Too many caterpillars/not enough swan plant

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  • #15081


    Hello all – getting lots of phone calls at this time of the year from people who have either (a) too many Monarch caterpillars, so much so that they’ve run out of plant, or (b) they’re telling me that they’re aren’t any Monarchs in the vicinity and that they would LOVE to see some eating their swan plants…

    This often happens in various communities – in one area there are many wasps kililng all the caterpillars, and somewhere else there are no predators/parasites so the Monarchs are thriving. It’s nature’s way of "controlling" the various species… when the food runs out only a few of the strongest will survive.

    The problem is that we humans "like" some species (Monarchs for instance) and "don’t like" others – perhaps you dislike ants, or wasps or whatever. Nature, however, doesn’t see it like that, Nature runs the world in a "boom or bust" way, there are always peaks and troughs as one species (plant or animal) goes from thriving or struggling.

    But that doesn’t help YOU with YOUR problem… What I suggest is that you add to this thread here, telling us what your situation is AND leaving some contact details so that anyone who has the opposite problem and lives reasonably close to you can get in touch.

Viewing 24 replies - 51 through 74 (of 74 total)
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  • #29393


    Try three kinds of foods for Monarch butterfly caterpillars…

    Oxypetalum caeruleum tweedia

    Schinus molle Pepper tree

    Araujia sericifera moth plant



    If you got frustusted at not able to get swan plants to feed your too many big mature Monarch butterfly caterpillars #@**##…Cheers up!…PUMPKINS…Feed them on pumpkins…Chop the pumpkin into pieces & put big mature caterpillars onto pumpkins. Mature caterillars do well on pumpkins and pupaed well.

    Moth plants for young smaller caterpillars.



    Hi there, I have just read the posts here and I am so concerned about our caterpillars and the potted swan plants we just bought(from Mitre10, Bishopdale ChCh)to feed them.
    I realise now we should have researched before we bought them but we had so many caterpillars on our existing plants we thought we were doing the right thing buying food for them. Im worried that only after a day on these new plants if they have indeed been sprayed the damage is done.
    Could someone please advise me, as to what to do. My children will be devastated but should I remove them immediately and try and transfer them to other people, clearly I dont want to risk them getting sick.
    I am so disappointed that the retailers dont provide info on the plants – it wouldnt take much to have a sign saying “not suitable for caterpillar food as have been sprayed” “suitable for planting and prep for following season”
    Does anyone know where to buy SAFE plants
    Many thanks



    I have just been offered another lot of caterpillars from another nursery in Hamilton. Is there anyone in Hamilton, or out Rototuna side, with plenty of hostplant? I don’t know yet how many caterpillars are involved, but they will destroy them if we don’t take them.



    Looks like I’m playing the same tune as others.
    2 good sized swan plants and a sum total of two large caterpillars, neither of which are very big.
    Thing is, there’s plenty of evidence that there’s been other caterpillars, plenty of chewed leaves and a few tiny caterpillars! starting to wonder if the plants have been sprayed at some point and it’s killing the majority of the caterpillars.
    Must go and ask the garden centre about the plants being sprayed.
    Anybody in Wanganui, got caterpillars needing food?



    Today I had a call from a plant retailer who sells swan plants. He was concerned that the caterpillars were eating all his potted swan plants, and that they were quickly becoming unsaleable. People don’t want to buy plants that don’t have any leaf left!
    So he was offering me an opportunity to remove as many as I could, before staff were instructed to get rid of them.

    I thought it was very thoughtful of him to ring first. They have a lot of money tied up in these plants, and many retailers would have just quietly done the deed, and no-one need know. So good on The Plant Depot, Monarch Butterfly friends!



    When we were in Dunedin at Christmas we NEVER came across one Monarch;-((
    We did see a copper butterfly out by Port Chalmers though;-))
    I hope you get some soon Jennifer.

    Pepetuna – Bruce (Plant place) I agree his plants are great and good prices as well. We must call in and see him the next time we are in Hamilton. Which could be this weekend;-))



    Plenty of swan plant and milk weed no Monarchs here in St Clair, Dunedin



    People in the Waikato, especially around Hamilton, are lucky they can get big plants that won’t kill their caterpillars, from Bruce at the Plant Place next to Fresca off Kahikatea Drive. I went in there yesterday and his plants are beautiful big bushy things in decent-sized bags so they won’t run out of water as quickly as the plants you buy in small (potted-colour-sized) pots. There are also lots of wonderful nectar plants in there.



    We have sent out another press release about the dangers of pesticides on swan plants when looking for “caterpillar food”. Hopefully the media will pick up on the story and other people will know why their caterpillars are dying (if they are). If we can put the pressure on the growers to NOT spray their plants – or be up front about it if they do, it will be a huge leap forward. And if a few people plant more plants now for next year, that would be useful too.

    Here’s the guts of the press release:

    The Monarch Butterfly New Zealand Trust urges all butterfly gardeners to check out the swan plant they are buying to feed the most royal of butterflies, the Monarch.

    ?Right now many gardeners are upset that their caterpillars are dying,? said Jacqui Knight, Secretary of the Trust. ?People run out of milkweed (swan plant), and buy new plants from the garden centre for food for their caterpillars.?

    She said that in many cases plants have come straight from growers and have been sprayed so that they are in pristine condition. They are intended to be grown on in the garden, not used as caterpillar food.

    ?Both adults and children contact us, distraught to see their caterpillars dying,? she says. ?In many cases their caterpillars are their pets. How would you feel if you poisoned your dog??

    One enthusiast lost over 100 butterflies because she was told the plants she bought were ?pesticide-free?. Laboratory tests proved otherwise.

