instar stage, pictured above, to evade predators. Later, they turn into chubby black-green-and-white striped eating machines often mistaken for Monarchs.

For more on Swallowtails and their host plants, visit this previous post at the Butterfly Beat.

UPDATE:  Dale McClung of Florida Butterfly Farm adds via an email:

“Swallowtails are high flyers and need a large space to roam more naturally. . . . Many swallowtails, unlike monarchs and most other butterflies, do not “land” on flowers when feeding or laying eggs, they gently hover in place while holding position with their feet. Eastern blacks will land, but also will flutter in place as well. During the daylight hours, they are, therefore, in more or less constant motion only stopping when roosting for the night in the wild.”

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