How to Raise Eastern Swallowtail Butterflies at Home

Monarch butterflies get all the press, but the Eastern or Black Swallowtail, Papillio polyxenes, a large blue, black and gold and cream-specked beauty, flies in our neck of the world from April through November.   The Texas native provides lots of action in the garden when Monarchs are elsewhere.

Eastern Swallowtail

Eastern Swallowtail, recently hatched, resting in the grass. Llano River, Texas Hill Country. Photo by Monika Maeckle

We’ve been getting questions about raising Swallowtail butterflies in recent weeks. The wet June has made for a long season for dill, fennel, parsley and rue–the plants on which Swallowtail butterflies lay their eggs.  Below are some tips for raising them at home.

Eastern Swallowtail egg on Dill Weed

Eastern Swallowtail egg on Dill Weed.  Photo by Monika Maeckle

First, locate the eggs. The tiny yellow spheres perch prominently on the leaves of dill, fennel, parsley and rue. Check your plants frequently, as wasps, ladybugs, spiders and others will slurp up these protein pops as soon as they are spotted.  When you’re looking, you may notice some clear, dry, empty spheres, exactly the size of the eggs.  Those are empty egg shells already visited and consumed by predators.

Swallowtail egg

Close-up of Swallowtail egg on dill. Photo by Monika Maeckle

I usually snap off a piece of the plant with the eggs on them and take them inside to rest in a jar with the lid loosely closed.  Don’t worry about “smothering” the egg.   They’ll do fine until they hatch, usually within four days.

Once the little guys hatch, you’ll want to provide fresh air to prevent mold from growing on the host plant.  Bring in some sprigs of fresh plant and put them in the jar. I usually leave the eggs alone until the caterpillars are big enough to spot with a naked eye–generally two days.   You’ll see they’re tiny and hard to monitor, so again, leave them alone and just provide fresh air and fresh host plant until they grow bigger.

After a few days you’ll see a small black creature, perhaps 1/16th of an inch long.  If you look closely, you might notice a white or orange band in the middle of the body.  That’s your first instar, or stage, Swallowtail caterpillar.  They will eat quietly and consistently for several days before they morph to the next stage.   They’re rather nondescript and not yet as interesting as they will become.  Just wait.


First instar Eastern Swallowtail caterpillar on rue. Photo by Monika Maeckle

Up until this point, I may have had the Swallowtails in a jar or container with a loose lid or netting.  But now it starts to get interesting and I like to watch them eat and grow, although it can make a small mess.

Usually I gather fresh host plant and put it in a vase with newspaper underneath so I can observe the caterpillars literally grow before my eyes. The newspaper catches the frass, or caterpillar poop, that the caterpillars produce in volume.  The small, black odorless pellet-like droppings may seem gross, but they’re actually not.  Well, maybe for some people.  Generally I will set such a vase in a highly trafficked place in my home or office so I won’t miss the action in the course of any day. (Yes, I’ve been known to take caterpillars to work.)

Swallowtail bouquet

Bouquet of Swallowtail caterpillars in vase on fennel. Photo by Monika Maeckle

The caterpillars will continue to eat and morph for about 10 days.   What’s amazing is how different they look at each stage.   As they move through their instars, they completely transform, going from the unremarkable black cat with a white band to a prickly orange, white and black form, then to a black, green, yellow and white-striped creature often confused with Monarch caterpillars.

Throughout the process these boys eat voraciously–lots of fresh host plant.  In our hot Texas summers, I find dill expires early in the season but that Swallowtails will easily transition to the more abundant and heat-hardy rue or fennel.   At the ranch we have wild parsley and I have brought that home for feeding.  Once I bought organic fennel or parsley at the grocery store to feed a slew of Swallowtails when I had run out of fresh host.  The caterpillars didn’t seem to like it much (like us, they prefer FRESH greens) but they ate it in the later stages.

Swallowtail showing tubercles

Who goes there?!? Note the yellow “tubercles” which the Swallowtail shows off when bothered. Photo by Monika Maeckle

One of the most amusing aspects of raising Swallowtails is their interesting tentacles.  When they get to the last stages, they show distinctive yellow antennae when poked or bothered. This orange forked gland, called the osmeterium, shows itself when the butterfly perceives danger.  Upon the slightest nudge or threat, the yellow tentacles pop out of their head and emit a distinctive, sickly sweet odor. Kids are always impressed when you provoke the Swallowtail’s tentacles.

Swallowtail caterpillar sheds its skin. Photo by Monika Maeckle

Swallowtail sheds skin. Photo by Monika Maeckle

The caterpillars will continue to eat, shed their skins and morph to the next stage over about 10 days until they get to the fifth instar at which time they will cease eating and seek a quiet place to form their chrysalis. Swallowtails are famous for wandering far from the host plant and taking their time to emerge from the chrysalis at unpredictable times.  Monarch caterpillars are generally reliable in taking 10-14 days to eclose, or make the transition from chrysalis to butterfly.


Swallowtails, in contrast, can take a few weeks to many months to emerge.  Their unpredictability is also manifested in the varied color of the chrysalis that results from the final morphing.   Sometimes brown, sometimes green, you just never know what color a Swallowtail chrysalis will be.

Swallotwails wear chrysalis coats of many colors. Photo by Monika Maeckle

Swallowtails wear chrysalis coats of many colors. Photo by Monika Maeckle

Because Swallowtails can wander, it’s smart to contain them in a cage when they get large enough to bust their stripes and go chrysalis.  I use a net laundry hamper and simply put the vase inside.


The Swallowtail will bow its head and make a silk button and saddle before going chrysalis. Photo by Monika Maeckle

The Swallowtail, when ready, will stop eating.  He will bow his head in an upside down J-shape, and spin a silk button to attach itself by its head to a twig, branch or net siding.   He then makes a silk saddle to hold itself snugly in place for the time it takes to transform its DNA into a butterfly–again, an often unpredictable amount of time.   Some Swallowtails will overwinter to the next season, depending on the conditions present at the time of forming the chrysalis.

