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spiroan

Swallowtail Egg question

spiroan
9 years ago

Hi everyone,

I had a black swallowtail lay at least seven eggs on three different dill plants two days ago. The last time a swallowtail laid eggs (I only saw two), I waited until they hatched, cut the stem they were on, and then brought them inside to a screened-in cage with a wood bottom to raise them. They are in chrysalis stage now. However, I am curious as to whether it might be a good idea to go ahead and cut the stems and bring the eggs in to wait until they hatch. Thoughts? Should I bring them in or just wait until they hatch and then bring them in?

Comments (20)

  • MissSherry
    9 years ago

    Congrats on the black swallowtail chrysalides! I haven't even seen one in over a year!

    I usually wait until the eggs hatch to bring them in to raise myself. Since dill doesn't hold up well in water, by the time the eggs hatch, the dill will already be drooping, not good. If you get egg eating predators, though, you might want to bring them all in now. So, it just depends on your situation.

    Sherry

  • Leafhead
    9 years ago

    I agree. Usually enough hatch that you can have up to 30 cats at a time on Mammoth Dill or on Fennel. A Swallowtail ELF will return about two or three times and lay on average 8-10 eggs per visit. Eggs generally hatch in 5-7 days in warm times, and they turn dark the day before hatching. These dark eggs I collect.
    I keep newly collected eggs separate from hatchlings to prevent cannibalism. I'll generally raise about 3 batches of 10 or so.

    John

  • spiroan
    Original Author
    9 years ago

    Thank you both!

    Come to think of it, I thought I saw some more eggs last night (I just assumed I had missed them before). Do the females return several times during the day or a few days in a row to lay eggs?

    John, on the subject of cannibalism, will the larger caterpillars eat the smaller ones? Or will they only eat eggs?

    Sherry, I will try to get some pictures of the chrysalides for you. They have been in them for about a week and a half now. So, I'm hoping they will eclose soon. Is there any way to know if they are still alive in there? Or is it just a waiting game? Also, what would you consider to be egg eating predators?

  • MissSherry
    9 years ago

    I don't know what those predators might be, because, knock on wood, I've never had them here. I do remember, however, that others on this forum have posted about their butterfly eggs disappearing, thinking that some predator got them. I don't think it's too common, though, it's just mostly the caterpillars that get eaten by wasps, predatory stink bugs, and certain spiders.

    It's mostly a waiting game with your chrysalides, but I don't remember it taking long for spring raised black swallowtails to emerge. With the green ones, you can easily see when the butterfly is about to emerge - with the brown ones, I've never been able to see any tell tale coloring that predicts it.

    The larger caterpillars, in the process of eating the host plant, will sometimes devour a small caterpillar. I don't think this is purposeful, the little one is just on the wrong leaf at the wrong time! Like John, I separate my caterpillars out according to size.

    Sherry

  • spiroan
    Original Author
    9 years ago

    Thanks again, Sherry! My chrysalides are brown, so it looks like I'll just be waiting for a while. Maybe I'll paint the inside of the cage green, so they'll be green next time. :)

  • runmede
    9 years ago

    I've never had a BST eat an egg or smaller caterpillar. I always think of BSTs being friendly to their roommates. A friend of mine watched one totally avoid the egg.

    It usually takes about 3 weeks for BSTs to emerge from their chrysalis.

  • mrmath_gw
    9 years ago

    Miss Sherry,

    Here in south Florida, ants are the worst egg-predators that we have. They will eat almost any kind of butterfly egg. I am glad that you do not have this problem.

  • MissSherry
    9 years ago

    Ugh - ants! I've seen ants eat a spicebush swallowtail chrysalis, but never seen them get an egg.

    Like I said, for those who have egg predators, it would be good to bring the eggs in.

    Sherry

  • spiroan
    Original Author
    9 years ago

    I've been watching. The eggs are still on the plants, so that gives me hope. Hoping they hatch in the next couple of days. Tomorrow evening will be five days, so we should be getting relatively close. I do have some fire ants in the garden, but the numbers are dwindling rapidly. I've been pouring hot water on them every chance I get, and it is killing a lot of ants. It has killed a couple of plants, but it has definitely killed WAY more ants than plants.

  • spiroan
    Original Author
    9 years ago

    YEAH! I got home today, and found three small BST cats on my dill. So, I brought them in. In addition, I brought three other eggs in since I figured they were close to hatching. This morning, I had 5 BST cats in the cage and just 1 egg! And I saw two other BST cats on the dill outside this morning. Unfortunately, I didn't have time to bring them inside before work. So, I'm hoping they are there this afternoon when I get home. Either way, I'm SUPER excited!

  • MissSherry
    9 years ago

    Woo hoo!! Congrats, congrats!

    Sherry

  • Leafhead
    9 years ago

    Congrats, Congrats indeed :)
    I have 4 eggs on my Fennel as well, due to hatch anytime after Saturday. I'll bring them in when they turn dark...

    John

  • spiroan
    Original Author
    9 years ago

    John,

    Do you have bronze fennel, or is it another kind?

  • Leafhead
    9 years ago

    I have Florence Fennel and a lot of Bronze seedlings, as well as some Florence seedlings. The three that have eggs are about 8" high now and the rest of the Florence is still in the cotyledon stage. My Bronze seedlings all have three leaves now.
    I like the Florence Fennel because it grows so big and fast.

    John

  • docmom_gw
    9 years ago

    John, does fennel spread by rhizomes as well as seedlings. I found a new sprout near my old plant, but it may be coming up from the original roots. I know my sister has more seedling than she knows what to do with. I'm hoping to expand my fennel planting, but I didn't get any seedlings that I can see, yet.

    Martha

  • Leafhead
    9 years ago

    Martha,
    As far as I know, Fennel starts by seed only. There are no rhizomes involved. What you are seeing is a plant returning from the roots. I am just starting to see seedlings pop up, so you shouldn't be too far behind. As long as your Fennel goes to seed at the end of the year, you'll have lots of volunteers in the Spring.

    John

  • spiroan
    Original Author
    9 years ago

    Thanks, John. Mine is bronze fennel. It is relatively high now, but our growing seasons are quite a bit different. I got home yesterday, and had more eggs on my dill. For some reason, they are passing on both the fennel and the rue I have in my garden. Both have plenty of plant to support caterpillars, but the butterflies don't seem to care. I even watched a BST lay three eggs on a VERY small dill seedling while completely avoiding the fennel and rue. Maybe they just prefer different plants in different areas, and maybe even different times of the year. Worst case scenario, though, at least I have some fennel and rue to feed the caterpillars in my cage.

  • Leafhead
    9 years ago

    Interesting. Caterpillars do prefer different things in different regions. Your dill must be in a perfect climate and provides maximum nutrition, hence the preference over Rue and Fennel.
    My two experiences with Fennel were extremely positive, both in South Fla and in Wisconsin.

    John

  • Debra Vessels
    9 years ago

    I had parsley, fennel and dill last year, and the BST only laid eggs on the Dill. So I planted plenty this year, skipped the fennel, and planted two parsley. If I think I need more I can still find some. Maybe the dill is a regional favorite for our Texas BST. I haven't found any Rue locally, so I haven't planted that, maybe next year.
    Congrats on all of your cats and eggs also.

  • Leafhead
    9 years ago

    Thanx, Debra,
    And good luck with your Dill. Hope you get lots of BST ELFs :)

    John

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