Yellow Admirals: how do you tell the sex?

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    I have been keeping the last of my Yellow Admiral butterflies back for breeding, instead of releasing them as I usually do. To start with, I had a bit of trouble getting them to nectar, but they all seem to have got the hang of it now. I have had nectar plants (a small hebe and alyssum, both in pots), and a whole lot of cut flowers such as daisies, philadelphus, dandelions as well as gatorade in a dish with a plastic pot-scouring-pad, and dishes of cut fruit and mashed bananas. They never took to the fruit, and eventually they went off, so I removed them. Four of them seem to prefer the Gatorade, and one insists on only ‘natural’ nectaring. I can tell that one apart because it has also fluttered its wings to shreds. Anyway, the next hurdle was pairing. I expected them to pair after a couple of days. This didn’t happen, at least not while I was observing them…but I suppose could have occurred while I was at work. So I thought I would have to try to hand-pair them. I had learned how to do this with Monarchs, but of course Monarchs are sexually dimorphic, and much bigger. And I think the Monarch males might be a whole lot more aggressive about it than our more gentlemanly Admirals. Anyway, then I realised I couldn’t tell the sexes apart, so I wasn’t sure that the reason I had no pairing wasn’t simply that I had no pairs! (i.e. there were only five butterflies, so they could easily be all the same sex). Anyway, tonight I came back to see one couple pairing. Joy!

    How long will I have to wait for eggs to be laid?

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    Thanks so much for that Norm.
    #3 The answer is just what I was looking for, as I didn’t know the process.

    All the other answers have been really helpful, and the idea of keeping a file is a great idea.
    I have been noting a lot of things on my butterfly calendar, and have been referring to it often.



    Anna,Pepetuna,Terry and all, my answers here are from my own experience and references from Lepidopteran biology. I respect Terry’s comments and if some points differ it must be remembered that butterflies are a huge and diverse subject covering many families and species.
    1. This possibly depends on the number of ova a particular species produces. I kept a sole captive bred female Red Admiral after pairing and releasing the male. During the 2 weeks I kept her in the butterfly house 164 eggs were deposited, after which I figures she had earned her freedom and released her.
    2. Both sexes are capable of multiple pairings, possibly varying with species, conditions etc.
    3. After mating, but before fertilization, the female stores the males sperm sac in her corpus bursa, situated in the abdomen. When the female passes the egg through her corpus bursa the egg then becomes fertilized, and proceeds down the oviduct to be deposited on the hostplant. So the egg is fertilized as it is laid. The process may be difficult to carry out with a dead butterfly.
    4. May well depend on a host of factors such as captive or wild, male or female, temperature, season etc.
    5. Pepetuna has given an answer there.

    Lepidoptera study, as mentioned above, is a hugely diverse subject with a long learning curve of assimilating relevant information, facts and experience by breeding and experimenting. I keep a file and any facts and information sourced is entered into the file. Also keep notes on breeding by recording dates, times, any unusual events, which all together makes an invaluable reference file.
    Together we can increase our knowledge of NZ butterflies and their habits, as little is documented.



    Thanks very much for that. The more I learn, the more I find I want to learn more….if that makes any sense!?

    In my Gazebo/butterfly flight, I give the grass a squirt of water every day, just to keep it a bit moist for the Admirals, and also have dried leaves/scrub hanging in places so the Admirals can hide away if they want. Their wings still get fairly tatty after a while though.

    Thanks for that Pepetuna, I’ll try and track that down from the library.



    Hi Anna. To answer your last question: “Are there any science type websites that you know of that explain the process of ovipositing etc? (I have googled, but haven’t found any so far)” the process of oviposition is extremely complex, and if you Google you will only find the simplest explanations (that oviposition strategies vary between species, that choice of plants is determined by temperature, age of the host plant, how many plants are growing in the area, how many eggs the species normally lay on one plant…etc) You will get better answers to specific questions about a particular species from the people who rear them, like Terry and Norm for Admirals, and Nigel Venters or Edith Smith for Monarchs (I can give you their contact details if you email me).
    If you want a scientific overview, you are best to start with a review article like:
    Renwick, J. & Chew, F. (1994) Oviposition behavior in lepidoptera. Annual Review of Entomology v39:pp377-400.
    If you are a student, you can get access to the whole article via Web of Science, a database most of the Universities will have. If you’re not, try interloaning it through your local library.
    I should say (before you’re all thinking :What does she know?) that I’m not a lepidopterist, but I am a reference librarian: helping students find information is what I do.



    Hi Anna

    Norm will correct me if I have answered any of your questions wrong but from my research and observations.

    1. Both myself and another lepidopterist here in the UK observed that females are more fertile if they are paired often, as after a while the fertility drops from the first pairing and a fresh pairing with any male will allow the female to lay more fertile eggs.