Newborn Swallowtail butterfly with sister chrysalis. Photo by Monika Maeckle

Newborn Swallowtail butterfly with sister chrysalis. Photo by Monika Maeckle

When the day finally comes, though, you will know because the chrysalis will turn dark, then clear. Thereafter, the Swallowtail will emerge when ready.

Give it a few hours to allow its wings to harden. When she starts beating them slowly, you know she’s ready for flight. Take her outside and send her on her way.

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149 thoughts on “How to Raise Eastern Swallowtail Butterflies at Home

      • Monica, we have 3 swallowtail crysalis on a branch. They’re in their terranium. Is it safe to take the terranium outside in sunlight for a few hours? We keep a wet sponge in for moisture and spray with water every other day. How much light do they need? Were in southern California. Thanks

        • It just depends on how hot it gets in the terrarium. It’s possible to “cook” the chrysalises. Good luck!

  1. Good information, Monica. I use perennial fennel for my black swallowtails because it grows very big and feeds a large number of caterpillars. I used to tell my students that in the early stages, they were like Oreo cookies. They could remember that when identifying swallowtails.

    • Yes, Ann, fennel just seems the best all-around host plant for Swallowtails, plus you can harvest the leaves and bulbs to eat. The flowers also give off a yummy pollen that fancy chefs are now using as an ingredient atop pasta and other delicacies. Thanks for writing.

  2. Fantastic Monika!!!!!!
    Thank you so much for making this whole issue more clear, more understandable! I unfortunately live in a major city, so unable to raise or see any myself here,
    But your sharing this all with all of us is so good, and very helpful, useful.
    Inspires and encourages me to continue with my work this fall on the Monarch Butterfly Life Cycle and Migration. My current version was not accepted, but I adamantly refuse to accept “failure” and fully intend to continue on with this project towards certificate (2nd one, after 1st accepted 2002 for Botanical Art and Illustration). Blessings to you for your own work and for your encouragement! Thank you!!!!

    • Thanks for the peace of mind. This is just the answer to my question I had never witnessed this before and was worried when I saw it happen.

  3. are there any Monarch butterfly organizations in the Berkeley area of California, that tag butterflies and report on their comings and going in the bay area?
    If I order stickers from you will they reflect my location here in California? with my zip code or some kind of i.d. where they came from?

    • Hi Beth,
      I don’t sell stickers and am not that familiar with California. The only Monarch butterflies that I’m aware of that get tagged are those east of the Rocky Mountains, since they are the ones that migrate to Mexico. You might check out the Pacific Grove Museum of Natural History, regarding California questions. Here’s a link: Good luck!

      • Thanks so much for the info.
        I really enjoy reading your articles. Very detailed and thorough.
        I made a slide show 2 years ago, of the first monarch caterpillars that came to my milkweed and ended up hanging all over my yard to my delight and astonishment.
        unfortunately it was a very wet and cold winter here in california and they all died on the vine, either from disease or just plain bad weather. I vowed to make sure that didn’t happen again.
        Last year I took them all inside and fed them as much fresh milkweed I could find and watched them develop from start to finish. 18 beauties flew off in the sun.
        This year I’ll keep even more, starting from the eggs.
        How can I send you the slideshow?

  4. I’m near Conroe, and my dill bolted in April/May. I cut it back, and it would immediately bolt again. Is there something I should have done to keep it growing?

    • The reason I switched to fennel is because dill and parsley bolt so quickly when the weather gets hot. It was always frustrating and buying fresh dill or parsley from the grocery stores didn’t always work. I have counted over 50 caterpillars on my fennel plants which grow over 8′ tall. As Monica pointed out, there are other advantages to fennel, too!

  5. Monika,
    I just planted a butterfly garden yesterday. I put in a couple pots of parsley. Was wanting to add something else for the swallowtails. But since its July, and I live outside of Austin in Hutto………the heat worries me. Wondering if I should wait and add more swallowtail host plants when the weather cools down? Or would you think I should try dill and fennel? I was looking into Rue, but with a husband with highly sensitive skin, and three kids in the house, I dont know if thats the best option. Advice?

    • Rue is probably the best for planting right now. But if you have a place under a tree that will get some light but not burn up, you could fennel. Dill just can’t take the heat. I’ve never had problems with rue on my skin–great plant in my book. Good luck!

      • Ok will look into seeing if I can locate it. Round rock gardens didn’t have any. My husband has extreme reactions to poison ivy and even ant bites…. Which is why I was nervous. The bed we planted everything in gets pretty much full sun.

  6. I would like to know if you have ever had to handle chrysalis’ and had them move on you? I literally just got bombarded with 40 caterpillars. The caterpillars literally ate the branch (feed fennel ,dill ,and parsley) right underneath the chrysalis and I have 2 now unattached to a branch. Today as I was moving the remaining 12 into cages, I hhad the 2 chrysalis in my hand. THEY SQUIRMED/WIGGLED. It has been at least 4 days since they became a chrysalis?????????

    • Yes, they move! I’ve had that happen, too and it can be unnerving. But why wouldn’t they when you stop to think about it? As I mentioned in the post, they could remain in chrysalis stage for months, so consider it reassuring that they are still alive. Thanks for writing.

      • I am a pro with monarchs but new to our Eastern Swallowtails here in Florida. What do I do with the chrysalis’? The two I have now, now unattached to a branch? If it can take them months, a year to come out, at what point do I know there is something wrong? Just keep it in a safe space and it either produces a butterfly by next year??????