    While there are some growers who will never spray their plants, the Trust acknowledges that other growers find it difficult to grow plants without using pesticide, and cannot sell plants covered with, or damaged by, caterpillars. They are urging growers to plan ahead.

    ?Now is a great time to be buying seed and planting it,? said Jacqui. ?It makes a wonderful school holiday project ? and children really enjoy seeing their plants grow so that next spring they can plant them outside. And you will know that your plants are safe for your caterpillars.?

    ?More and more people are planting earlier, and making sure that they?ve got enough plants for the season. They?re protecting some of their plants so that Monarchs also lay elsewhere. And with good management, the plants are lasting several years, so there are cost savings too.?

    Information about how to produce plants fit for the most royal of butterflies can be found on the website



    Thanks Heather. I am in the Waikato, and it was the Mega at the Base (in Hamilton) where I bought the plants so most likely would be supplied by Auckland not Christchurch.

    Yes, I have changed the feedstock back to my home-grown plants. I will persist with the caterpillars that were affected, because they seemed a little better tonight. At least they were back eating again!

    I now have enough unsprayed plant to get through the next rush on resources, so hopefully will be able to last 3 weeks to a month. I might ring Zealandia and see if there was a problem & if so, what they used.



    I am Auckland so it was an Auckland Nursery.
    Ring Zealandia, Christchurch based, I am not sure if the Auckland one would send the plants down there.
    Put you plants away from the caterpillars, they will recover.

    get in touch with Mega they should know about the problem too and take the plants off sale, They should try and replace some of the plants with non sprayed ones.
    The poison would probably stay in the plant for up to 3 weeks depending what they used.




    Heather, can you tell us a little more about your post a few days ago about potted-colour-sized pots of swan plants being sprayed/

    “re the bunnings plants unfortunately if they were the small potted colour size plants.

    The boss of the nursery that grows them went on holiday and staff did spray them.
    The retailers were unaware that it had happened.

    They were removed from sale as soon as it was discovered that had happened.”

    Was this just the plants going to one retailer (Bunnings)? The reason I ask is that I bought 120 Zealandia plants labelled Asclepias from Mega, and the whole batch of caterpillars I have been feeding on it (a couple of hundred caterpillars) have sickened and stopped eating. They are literally starving themselves to death. About 20 have died, and it’s not NPV. They just stop eating, stop growing, and some die.

    I have changed them back to my home-grown milkweed, but I am worried
    a) that I will have to get rid of the plants or just keep them for seed and
    b) that I will waste good plant material on the poor survivors if they are never going to recover.

    Obviously, if other people have also bought plants from the same batch, they’re going to have the same problem if it has indeed been sprayed. If it was Zealandia, I need to know so I can ring them and find out what insecticide it was.



    Mitre 10 Waikanae had swan plants a few days ago, 3 for $10
    I may be able to supply caterpillers if i find more eggs on my plants. Kapiti Coast region



    Hi Adams family – the caterpillars writhing on the ground is a classic symptom of ingesting toxins. Generally speaking the staff that sell the plants have no idea what the grower has treated plants with and the marketing system avoids having plants on sale with leaves chewed by caterpillars. But I think the system is slowly realising that it is defeating the purpose selling swan plants to feed monarch caterpillars if they have been sprayed. Of course there is always the possibility of the plants copping overspray from neighbours or such. If the caterpillars are transferred to healthy plants they may survive, but no guarantees.



    Kings have beautiful plants (St Lukes, Auckland). Admiring them the other day. No spray on those ones.



    Char and Jacqui my mum has lots of swan plant food
    Char if the Te Atatu people still need help
    There are other people bring their excess caterpillars to her

    re the bunnings plants unfortunately if they were the small potted colour size plants.

    The boss of the nursery that grows them went on holiday and staff did spray them.
    The retailers were unaware that it had happened.

    They were removed from sale as soon as it was discovered that had happened.



    Hi all

    I’m hoping you can help. We had a large group of caterpillars from just one little monarch who found a seedling in our yard. We have been buying plants to feed them from Bunnings and while we had some casualties due to mantis and wasp attacks we still have 11 caterpillars left. After buying our second lot of swan plants from Bunnings almost all of them have gotten sick. I’ve never seen anything like it before, we had asked if they used pesticides and they assured us they didn’t. But these little guys are writhing in pain on the ground, they have green juices dripping off the plants and most of them look almost dead now. Do you think it was pesticide? If I get plants from elsewhere can I save the ones who aren’t dead yet? Some seem to come right after a while.



    You’re welcome Al. Your caterpillars are all settled in and happily munching away in the big swan plants I have here.



    Thank you C for assisting.



    I have around 40 Monarch Caterpillars, free for collection by anyone living near Howick. Would preferably need to be collected immediately as swan plants are now leafless and wasps don’t seem to have found them yet.
    If wanting to collect them, copy / Cc your reply to or phone 021 795 280.



    Hi Anasplace,

    We live in Massey, Waitakere City and are happy to help you out.
    Our email is as we have loads of swan plan leaves to feed hungry caterpillars.
    Or you can text me on 0211881853.



    Hi Anasplace

    We were in Kings Plant Barn yesterday in Takapuna and they had swan plants for $4.99 each. I would assume you would be able to find a similar deal in a plant shop over your way.



    hello to all out there and ahappy new year.
    i live in te atatu peninsula. i have quite a number of caterpillars on my swan plants and i know that there will not be enough plant left for those who are smaller.

    does anyonge want more caterpillars for their plants, or do you have extra plants.

    any suggestions would be welcomed.

Viewing 24 replies - 51 through 74 (of 74 total)

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