help please for sick caterpillars

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  • #32709

    Anonymous
    Inactive

    I have seven caterpillars that have been inside on a swan plant since eggs – 6 were eating our milkweed for 2 weeks and a 7th a few days younger. We got 2 new plants and in the afternoon the 6 larger ones moved onto a new plant and were all eating away. The next morning the 6 were oozing green stuff, not moving and some had fallen onto the soil. They seemed to be dying. The shop assures me the new plants were not sprayed but I took them away anyway, brought plants from another shop and they stopped oozing and are generally quite active again although not eating and don’t want to stay on the plants.

    I’m not sure whether they are too unwell to eat, big enough to stop eating and think about making cocoons, if I should leave them or be doing something. Any help would be much appreciated.

Viewing 17 replies - 26 through 42 (of 42 total)
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  • #33011

    NormTwigge
    Participant

    Hi Gillian,

    Deflated looking caterpillars can be the result of being sucked by a predator such as a soldier bug or spider, and this can be on all sizes of caterpillar.  The bottom two photos show what looks like a wound on the back of the caterpillar, and there are a number of parasitoids (flies and wasps) which lay eggs on the caterpillar, and the emerging grubs bore into the caterpillar and feed on the internal contents of the host.  The caterpillar, mainly late instar at this stage, goes very lethargic and eventually the grub bores its way out of its shrunken host, leaving a hole or wound in the skin of the caterpillar,  and pupates.

    Generally the parasitoid emerges from its host before it dies.  It would be very informative to put a caterpillar that is still alive into a jar and see what emerges, or freeze the caterpillar and cut it open to see if there is a grub inside, either will be proof of parasitism as there is not much in references on NZ monarch parasitoids.

    If  it is one of these parasitoids the emerging grub usually pupates in the ground or leaf litter.

    #33004

    Jacqui
    Moderator

    Gillian’s photographs are here.

    She would very much appreciate any helpful advice. Have you had anything similar? What did you find out (from research or the scientific community)?

    Gillian Eadie’s dying caterpillars

    #32957

    Jacqui
    Moderator

    Hello Gillian – how many caterpillars are you talking about? And could you send a photo to photos@monarch.org.nz?

    It will need to be very clear, for us to be able to help though.

    #32956

    Gillian Eadie
    Participant

    Well, the Plant Barn assure me that the plants came from an organic nursery and I guess I have to take their word for it. They also said I am the only one who has contacted them so maybe it is something local to me … but it is so upsetting.

    The caterpillars go limp in the middle and some of their legs stop working (or disappear). They lose body condition, are floppy and appear deflated. And they are not eating much …..

    I’ve looked for all the things that it might be – not enough sunlight (although it has been pretty sunny in Auckland), ants (I’ve found some running around, particularly round the dead caterpillars, spiders? (I found one on a leaf next to two tiny dead bodies), too much garlic in the aphid spray, or something that I haven’t discovered yet but I hope to find out about at the conference! I have about 100 chrysalis on their way so I am hoping whatever it is hasn’t affected them …..

    Thank you for your help and good sense. I’m trying to think ‘That’s life’ but I really want to be able to fix things for them!

    #32907

    Caryl
    Participant

    I was at a nursery (not Mitre 10) in Wellington and Zealandia swan plants were on sale. They looked as if they had been sprayed beccasue the leaves had white spots on them. They almost looked too healthy and no signs of eggs or cats. I had a word with the buyer who really didn’t seem to care. I was polite and alerted him to the fact that Zealandia ones at Mitre 10 were likely to have been sprayed. He believed monarchs were not native and therefore he valued them less than the admirals. I will now only buy Lansdowne ones.

    #32903

    Jacqui
    Moderator

    My personal opinion is that it not ALL growers have to spray their plants. I believe my supplier when he says they’re spray-free.

    There are ways of talking with the growers/retailers and getting their support, making them aware of our concern that plants should be safe for caterpillars to eat – as safe as their vegetable seedlings are safe for humans to eat – and plants in their their organic and/or biodynamic range(s) have never been affected by pesticides.

    I’ve been working with retailers for some years now and have got a positive response from them when I’ve talked with them. When they’ve had the situation explained to them they have a good understanding of the issue. It isn’t necessarily counterproductive. The retailers don’t like having unhappy clients, knowing it will affect their business.

    It’s all part of the education process. Many garden centre retail staff will say to customers that “Buddleias are weeds” and “Lantanas are weeds” and this isn’t true. We need to raise the awareness.

    You’re right, Kate; it is an important role for us to take. We need to put a lot of thought into this. Perhaps in the meantime we can encourage more members to plant more plants this year, keep some free of caterpillars so that the plants are full-size next year for next year’s food supply.  If you grow it, you know what’s gone onto or into it. Also, planting seeds (or letting plants grow wild in the garden) is another move so that there isn’t a dependence on buying plants that might have been sprayed.