      • Continuing on my question & your comment here on July 7th, it was very calming because today NOVEMBER 10th, FOUR MONTHS LATER & some of these chrysalis are beginning to emerge, a majority took about 6-8 weeks which I was advised about. Now, every other day I am having 1-2 emerge. I am left with 16, of the 16 only 3 look like they could emerge. My question and I apologize I cannot make this short and sweet Haha. My concern is the weather. I live in Florida. I DO NOT have any parsley, dill, or fennel plants left or available anywhere. I DO have orange Gatorade, bananas, oranges, apples, watermelon, honeydew, Asters, Butterfly bush, pentas, firespikes, milkweed, plumbago, salvias, shrimp plants, firebush, black eyed susan vine, and a purple passionvine. I am confident I can supply nectar to keep them alive BUT with this freezing weather fixing to slam the USA this week and next, how will they survive if set free??? Should I turn them out or keep them for as long as they’ll live?? Lastly, I currently have everybody underneath a screened porch (8ft by 20 ft). Do I move the chrysalis inside IF it hits a certain degree ( say like below 40 degrees) or leave them outside? I have a female who emerged Saturday morning around 8am. It was very windy this day(15-18mph per news) so I kept her on the porch. Yesterday it was windy, cold, and raining heavily..About 7pm I noticed her on the ground so I put her inside a cage and brought her inside the house to dry off and get warm. I supplied her with all the aforementioned and she perked up by midnight. I guess I am thinking along the lines of IF they do not stand a chance of survival WHY not keep them as long as they will live??????

        • Hi Melanie,

          I asked our butterfly breeder friends, and Edith Smith of Shady Oak Butterfly Farm says this: “They go into diapause when they go into chrysalis. They are already set. If they aren’t in diapause, you can’t put them into diapause by refrigerating them. I’m sorry.

          I think you just have to let nature take its course. If you hatch them and it’s freezing outside, you can feed them artificial nectar until a warmer day arrives. Good luck!

          • Thank You for ALWAYS answering quickly and for keeping this site rolling. I REALLY enjoy reading everybody’s questions and your responses. I never thought about Shady Oak. Probably due to the fact over the past year I have written them 3 times and NEVER received a reply. I found this site and will never go anywhere else. Happy Holiday’s …………Melanie

  7. Don’t know if I posted this,monarchs last year I raised and released six.
    This year I’ve seen them every day in my milkweed, an encouraging sign.
    I live in Kalamazoo Mi. and have seen more milkweed growing on the side of the road.
    I try to raise knowledge for the little winged ones’ but don’t know how successful I am.

  8. From my above post I am wondering how to treat any chrysalis that is unattached, not hanging by its silk noose per sey? Do I ape tem up, glue them up, lay them flat?????

  9. I found a swallowtail caterpillar on some dill a friend brought over. I put it in a container and fed it for about a week and a half. It’s now hanging on a branch by 2 silk threads as of yesterday. How long will it stay in that upside down J position before it starts to shed it’s skin? Is that the next stage? I see time lapse video but they don’t say how long each step takes. I am worried that maybe it’s dead?

    • It can take a day or two. Be patient. Think how much energy/concentration it must take to transform your body mass to a new life firm. Keep us posted.

  10. Re: swallowtail chrysalises
    It has been my experience that the butterflies that emerged from unattached chrysalises had deformed wings(some didn’t make it out of the chrysalises fully), so I began taping mine to branches with tiny strips of masking tape. It works for me. I have read of others using a drop of hot glue to attach them.

    • This is my first time fostering Swallowtails (I have experience w/ Monarchs and Gulf Fritillaries).

      I keep the cats in one of those huge collapsible hampers and most head for the top of the hamper and hang down, head nearest the top of the hamper, when they go into chrysalis

      However, thus far, all of the Swallowtails have positioned themselves sideways along the top edge. Is that typical? Are they going to be able to emerge correctly?

  11. I have raised several of the Eastern Swallowtails this year. Now I have some new caterpillars on my dill, and can’t find any info. on what kind they are. They are still in the small stage, but thicker bodies than the Eastern Swallowtails, and the center portion is orangish/reddish. Any help identifying them? They are very numerous!

  12. We have a Swallowtail that just emerged and it’s wings appear to be messed up so I do not believe I will be able to release it. What should I feed it?

  13. A few weeks ago I found some black swallowtail caterpillars on our parsley plant. I’ve been keeping them in an aquarium and just this morning two of them went into the pupate phase. I know that sometimes when they pupate this late in the year they will overwinter. I live really far south in Louisiana and am wondering because of our warm weather if they will not overwinter. Any thoughts? thanks.

    • IMpossible to say. They are highly unpredictable. I’ve heard from breeders that if you mist them, it helps speed it up, but this late in the year, I’m betting they will wait til the spring. Good luck! –MM

      • That is the issue I have been looking into. Living in Florida I didn’t know if my ST’s “overwintered” My last batch which turned into chrysalis around Aug 22-Aug 29th HAVE NOT emerged. Well, I lie, 2 have emerged. I have currently 14 not hatched. I DO keep misting them once a day but lately with all the rain they get wet, not directly but by the wind blowing, they are on my porch in cages, attached to tree limbs. I don’t know how to ”
        maintain” them “over winter”. I read somewhere if I really want to know if they are dead or alive, keep them in constant sun 13 hours a day. If you live where it snows etc, you have to use a light indoors??? IF I keep them as is on twigs etc, how do I manage them for 1 year???

  14. I found a swallowtail caterpillar while pulling my carrots in mid October. I live north of the 45th parallel, so it gets pretty chilly here in the early fall. I brought the cat inside and it ate a ton of the carrot leaves, and then proceeded to move to the J position. It looks like its getting ready to form a chrysalis, however its taking extremely long to do so, I’m thinking its been about a week since spinning the silk. I did move the caterpillar into a cooler area, in my unheated garage, mainly bc I want to overwinter the cat. should i be misting it? Is it just maybe the cold that is making it take so long to go to the chrysalis stage? should i bring it in to the house… I have heard they wont ememge in the winter anyways and I could just mist it every week or so… so many questions! Thanks!