    2. The one male will pair with all of the females, but he will need to be well fed with a good source of quality nectar.

    3. It is possible to force a few of the eggs from the dead female but this would be a very delicate procedure and not something I have ever tried.

    4. Yellow Admirals can put up with very dry and hot conditions, where as the Red Admirals (Gonerilla) I have found prefer a semi-shaded and more humid condition. As for nectar it depends on the strength. I do not use ready made nectar such as this gatorade stuff mentioned here but find the following sufficient. 1 pint of water to 8 teaspoons of caster sugar and 2 teaspoons of honey and a pinch of sea salt. Have had no problems with this mix with any of the nymphalidae or in particular the Vannesids (Admirals). And they even enjoy it when it ferments in hot weather, although I change it regularly to prevent this. Our Red Admiral (vanessa atalanta) gets drunk on rotten fruit in the autumn and I have more than once walked up to one and picked it up because it has been for use of a better word intoxicated.

    5. Good question I will have to come back to you on this one unless of course Norm already has the answer.



    Norm…I have lots of questions re: breeding Admirals, so hopefully you (or anyone else)can help?

    1) Once they have paired, does that female need to be paired again, or is she fertile for all the future eggs she oviposits?

    2) If theres only one male, and lots of females as you mentioned above, I wonder approx how many he can pair with?

    3) If theres a fat, previously paired female that dies, can the eggs be saved…(if its eggs making her fat?)

    $) Anyone know how much moisture/nectar is needed per day per Admiral? I wonder if they would use about the same amount as a bee?

    6) Are there any science type websites that you know of that explain the process of ovipositing etc? (I have googled, but haven’t found any so far)



    Great to hear you have eggs Pepetuna. Now its fingers crossed they are fertile ones…I have had females happily laying eggs only to find they don’t develop into caterpillars! You should see a bit of colour after 5 or 6 days.
    (I find its the Red Admirals that are more likely to have some infertile ones here.)
    I can send up more Yellow Admiral caterpillars if you find they are infertile.



    Thanks Anna. I went and had a closer look at the two nettle plants and sure enough, there are tiny eggs all over them. Much smaller than Monarch eggs. Just as well I have heaps of other nettle plants ready to go!

    Yes, I too find that they feed better late afternoon/early evening. I just put some more Gatorade into the dish with the plastic pot scourer in it, and they all nectar happily. Except the one that didn’t like Gatorade…and sad to say, it died.

    So released 4 of the 5 butterflies today after a good feed…they flew off happily into the sunshine. Thanks both Anna and Norm for your help.



    Pepetuna…the eggs are really tiny and clearish, so may be hard to spot. I learnt what they looked like by watching a female laying, then looking with a hand lens. The Red Admiral eggs are a little bit different to the Yellow ones.

    PS/ Also with Admirals in an enclosure, I make sure I mist it daily with water so they don’t get too dry…and mine all get a feed at dusk, to make sure they don’t go to bed hungry or thirsty! Spoilt eh?
    I have a couple of guinea pigs as lawn mowers in the gazebo to keep the grass at a manageable level…they do a great job.



    Oh, I should have thought of that! (Marking the paired couple).
    Thanks for that idea, Anna. Norm, I’m afraid the joy is premature…I did have a pairing, but can’t see any eggs yet. There are 2 nettle plants in there. Hoping she might get around to it today, tomorrow…soon anyway.



    Pepetuna, I have found it pretty befuddling trying to determine the sex of Admirals….esp if they are new butterflies. The other day there was a pairing, so I put a tiny black dot on their wings with a felt pen, so I could identify them later….but I still find it hard.



    Hi Pepetuna,
    We are spoilt with Monarchs and the obvious difference between male and female, while the Admirals show no sexual dimorphism at all. The standard system is examining abdomen size, with female being short and stout and the male being longer and more slender. This sounds simple but is often confused by a newly emerged males body size looking much like a female until it has ‘settled down’ or a male gorged on nectar, and unless one has both sexes to compare it does need a little practice and experience to gauge the difference. Or you can examine the genitals with a strong magnifying glass but this also needs experience.

    You are lucky to have a pair with only five butterflies as I have had 14 females emerge before a male finally ecloded. Butterflies normally pair during late afternoon, and if you have admirals emerging it pays to wait until a pairing has been achieved before releasing any.

    One often reads or hears of butterflies feeding on fruit but this mainly pertains to tropical or semi-tropical species where fermenting fruit on the ground is common, not really applicable to our New Zealand species. While they may sup on cut watermelon or other fruit it is foreign to their normal diet and can indicate the need for a source of moisture to prevent dessication, particularly when kept in an enclosure.

    With any numbers of contained butterflies it pays to have a source of artificial nectar as well as flowers as their intake of nectar can be quite high.

    Pleased to hear you have eggs, and depending on temperatures you should have larvae emerging in 8 – 10 days.



    Should have read the Factsheet more carefuly – I see now that ovipositing should occur within 24 hours.

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