Black Swallowtail Butterflies

Copyright 2013, Jim Long
No reproduction or reposting of this material is allowed without permission of the author.
Black swallowtail caterpillar, eating one leaf of fennel.

Black Swallowtail on Butterfly Weed (Asclepias tuberosa)
This is a re-posting of what I wrote about black swallowtail butterflies in 2010 and it's timely today because these colorful caterpillars are appearing in the garden this week.

Butterflies look so slow and docile, gently flitting about the garden. Just get our your camera and try to catch them in their daily duties of sipping nectar out of flowers; you'll quickly see they are shy, move fast and don't like being photographed.

I doubt their eyesight is so great they can see me, but maybe they can. I guess if you're an inch tall and a looming giant, 500 times bigger than you are and carrying a menacing black box with a big moving eye-lens, you might run, too.

Weak, tired and with much of her color worn down, she drank nectar for a day before laying eggs.

Maybe they simply sense a person following them in the garden. After all, their senses must be impeccable, or else they couldn't travel great distances. This Monarch butterfly, above, on the white flowered chives, showed up just as the chives were blooming. As you know, Monarchs spend their winter in South America and manage to navigate northward as the weather warms in spring. This one was worn to a frazzle, weak, but sipping nectar in order to regain her strength for laying eggs for another generation of Monarchs.

A Tiger Swallowtail, dishing up breakfast from dianthus in my edible flower garden.
Most people seem to like butterflies, but many of those same folks have no hesitation for stomping caterpillars. This time of year you'll notice what we always called "dill worms" when I was growing up.
The caterpillar of the Black Swallowtail Butterfly on a fennel leaf.
Black Swallowtail butterflies lay eggs on: fennel, dill, parsley and related plants. Those hatch into the caterpillar you see above. The caterpillar hangs around on one leaf and eats most of it, then pupates, building a little cocoon around itself and hanging there in a little hammock until it has grown. The cocoon splits and out comes the adult Black Swallowtail.
The majestic Black Swallowtail, newly hatched.
An older Black Swallowtail, on oregano.
The list of herbs that attract butterflies is long and extensive. A few you might want to plant if you wish to attract butterflies: Mint, oregano, butterfly weed, Mexican butterfly weed, rue, dill, fennel, parsley, sage, rosemary, thyme, lemon balm, roses, sweet marjoram, hyssop, chives, monarda, yarrow - the list really is quite long.
Monarch caterpillar, see how different they look from the Swallowtail caterpillar?
Monarch caterpillars, however, hang out, sip nectar and lay eggs on butterfly weed (Asclepias tuberosa) which is in bloom right at the time Monarchs are looking for food and home. In case you don't recognize butterfly weed, here's a picture, below. Note that lots of butterflies like the nectar from this plant but it's the Monarch that likes to hang its hat there.

Fritillary butterflies on butterfly weed.
Here in the Ozarks, the butterfly weed is a common roadside plant, starting its bloom around the end of May. This is an old-time medicinal plant, sometimes called, "pleurisy root" because of its use in treating that ailment.

So, if you see, "worms" in your herb plants, let them be, they turn into butterflies or moths and they're not going to ruin your plants. You'll be glad you left them alone when they turn into butterflies! And if you're going to photograph them, well, give yourself more time than you think you will need, they can run faster than you can.


Yvonne Jenkin said...

Thank you for a timely article. I am new to Missouri and I love the many types of butterlies that are here. I have been working on my butterfly garden and now have most of the plants you list. I had 3 monarch catapillars last year and I hope to see more this season.

Yvonne Jenkin said...

THank you for a timely article, Jim. As a new transplant to Missouri I have been enjoying the large number of butterflies here. I have planted most all of the recommended plants and I am looking forward to even more cattepillars this year.

Thank you

Donna said...

I'm confused... The Swallowtails laid their eggs and I found the worms at the end of summer. Do they produce twice a year? They cover my Herb o' Grace plants. Enjoyed the pictures, thanks.

Jim Long said...

Yes, Donna, the butterflies lay eggs all summer long, that way, if there's a late frost, they still have another hatching.

Anonymous said...

Nice article and pictures!