  15. I have several black swallowtail caterpillars that have turned into crysalises. The last ones formed their crysalises last week, and I moved them all into a container in an unheated building. However, two of them are dark, and their wings are showing through, and when I looked at them this afternoon, when the temps were about 70, they were wiggling like they wanted to come out. This next week is going to be really cold, with highs in the 40’s. If they come out, and I let them go, there is no way that they could survive. I considered putting the two or them into the fridge all winter just to be sure that they stay cool enough, but I don’t want them to be ready to emerge and then kill them by getting them too cold at the wrong time. Assuming that they don’t hatch tonight or tomorrow, does the fridge sound like a good plan? Is their a point in their crysalis stage that it is too late for them to go into diapause?

      • Just an update, the two chrysalises hatched today. When my students and I went to check on them, one was sitting on a branch with its wings hardened. It was about 45 degrees in the room. While the student to whom it belonged was holding the stick, it began to release liquid on him. The second chrysalis was wiggling a lot, so we brought it into the classroom. We did not see the second butterfly emerging from the chrysalis, but we did see it minutes later, and the children got to watch as its wings unfolded. Now, it looks like we’ll have to try to keep them inside until this cold snap is over and if they are still alive, then we can release them.

  16. In regards to comment above would also like to know what to do with my chrysalis. I have several that formed over OCt 18th weekend and I have them indoors. Should I be moving the containers to garage or something where it’s cool?

  17. I just came across your lovely site. It looks like I will be fostering a cat or two this year. The one I brought in today was a first instar, found on a new rue plant. It preferred the parsley when offered both, tho. We’re having a bit of a heat wave and dry spell in Southern Ohio for about the past 7-10 days, which is not at all typical for September around here

  18. This summer one Swallowtail chrysalis fell of a stick I had put in the dill plant for the caterpillar to attach itself too. I used dental floss, wrapped a single loop around the chrysalis and then attached it to the stick it fell off of. After about a week or a little more it hatched and was a very beautiful black swallowtail butterfly. I got the dental floss idea from an other site where this same discussion was occurring and it worked. The butterfly had perfectly formed wings. Hope this helps someone.

  19. Using dental floss to attach chrysalises to a sturdy twig is directed to help Melanie Chesser. I made a loop and it looked just like the silk they make to attach themselves to something worked.

  20. I recently started growing fennel in my garden last year. This year I have Swallowtail larva galore. This past week I discovered at least 20 caterpillars in my garden. I’ve collected 11 in different instar stages. I’m keeping them in a large glass enclosure with a netted top. I have lots of fennel and more in my garden to bring in to feed them. Am I harming them by bringing them inside this late in the year. The temperature outside has been 72-75F during the day and 58F at night. I don’t want to hurt them, only want to observe them. Will a temperature change of a constant 72F (in the night time as well hurt them?) Any help you can provide would be appreciated.

  21. Pingback: Children’s Vegetable Garden (CVG): Week 4 (March 12, 2016) | Bexar County Youth Gardens Blog

  22. So I live in MI. I had lots of parsley growing on my porch garden. Which means lots of Swallowtails (caterpillars). Fun watching them eat away at the parsley, then cocooning. Long and short I brought one in first week of Nov. because the weather was getting winter like in MI. I kept it in an aquarium from Nov 1-2015 to April 11-2016. April 11th the butterfly appeared. Now I do not know what to do. He want to go and I want to let him go. The only problem is it unseasonable cold here in MI. Down to the teens at night and I fear he would not have a chance if I were to let him go. I plan on waiting a couple of days until the weather breaks and we get some 70 degree highs and 40’s for the lows. Any suggestions? Will waiting a couple days be alright?

  23. My two BST emerged today, the first (female) has taken flight the second is still drying its wings. I kept them over the winter as I did last year when I had two that emerged.
    Happy Day

  24. This was very helpful, now I rescued an injured swallowtail and it has been doing better since I brought it inside. I really don’t know what to give it to eat, I gave it some sugar water and Flowers loved it (my 6 year old daughter named it Flowers) any advice would be helpful, thanks.

  25. Thank you for the insight. This is our first year raising swallowtails. Found the caterpillars while weeding my dill. We have successfully raised seven to the chrysalis stage and now are waiting for the butterflies. Hopefully they will be gone in time for our monarchs to use the habitat. You were right about wandering. Loved watching every stage but had a few moments where we had to play Indiana Jones and find the missing friends as they explored the porch.

  26. Hi Monica!
    I discovered three swallowtails on my fennel last week and decided to cover the plant with a pop up hamper in hopes of keeping predators away. Once they grew big enough, I moved them to my indoor parsley plant and overnight two of the three formed their chrysalis and look to be doing great… but the third one seems to be stuck in pre pupation. He has his harness in place and has shrunk up and turned darker but I truly do not notice any movement. It has been three days like this. Is he still alive? I have been searching for clues as to what I should do with him (just wait and watch or separate him.) I did touch him gently and he seems soft but again, I am not sure if he is a late bloomer or if he just did not make it. Any ideas?

    • Hmm. Hard to say. I would separate him and wait a few more days. If he doesn’t make the complete chrysalis, then best to freeze and dispose of him. Nature is cruel. Good Luck. MM

    • I had one like that too, he died in assume during the initial transformation process. It was sad to see but I have 9 others that made it to chrysalis and one now went dark and is now turning clear. Very excited to see the butterfly!

