Pipevine Swallowtail Butterflies and Their Host, Dutchman’s Pipevine

Late one afternoon a pair of dazzling creatures caught my eye as I walked toward my car in the parking lot at Bowman’s Hill Wildflower Preserve.  They were Pipevine Swallowtail butterflies, a male and a female, flitting about in the neighborhood of a very large Dutchman’s Pipevine (Aristolochia macrophylla), the plant that gives them their name.

As I watched, the female occasionally landed on the Dutchman’s Pipevine, staying in one spot for a few moments, with her lower abdomen curved slightly to touch the Pipevine leaves or stems.  She was laying eggs!  In the photo below, two roundish orange eggs are visible on the stem of the vine, next to her right front leg.  If you look carefully at the tip of her abdomen, you can see a spot of orange – she’s just about to lay another.

Pipevine Swallowtail Butterfly laying eggs on Dutchman’s Pipevine

Some butterflies have evolved a survival strategy that enables their caterpillars to feed on a wide variety of plants, but others, like the Pipevine Swallowtail, have chosen to specialize on a small number of plants that give them a particular advantage.  To protect itself from being eaten, Dutchman’s Pipevine has evolved with chemicals that are at minimum distasteful to those who would eat it, and if a sufficient amount is ingested, they are toxic.  Pipevine Swallowtail caterpillars are among the few creatures who are able to process these chemicals without harm to themselves, then store them in their bodies in such a way that they are toxic to their potential predators.  This chemical protection even survives metamorphosis and extends to the adult butterfly.  It is so effective that other butterflies mimic the appearance of the Pipevine Swallowtail, since this is often enough to warn off predators.

Pipevine Swallowtails lay their eggs in small clusters of usually less than twenty, often on young leaves or stems of Pipevine plants, members of the genus Aristolochia.  In the mid-Atlantic, the only species that Pipevine Swallowtail caterpillars can eat are Dutchman’s Pipevine and Virginia Snakeroot.  In the southwestern part of its range, there are other native Pipevine species that this butterfly uses as its caterpillar food plants.

Pipevine Swallowtail Eggs on Dutchman’s Pipevine

Soon after they hatch, the young caterpillars have a reddish spiny appearance. They tend to feed together in groups.

Young Pipevine Swallowtail Caterpillars

Older caterpillars usually feed alone, and their appearance changes, with colors appropriate for Halloween – black with orange trim.

Pipevine Swallowtail Caterpillar on Dutchman’s Pipevine

Adult butterflies feed on a variety of plants for their nectar, and may also seek out minerals at puddles.  They don’t feed on the flowers of the Pipevines, however, because they are not a good anatomical match for feeding or pollination.

Dutchman’s Pipevine is a deciduous vine with large heart-shaped leaves, but it is named for the shape of its flowers, which have a curved tubular shape ending in a flair with an opening in the center to allow pollinators to enter and search for a nectar reward.  The graceful Pipevine Swallowtail is too large to enter, and even its proboscis can’t extend enough to navigate the long curved tube to reach the flower’s food offerings.

Dutchman’s Pipevine Flower in bloom

So how are the Pipevine flowers pollinated?  Small flies and gnats are attracted to the open throat of the flower by an aroma they can detect, and by the color pattern, both directing them forward down the tube.  As the insects enter, they are prevented from reversing course by hairs that line the flower’s throat, forcing the insect forward, a little like the metal spikes at parking lot entrances that will puncture your tires if you back up.  When the insect reaches the nectar source, it meets the sticky stigma of the female flower parts, depositing pollen brought in on its body from another Pipevine flower.  The plant detains the insect until the flower has been fertilized, offering it shelter and nectar, sort of like a little insect bed and breakfast.  The female flower parts wither, and the male parts mature, releasing pollen for the insect to pick up on its body.  The flower tube and its hairs relax enough for the insect to escape the way it entered, taking the pollen to the next flower it visits, ensuring the continuation of both the Dutchman’s Pipevine and the Pipevine Swallowtail species.

Dutchmans Pipevine on fence at Bowman’s Hill Wildflower Preserve

15 thoughts on “Pipevine Swallowtail Butterflies and Their Host, Dutchman’s Pipevine

  1. I would love to plant a Dutchman’s Pipevine in my yard. Are they wild or is there a place I can buy it. Another great post! Thanks.

    • Hi Bobbie,

      Dutchman’s Pipevine is both – it’s wild and can be purchased for use in a cultivated garden setting. It’s a plant that is native to much of the eastern United States, and can be found growing in natural areas, usually in a woodland setting. It likes part shade, and moist, well-drained soil.

      You can look for it at your local garden center, but when you shop, make sure you’re getting the plant you want by asking for it by its scientific name, Aristolochia macrophylla,in addition to its common name, Dutchman’s Pipevine. The reason for this is that many plants may be sold under the same common name, but only one plant is know by the Latin name. This is always a safe practice.

      If you can’t find it at a garden center, try a nursery that specializes in native plants. An internet search for ‘native plant nursey’ will usually get some results. If you’re in the neighborhood, you could try Bowman’s Hill Wildflower Preserve, just south of New Hope, Pennsylvania. The Native Plant Society of New Jersey provides this list of nurseries that may have native plants:

      http://www.npsnj.org/plant_lists/Nurseries%20with%20Natives.pdf
      Using native plants in your garden will help ensure that you have an interesting variety of visitors, like the beautiful Pipevine Swallowtail. Native plants have evolved together with the insects, birds and other critters who depend on them for food and shelter.

      Hope that helps!

      Mary Anne

  2. Thanks for sharing all the info about the pipevine swallowtail butterfly and the dutchmans pipevine. I felt like I was attending a nature webinar loaded with interesting facts. The photos were gorgeous! Did you ever think of offering a nature photography class? Thanks for sharing. I might consider growing this vine just to attract the butterflies.

  3. After 3 years of growing a pipevine, i found a large 3rd inter cat and transferred it into my wire covered cage along with its food. The next day I was checking on it and noted 4 microscopic – almost invisible cats- just out of the eggs? Never noticed them before.. Must have been on the same pipevine leaf i brought in that the large pipevine was on..They’ve tripled in size in a day. One was stuck on the side of the plastic containers I use to hold the leaves for food – I drill a very small hole and put the stems in the water..being careful to make sure the holes in the plastic lids have absolutely no openings in the water, they drown easily. Can hardly wait till see what tomorrow brings. Last year i had zero sightings of swallowtails or monarchs and could not figure that out.. have sighted one monarch this year… pgs

  4. I have a trellace covered with this vine and recently has gotten a sickness. It is drying out and I am afraid of losing the plant. The leaves have these brown egg like spots all over them and I’m trying to figure out how to treat it! Can anyone please help! I don’t want it to die!

  5. Pingback: Haiku: Pipevine Swallowtail Butterfly Chrysalis – heartclosetblog

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