Friday, July 10, 2009

Why hasn't my swallowtail emerged from its chrysalis?

Eastern Black Swallowtail Butterfly Chrysalis Pupa Cocoon
"Why hasn't my swallowtail butterfly emerged from its chrysalis (pupa - cocoon)?

This question is difficult to answer as it is asked. First, there are a few questions that need to be answered.
1. What species of butterfly?
2. How long has it been since it pupated?
3. Where has it been held since it pupated? (Indoors, garage, etc)
4. What type of humidity is near the chrysalis? (living plant, spraying it with water, etc)
5. The chrysalis is in how many hours of light?
6. Does the segmented abdomen move it you apply GENTLE pressure to the side of the abdomen?
7. If so, does the abdomen move back after you apply pressure?
8. Does the chrysalis feel like it weighs normal or is it super light?
9. Is there a tiny hole in the chrysalis? Have you seen small 'gnats' near it?

So ... why these questions? Let's take them one by one.

1. Generally, it helps us understand more about the butterfly if we know which species we are discussing.

2. If it pupated last week, it could simply be taking a while. Swallowtails are not known for their emergence to be as predictable as other species of butterflies. If it has been a month or more, we need to look further into the situation.

3. If it has been in an air conditioned or heated building or in an area without humidity, it may have dehydrated. If it is in direct sun or a in a bright window, it may become LITERALLY cooked due to the heat from direct sun, especially through glass. (See next answer.)

4. Assuming it is where it could become dehydrated, we need to know if a source of humidity is near the chrysalis. If you has a living plant with the chrysalis, the plant will probably add the needed humidity to the air. If you are spraying it with water two times a day, it should not dehydrate. If a wet sponge or other source of evaporating water is with the chrysalis, it should not be dehydrated.

5. If a chrysalis is in less than 14 hours of light, it may still be in diapause. Swallowtail butterflies spend the winter as a chrysalis and can stay a chrysalis for 9 months and more if the day length where the chrysalis is located isn't 14 hours or more.

DO NOT put it in direct sun. It should be in bright light but NEVER direct sun. It can be kept on a table NEAR a window IF the table receives 14 hours or more light. Artificial light is adequate. Our farm's swallowtail pupae are never placed in sunlight but are kept in a lab with ONLY fluorescent lighting. NOTE: diapause is determined by the length of daylight or night, NOT by temperature.

6. A dead swallowtail chrysalis' abdomen will be frozen in place and cannot be moved when GENTLE pressure is applied at the jointed part of the chrysalis. If it moves, the tissue between the segments should be light in color. (See #9)

7. If it does move, it should move back to it's normal position after pressure is released. (See #9)

8. If the chrysalis is dehydrated, it will feel as light as a feather or cotton ball. The butterfly inside will be totally dehydrated.

9. Chalcid wasps are parasitoids. They lay eggs inside a soft chrysalis and eat the chrysalis from the inside out. If a chrysalis is infected with chalcid wasps that have not yet emerged, the tissue between the abdominal segments will lose the normal light color and will become dark.

Mature chalcid wasps eat a tiny hole in the chrysalis and emerge. A tiny hole in a chrysalis is a sign that the maturing butterfly inside was food for maturing chalcid wasps and they have emerged.

If a chrysalis is infected with chalcid wasps, it is NOT a butterfly chrysalis any longer. It is a shell for chalcid wasp larvae or pupae.

Side note: A butterfly does not make a cocoon. Some moths make cocoons. Learn more about cocoons here.

If the above doesn't help with your question about your chrysalis, please feel free to write to with your questions about your chrysalis or any other butterfly question.


  1. It's been about a month that the Monarch has been in "his" cocoon. It is changing colors rapidly. (Located at the shaded corner of garage). It changes from the green, to creamy yellow, to black, back to creamy yellow. I've had plenty of cocoons, but this one is rare. How long will it take for this Monarch to hatch?

  2. This is so very helpful, thank you. I have had a Chrysalis (Giant Swallowtail) in a jar covered with cheesecloth for 19 days now. It will occasionally move, so I think it is fine, but I should probably start misting it, as it may be dry... I'll check when I get home. I've bumped the table by accident and it moves a bit, and I take that as a good sign..?

  3. One of our Black Swallowtail chrysalides has pretty obviously died. Could you tell me what may have happened? I have a theory that its not being able to detach the old skin, which clung tightly to the bottom of the pupa, was unsanitary. They all worked HARD to remove theirs, but this little one just didn't succeed.