  27. Thanks for your website to! Mine kept being eaten by wasps even when I clipped off the flowers as suggested on another site. I now have a netted pot and 9 in chrysalis with one more little one on cuttings in a vase in the house as the others ate every inch of what was in the pot. There were more but they ate each other (something I didn’t know) because some didn’t like the cuttings I was putting in to replace the decimated fennel.

  28. I’m in Louisiana and just this year I planted some fennel to eat …I ad only planted 6 seeds in March so they were all still babies when I noticed the wilting on some stocks . Upon further inspection I noticed little black and white worms and a few days later the worms were gone and I seen the caterpillar in all its glory 21 caterpillar on 6 baby fennel . They like celery as well which I had right next to the fennel they are not touching the carrot greens or the parsley and I just noticed they will eat the fennel stalks as well not just the fine green fuzz

  29. I raised a few Swallowtails this year on my back porch because for several years, they haven’t been able to survive in the yard. Bird and insects were getting them.
    So this year I brought inside the bronze fennel that they had laid their eggs on. I learned that they must be sprayed lightly with water in order to grow and survive. I almost lost them before I found that out. It rains in nature settings, right?
    I also lost a few from the wandering that they do when about to pupate. Some of them never could find a place and seemed to give up.

    I hope to try this again next year with the help of more knowledge.

  30. About the method of cutting fennel branches and putting them in a vase: I am afraid if I do it this way, my fennel will run out before my caterpillars are done. Panic! Any thoughts on this?

    • What I do to vastly extend milkweed may be applicable, at least to some extent, to other plants. I remove from plants only small amounts to sustain caterpillars for a short time, repeating several times throughout the day. Green seed pods, flower stems, green parts of yellowing leaves, portions of leafless stalks. I keep caterpillars separately by size, and feed them accordingly, so that big caterpillars do not eat the little leaves that little caterpillars must have.
      Likewise, tips of big leaves to littles, coarser remainders to bigs.

  31. What I do to vastly extend milkweed may be applicable, at least to some extent, to other plants. I remove from plants only small amounts to sustain caterpillars for a short time, repeating several times throughout the day. Green seed pods, flower stems, green parts of yellowing leaves, portions of leafless stalks. I keep caterpillars separately by size, and feed them accordingly, so that big caterpillars do not eat the little leaves that little caterpillars must have.
    Likewise, tips of big leaves to littles, coarser remainders to bigs.

  32. Thank you for the reply. At what point do you transfer the caterpillars to your plants? When they are egg, newly hatched; or adult caterpillars? I see more eggs on my outside fennels and I’m not sure if I should break off the leaves now or wait and see if they hatch before an insect or bird gets them. I’d like to chance it and wait til they hatch and need to eat or I will waste my fennel. I may just put a fine mesh screen over the bush and see if that protects enough.

    • I raise caterpillars in captivity both because predation is rampant (chrysales likewise are targets), and to manage their eating when supply is of concern.

      You can collect eggs by removing them from plants. Or by taking them on bits of plant material on which they rest.

      Fine mesh can reduce exposure to predators that do not find or make a way inside. For caterpillars, mesh should be supported by a framework that maintains as much gap as possible, which reduces overall amount of caterpillar time on the mesh where predators do sting and bite them from the outside.

  33. I bought organic parsley for the ones that are growing outside because they ate everything in the big pot the were laid in. They are dying now! Others are not eating. What is happening?

  34. To give more detail on my dying caterpillars, they are turning black. They were laid by the butterfly about 5 or 6 days ago. One that died and turned black was a very large caterpillar 🙁 Are they starving on the organic parsley? Is it poisoning them? We’ve put out some parsley still in little pots also from the store, not sure if it’s organic, but not sure they are taking to that either.

  35. I hope somebody smarter than me on the subject can help with answers for this. When I noticed my caterpillars not eating, I sprayed a fine mist of water on the whole plant because I know that in the wild they get dew in the morning and rain now and then. It did seem to get them eating again.

    Sorry about the caterpillars, it doesn’t sound too good for the ones that have turned black.
    BTW maybe you should order some small Bronze fennel plants for next spring and be sure they have that to eat. It’s their favorite. I have 2 large fennel bushes and just bought 4 more small ones. Good luck.

    • Thank you. We usually do have enough parsley and fennel to feed them until they cocoon, but this year we didn’t. I did spray some water over them this afternoon because I read in one of the comments that could burn up if it’s too hot. We are in Georgia, very hot. Also covered them some with a sheet for a little while and will do it again in the middle of the day. Thanks for the advice! Ordering a lot of fennel bushes is a good idea.

  36. Help! I put out the buffet and they came (spangled fritillary and others on the coneflowers, not just one but 4 swallowtail caterpillars and a couple of the tiny ones on the fennel–the monarchs seem to be ignoring the milkweed and one plant’s not so hot). But now all but the tiniest are MIA. Did they escape? Could they, over the mulch? I’m so hoping some (expletive deleted) thing hasn’t made a buffet of them, in turn. Should I put some grass clippings or take out some of the mulch? I’ve already had a tough time trying to convince a longtime gardener friend that they _aren’t_ tomato hornworms (my pics, are, admittedly, not great & my descriptions not a whole lot better.). Now this? Please help, thanks.

  37. For about 5 years now I have been planting a large planter box with parsley to attract the Eastern Swallowtails. It all started by accident because I used to plant the parsley for me. I always would get about 11 to 15, and have gotten to experience all of the various stages, from egg to new butterfly. The parsley would begin to get sparse, but it has always held out. I’ve had over 25 this year, and the parsley is all gone. I know they will die, but I don’t know what to do. There is no dill or fennel or rue. I have tried buying parsley at the store (last year) and they would not touch it. It’s probably too late now, but I just wondered if there was anything I could try.

  38. I am glad we found your posting. We live in Delaware and have been trying to do this outdoors for two years with little luck. We planted parsley and waited until we saw the little black caterpillars. Then enclose the area with a metal mesh to keep out he Jays and Bluebirds. However we found some of the caterpillars were disappearing, We forgot about Wrens they are small enough to get through the mesh. $26.00 dollars later we installed 1/4 inch screening. This should do it for now. But I think we will be going to try bringing them indoors.
    Thank’s and our butterflies thank you.

    • Mocking birds are also a problem here in South Carolina. But I found that when I tried to cover my fennel with mesh, insects were still crawling inside and eating the tiny eggs and baby caterpillars. So there’s nothing else to do except bring them into my screened porch. This summer I had pretty good luck and learned a lot for future endeavors.

  39. Hi
    I hope you can help me. I have a batch,9 black swallow tail instar on my parsley.
    We had 3 before and one made it to maturity,1 a bird got and one has turned black.( not sure there)
    Any way how can I make it easier for the instars get to a good spot to go t the chrysalis stage?
    My wife and I are finding this process fascinating and what to see more butterfly’s. Whats great is how accidental it all was I had no idea about how the BS likes parsley.
    I can send a photo of how the garden is arraigned if that helps with your suggestions.
    I look forward to hearing from you.

  40. We are used to swallowtail catapillars on our parsley. Six cats on one plant this Summer. After the parsley was stripped of leaves we put a bunch of store bought parsley in a vase. Cats did not seem hungary and by the next morning they all looked half dead. I moved the cats to our last garden parsley plant and all but one recovered. My guess is that the store bought parsley had been sprayed with dypel or something similar.

  41. I just found my 1st 3 swallowtail caterpillars today. They are either 4 or 5th instar. I brought them inside and put them in a container with sticks & food. Is there anything else I need to do? I have a butterfly garden and have had lots of monarchs, so I was pleasantly surprised to see them.

      • Hi Monika
        Its late in August and i have a 4th batch of instars. 11 or 12. I love watching them grow and transform its amazing.
        Here is the question I have a new guest in my small garden a Praying Mantis. Should i worry the PM will eat thenew instars?
        So far the head count hasn’t changed and the PM seems very content on the pepper plant.
        Look forward to hearing from you.
        PS is there enough time here in the east for these instars to become butterflys?

  42. Hi I live in Ontario and am raising what butterflies I find. Including both black and giant swallowtails. I also raised and released 25 painted ladies they are the easiest to raise. right now I have 5 black swallowtails in the crystalis stage. One fell off the zipper portion of the butterfly cage and is laying on the paper towel at the bottom. it had not yet hardened when it fell. I will try to attach it to a stick. The giant swallowtails are very interesting they really do look like bird poop when they are in the catipllar stage. I raised 2 successfully in my cage and left three others on the hop tree and observed them everyday. they were almost in their last istar when they disappeared. I am not sure if they were eaten or they crawled to a less exposed place. It is sad I have seen no monarchs this year in my butterfly garden. I used to raise them when I found them as eggs. I wonder if the eastern migration of monarchs into Canada is in a steep decline as the number of monarchs has decreased every year for the last 4 years.

    • It never is necessary to re-attach chrysales.
      They can be lain on anything soft,
      nearly touching a tilted stick or
      a hanging strip of cloth.
      Emerged butterflies immediately climb when they are not already hanging.

      • I had one I kept laying on a piece of paper towel in an aquarium for the whole winter. From Oct-April. To be honest I was not expecting much. But I thought I would give it a try. Sure enough I came home from work one April day and there he was , a black swallowtail had emerged. Took him to our local park and away he went, no worse for wear.

  43. This website is amazing. After 30 years of growing parsley in a plastic pot on my New York City highrise terrace without anything unusual happening, this week I saw eleven black swallowtail caterpillars happily chewing. When I came home from the store this morning with some cut organic parsley for the ‘pillers who had pretty much demolished my plant, the population had been reduced to three in the pot, one dead in the pot, and three wanderers on the paved flooring looking for a host plant for their chrysalis stage. I do not intend to help further in any way, but it’s been illuminating to read what you all do.

  44. I brought a black swallowtail caterpillar inside and he harnessed himself to a stick in the usual formation, but I just saw something really strange happen. What looks like a tiny larvae-ish green caterpillar just broke out of one of the legs of the hanging caterpillar and is now crawling around the inside of my enclosure. It’s tiny, but not at all what I expected (I expected the chrysalis). Any idea what happened?

    • Whoa, that’s a new one. Not sure what to tell you there. I’ve heard of eggs laid by tachinid flies, which then hatch, maggot style. Hmmm.

      • After doing some searching, I think that’s what happened (EW!). I think I’m going to build a “caterpillar cage” (a screened wood box) to set over my plants outside when I find eggs and caterpillars and hopefully that will help cut back on the predators we have here and still let my kids and I watch the process. Thank you so much for all the information on this site! It is so helpful!!!!!

        • Be careful of the screen size too fine and you will block the sun and your herbs will not grow. Too large and small birds and rodents can get in. I use a 1/4 plastic mesh that I wrap around some stakes and close at the top, I also place extra wooden stakes for the chrysalis. When I see caterpillars then open the topwhen a butterfly emerges.

  45. Help! It’s mid October, and I just found 10 cats on my organic parsley. It’s starting to get cold here in CT, and I don’t know if I am better off letting nature takes its course or if I should try bringing them in to my 4 seasons porch in an enclosure. With their irregular and unpredictable emerging from the chrysalis, I don’t want them to emerge just before the weather gets miserable, nor do I want to disrupt their normal patterns. Not that I have a choice as to when they emerge. I’m concerned that if they pupate and emerge during the winter months, how do I keep them alive until it’s safe to release them?
    But with the plight of butterflies today, I would like to aid however I can.
    It appears that at least one is in its final instar stage and will be pupating soon. Please let me know what you think I should do! I have so many birds that I am amazed the ‘pillars made it this long. So if it would be helpful to them, I would like to act quickly. If it’s not likely to help, I will just be an observer and not interfere.
    Thanks in advance for your advice.