    I took a few pictures before "burying" it in the bushes a few minutes ago. Could the photos be of any use to you?

    It weighed about nothing, compared to the others.

    It also turned black/brown, with dried-looking pale wing areas, as of today - it started out brown, tan and cream.

    And a deep depression developed weeks ago in the abdomen - looks like the 6th-7th segments.

    The other 3 are looking OK, near as I can see.
    Sharon Sivertsen, Grayslake, IL

    1. Sharon, it's been a while, but if you're still wondering... Some caterpillars simply don't succeed in the chrysalis-formation process. They aren't able to clear the skin off and get stuck. There was probably something wrong with the cat itself that caused it to form a bad chrysalis, not the attached skin that was the problem. Happens all the time. I've periodically been able to catch it in process and gently pull the rest of the skin off, but it almost never makes a difference. The cat is just faulty.

  4. My chrisalis moves when I gently press the abdomen, but it is not changing from its original color. It has been 1 week, so far. It is a Black swallowtail.

  5. Hi, Edith. You helped us out last year with identifying some pulse here in Omaha, NE--thanks!The two black swallowtails that emerged both had deformed wings & couldn't fill them out. This year, we planted many favorite foods & 6 milkweed hybrids. All, including butterfly bushes, are in bloom, but there are few butterflies, and No swallowtail! Or monarchs. Are we expecting them too early? Our best, Norman

    1. I had an abundance of milkweed this year, and exactly zero monarchs to eat them :/ I didn't see a single butterfly this year. Did they eventually show up wherever you are?

    2. I had an abundance of milkweed this year, and exactly zero monarchs to eat them :/ I didn't see a single butterfly this year. Did they eventually show up wherever you are?

  6. We "rescued" a swallowtail caterpillar and placed it in an appropriate container. After a week of eating parsley feverishly it became enconsed in its chrysalis . But it's been weeks since. It only has about nine hours of indirect sunlight. But was unaware of spritzing with water. Do you think it's ok? So sad if it died:-(

  7. my giant swallowtail was born today but one side {wing}hasnt opened

  8. my giant swallowtail was born today but one side {wing}hasnt opened

  9. Many caterpillars on my parsley and fennel. will chrysalises be on those plants? if so I will leave them in the garden until spring. If not, where would they be?

  10. i have one chrysalise, it seem going to change today, it look dry but there a crack line from the back. im putting light on it while timelapse it.

  11. My little swallowtail butterfly has been in his coccon for 23 days. The other day I misted him and the cocoon started bouncing like a Mexican jumping bean. F
    Do you think there is any hope he might emerge?

  12. hi - i brought in 5 black swallowtail caterpillars that were feasting on my dill in my garden. It has been a delight to watch them! 3 have formed their Chrysalis and wow what a sight! But now i'm not sure - do i need to keep anything in the container with the Chrysalis'?? i see info about keeping moisture but will a living plant be fine in same container? Or should i spray water into the aquarium from time to time? I am not sure what i should do and any info on this would be super! Thanks you!

  13. oops - ok i found some info on this and see it's important to spray them twice a day! yikes! Thankfully they've been in an aquarium with live plants so hopefully there's been enough moisture for them these past couple of days.

  14. I've only found swallowtails by me, so that's what I've been raising - got milkweed... nothin' so far, ugh. Anyway, I just wanted to (very late in the conversation) mention my current experience with a black/brown chrysalis. Mine have so far anchored to sticks, but this guy decided to lock on to the top of the mesh cage... where there's black trim, on the edge. I haven't had many, so was sad to read a black one was likely dead - spritzed with water... nothing. Reached in to flex it and it wiggled so much I jumped! I find it fascinating how they'll try to camouflage themselves! I just wanted to mention it in case anyone experiences similar. It only changed over a few days ago, it's earlier sibling chrysalis is just starting to darken now, so I expect soon. They always seem to come out when I'm asleep, I'm really hoping to watch one come out, fingers crossed. Enjoy your nurturing!!

  15. My black yellowtail butterfly fell out of his harness. I didn't think it was going to make it but it is turning into a feudalism now. It fell so I put it on a leaf. WHAT DO I DO? Need help please. Thank you

  16. Hi Amy, came across your post today and had seen this posted about the same problem you are having, scroll down to the 2nd and 3rd answers, hope it helps!