  46. I have three swallowtails in a container, all different instars. One of them has formed its chrysalis already but it hadn’t even reached its last instar! Is this normal?

  47. Hello and thank you for this wonderful website! I live in NJ and brought in five eastern black swallowtail caterpillars. Four formed chrysalis’ about three or four weeks ago and one is still eating rue…I was surprised to find a butterfly this evening! I am not sure what to do now…did I make a mistake by not putting their enclosure in a colder climate so they could overwinter? I was actually waiting on the last one to pupate so held off. I am going to give the butterfly some nectar plant cuttings tonight but am considering releasing it tomorrow (10/28). Any advice appreciated! Thank you!

  48. Captive adults’ first interest is to be in their natural environment; they may or may not ever eat in captivity. Free adults’ first interest is to mate, and they normally do not eat for at least a day.

    I do not assume that cut plants retain good nectar. When I want to make food avaiIable to captives, I net them in with a living plant (or branch of it).

    • Generally, the live ones still are flexible and can move a bit. I wouldn’t discard one that seems completely stiff, but generally if they have no flexibility they are dead. That said, they can overwinter for many months, so don’t give up too soon. Good luck!

  49. I purchased some un-stratified milkweed seeds and I would like to know if there is a way to speed them up so I can plant them this spring. Otherwise should I just go ahead and reorder stratified seeds? Would the freezer help?

  50. I really need some advice and help with this. This year I cannot raise swallowtails on my screened porch so I bought one of those hamper/butterfly habitats instead. I had 2 nice big caterpillars in it and just about 24 hours after they went into chrysalis they turned dark and died. Is it possible that there is a chemical in the mesh of the habitat that is causing this? I am going to wash it good and try again. Do you wash your hampers when they are new before using them? Please help.

    • About the butterfly habitat: I seriously doubt there were parasites in the enclosed sun room that I put the hamper in. It is a part of my home and I don’t even open the windows. Thanks.

  51. > Posted by Pauline Lane
    > “milkweed seeds… to speed them up”

    Yes, soak them until they do not float.
    Takes one day if they are held down
    (e.g. by fine mesh);
    otherwise nearly forever.

  52. > Posted by Pauline Lane
    > “doubt there were parasites in the enclosed sun room”

    They reside inside and/or on the caterpillars.

  53. > Posted by Pauline Lane
    > “bring them in next time in the egg phase”

    Good thinking (for many parasites, at least).
    That leaves predators. And pathogens.
    Pathogens can be on the eggs.

    > “washing this hamper”

    Did you know that commercial breeders
    wash the eggs?

    • “That leaves predators. And pathogens.
      Pathogens can be on the eggs.”
      No predators in my sun room but lots outside. That’s the reason I bring them in.

      “Did you know that commercial breeders
      wash the eggs?”
      Ack! Can’t imagine washing something that small!

  54. My URL text is being removed here,
    so, you copy the partial :
    and add the .jpg at the end of it.

  55. Very nice and helpful article. I enjoyed it very much.
    Today I found dozen of caterpillars in my garden on dill and fennel plants. I assume they are Canadian Tiger Swallowtail. Will watch them every day.
    Thank you for sharing your experience.

  56. I put water droplets on my pupa and he came out with wrinkled wings and can’t fly. Was it because I over watered him? Please reply asap I loved this pupa with every fiber of my being. He means the world to me.

  57. Not long ago, I wrote that some hatchlings died in a butterfly habitat that I bought. I asked if anybody else had had that happen and I washed the habitat thoroughly afterwards. Since then I have had another hatchling die in it and last week I collected a bunch of eggs and very carefully put them inside the habitat with lots of bronze fennel.

    The next day I found more eggs and didn’t have room for them in the habitat so I set them up on a table with no enclosure.

    Today I find that these healthy eggs in the habitat have all turned black and the ones outside the habitat are now hatchlings. What else could be the cause of this except for a problem with the habitat?

    This habitat was one of those laundry hampers and I am thinking about purchasing a real butterfly habitat from a reliable source. I am just losing too many nice butterflies and it’s heart breaking. I have to save the ones that are okay but eventually they will have to be contained before they start roaming around to go to the chrysalis stage. Please give me your thoughts and suggestions on this. Thank you.

    • Oh, I have good news! I believe the eggs are okay! I see tiny babies on the fennel that must have hatched from those black eggs. Then I found this which I didn’t know:

      Black Swallowtail eggs are round and yellow, turning darker as they near hatching

      And this:
      When the eggs are close to hatching they will turn to a darker color. The dark color is the actual caterpillar growing inside
      But I did order another habitat from Shady Oak Farm and if all these little guys make it I will need 2 habitats to keep them all safe from roaming.
      Thank you so much for replying. I love visiting Edith’s website.

  58. Thank you, Monica! I was looking for just this information and you answered ALL my questions! We (and our parsley!) are proud to be host and hostess to a new generation of Eastern Black Butterflies!

  59. I need some advice if possible – a black swallowtail hatched on Friday (two days ago) and he still hasn’t flown away. I have been moving him between the various butterfly plants I have (lantana, sweeetvalyssum, monarda, butterfly bush, lavendar), and have provided him with diluted sugar water (1 tsp sugar to 1/2 cup water), provided watermelon and its juice, mashed banana and STILL – more than 48 hours later – he hasn’t flown away. Is there anything else I can do??

    • The only other thing to do is to toss it high.
      Cup it in hand, underhand pitch it
      with full force nearly straight upwards.
      It will flutter, either feebly or better than that.
      If the former, then you will know that it is
      completely incapable.

      If the latter, then it may fly to the nearest thing
      (tree leaves, roof, low bush, whatever),
      or to something several meters farther.
      It may stay there for longer than
      you care to continue watching,
      or make a few flights to nearby objects.
      Often they soon flutter to the ground;
      I do not know why they choose
      that hazardous place.

      A strong, long flight? I neither expect it nor
      rule it out.

      • Well, it seems he’s 100% incapable – he came pretty much straight back down. So how do I care for this poor little guy? Is there anything I can do for him?

  60. The humane options are
    – to euthenize
    – to feed, in isolation
    (inhumane if it never drinks).

    The broader concern
    is to prevent the spread of
    whatever is affecting it.

    [Fourth submission of this reply.
    Post it, dammit.
    This site certainly is quirky.]

    • I think the problem was that he went into chrysalis *in* the parsley, and there may not have been enough space for him to “hang” his wings (even though they *look* perfectly fine). I will continue to feed him. Thank you all!

  61. What spices do you like to use with the butterflies when they are finished? You mentioned dill and parsley, as options. And what way do you like to prepare them? Thanks, I enjoyed the informative website.

  62. We just had a swallowtail emerge from its chrysalis either over night or this morning. How long can we go without feeding it before we let it go? We are both at work and are hoping that if we wait until tonight it won’t be too long without food.

  63. So I currently have two butterdly habitats … one with 18 having made it to chrysalis stage and 2 more to go … probably 20 more in the other habitat that are in various instar stages (a couple even went into chrysalis there as well). All of these came from eggs that hatched on my (large barrel of) potted parsley. Needless to say they have been DECIMATING my remaining parsley – not that I mind 😊. Its been fascinating watching them go through all their stages and I can’t wait for the butterflies to emerge!

    The other day, hubby and I found about 20 more newly laid eggs on the parsley again. This time, I gently plucked off all the leaves with eggs and put them in a open tupperware container covered with a layer of cheesecloth and brought them in. My question is, (1) do I need to mist those eggs or just leave them alone and (2) when hatching seems iminent, is that a good time to put fresh parsley in with them even if its a day or so early (FYI, I keep the parsley in floral tubes to keep them fresher longer)?

  64. That’s great, good for you.

    (1) do I need to mist those eggs

    Mold is the risk, because to mist the
    eggs would be to mist also
    the leaves on which they rest. .
    IF low humidity, then immerse-soak
    and squeeze-dry the cloth. .
    Alternativel is moist napkin pieces
    inside, only at sides.

    (2) fresh parsley

    A purely practical matter.of
    the hatchlings’ having something edible.

  65. We’ve had an Anise Swallowtail caterpillar that has attached with its silk buttons and it hanging in the upside down J shape for 36 hours now, but no chrysalis. How long can we expect this pre-transitional stage to last? I think s/he’s still alive…

  66. I’m in Rhode Island. Winters can be nasty. Will eggs winter over? Should I leave my fennel and milkweed standing so the eggs can hatch in the Spring? I want a tidy garden, but I want butterflies more!

    • The eggs will hatch, grow and pupate well before winter. It really doesn’t take long. I found some “just about ready to pupate” caterpillars on my parsley in late October! (in CT). I took them in, fed them until they pupated and kept the Chrysalises in my unheated garage until spring. No care whatsoever except to keep them safe. Had beautiful swallowtails in mid-May.

  67. I really appreciate the information you gave here. I took in five caterpillars, and all five hung and made their chrysalis. I was getting worried because it was late August already when I found them, and winters get nasty in PA. Is there any care that they need inside to keep them hydrated inside or warm in the winter if they do overwinter?? There was a new black swallowtail outside this weekend on my butterfly bushes, so I worried whether my inside guys were okay and should have been out already. Your post and the comments and answers above did give me some relief, but I also still worry if they will make it. I guess that’s the mom in me. THANKS!

  68. Great information, thank you!!!

    We brought one inside during its last stages of caterpillar and it escaped its “cage” & is in the upside down “j” position at the top of our curtain!!! Do you think this will be an ok location for it if we can keep it undisturbed?

  69. Very vulnerable to omnipresent tiny insects that you never notice.
    Most do not fly, and I make chrysales less vulerable by
    suspending them where insects are less likely discover them,
    e.g. a horizontal string between tall far apart lamp stands.

  70. I have some black swallowtails that just chrysalis-ed yesterday but the 2nd one is not attached on the bottom and facing upward and outward like the other guys. He is still attached at the top but not the bottom. He is almost black. Is he dead? I actually caught some of his metamorphosis which was so cool but I did see his bottom become detached when he started moving violently. It was amazing to watch but if he’s dead I will feel bad. I didn’t cause this to happen, it happened on it’s own but also to point out, he still has the bottom remnants of his butt on the end of his pupa and the other 2 don’t so I’m wondering if that’s what caused him to fall off? If anyone can let me know if he’s still alive I’d appreciate it so much.

  71. I brought in my parsley plane the day before the first frost, 3 days ago. It has 2 black swallowtail caterpillars on it. Today one ran away, I found him and put him back but he is now on the wood floor. Should I keep putting him on the plant? Will he die if I just take him out to anouther plant?

  72. I have 4 black swallowtail chrysallis from late Sept 2017. They have been on my porch all winter. This morning 2 emerged I believe because it is unusually warm this Feb (in the 60 – 70s daytime). I brought them in and made a butterfly hone with popup mesh laundry baskets. It’s too early to release them since we may still get cold weather until April. What do I do???? I put some gatorade in a dish. What else do I do to keep them alive?? Help!

    • I’ve had 2 emerge myself over the last two weeks – VERY odd … its way too early! Unfortunatley both of mine were going to be non-fliers either way ao I just gave them some nectar and made their short little lives as comfortable as possible. Instill have 6 more chrysalises too – hoping they’ll stay put till better weather!

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