    #32898

    Gillian Eadie
    Participant

    That’s a good point, Perpetua. If someone has the specific knowledge then I am hapy to help spread the word. When the caterpillars first started dying, I wondered if the garlic – dishwashing liquid – oil spray that I have been using to control the Oleander Aphid was the cause of the problem …. could it be? I have  been pretty careful about where I sprayed it and the recipe came from the very best of authorities!!

    Kindest regards,

    Gillian

    #32897

    Pepetuna
    Participant

    It’s not going to be a popular point of view, but I think we need to face up to the fact that all growers have to spray their plants. If we run to the retailers and/or then the growers and say: “Have these plants been sprayed?” it will be counterproductive and put them in a bad position of having to tell lies or try to shift the blame to someone else. What I believe we need to do is to identify the sprays that CAN be used (i.e. non-systemic ones) and provide clear guidelines about with-holding periods (how long it is before they can display them for sale in their stores) and avoiding spray-drift in retail and grower locations. Who has the knowledge/inclination/contacts to do this? Or be part of a team that does it? Hands up PLEASE!!!! It is an important part of the role of the Monarch Butterfly New Zealand Trust to take a lead with this issue, because we have faced it every year that I can remember, and you know the old adage: If nothing changes, nothing will change.

    #32896

    Gillian Eadie
    Participant

    Thank you for these comments and replies. I am also distraught to find that some of my caterpillars are dying. I’m in Auckland and have been a regular purchaser of swan plants (as well as growing my own frantically but nowhere near fast enough!) but during the past week I’ve lost eight caterpillars so far and I know there will be more because there is a large number of very sluggish caterpillars on the plants. Same symptoms – green ooze then finding the little deflated bodies at the bottom of the plant stems. I have a call into the Plant Barn where I am a regular customer (and over the past month I have bought from three different deliveries of plants) so I will share what I find out. The assistant who took the call said that they don’t spray them in the Plant Barn but I am worried about where the latest supply came from.

    I’ll follow your advice Jacqui re not bothering the caterpillars too much and hope they recover but it is very sad after all the tlc they get every day  …

    Gillian

    #32891

    Jacqui
    Moderator

    The plants should be safe for next year’s critters – can you plant them somewhere where they’ll get some cover/protection from the winter weather? If you’ve got a warm location they may be great for next year.

    I hate hearing about this sort of thing happening.

    #32890

    Anonymous
    Inactive

    An update on my sick caterpillars.

    I contacted the retailer who pleasingly was very responsive and who immediately rang the grower – located well south of ChCh.  They denied spraying and concluded it was likely caused by spray drift onto my property (overnight onto a sheltered patio over 20m from the nearest neighbour).  I was also apparently the first person to report such an occurrence.

    Have now purchased more plants from my original garden centre source, who grow them in-house in ChCh.  They advised many people were coming in reporting the same symptoms and seeking ‘safe’ plants.

     

    About two-thirds of the 15 odd sick caterpillars recovered after 48 hours of violent illness following transfer onto the safe plants.  The rest died (they were all the smaller ones).  Many of the surviving caterpillars have pupated but the chrysalises are small, one died mid-pupation.

    Thinking laterally, if it is not spray on the plants then what is it?  Could it be something in the potting mix which is being absorbed into the plants – a fertiliser or anti-fungal…  Or, as has been mentioned on this site, are there more toxic variants of the swan plant being propagated by some growers and the caterpillars cannot cope with the transfer from a lower to higher toxicity plant.  Boffin required to sort this out please!

    Anyway, have watched 6 butterflies emerge and take flight in the last 48 hours, always a wondrous sight and more to come.

     

     

     

    #32770

    Jacqui
    Moderator

    Thanks for updating us, KittyCat. I’m glad you got to the bottom of this. It is very disappointing, though, isn’t it?

    #32769

    Anonymous
    Inactive

    we returned our plants and got our money back on principle from mitre ten. they contacted the supplier today zelandia who are adament their plants were not sprayed and blamed the sudden caterpillar deaths on gusts of a neighbours spray. it is besides the point to them the caterpillars have been kept inside since eggs and that the one caterpillar who did not get sick stayed on the old plant and the 6 who did get sick moved to the new plant. they offered us more free plants – no thanks.

    #32762

    Caryl
    Participant

    Kittycat where are you in Wellington? I am in Seatoun. I even had someone at Palmers tell me to spray the swanplants to stop females from laying their eggs!!!

    #32713

    Anonymous
    Inactive

    Snap.

    I’m in Christchurch, have about 20 cocoons happily waiting to hatch, but ran out of food for the last batch of caterpillars so rushed out Friday afternoon (15th) and got three small swan plants from  a different garden centre than I had purchased from previously.  On Saturday morning found four writhing oozing mid-sized caterpillars and now the larger ones are sickening too.  Everything I read online is pointing to poison.

    Will be contacting the retailer first thing tomorrow, did not see a sign warning not to be used for food this year. Quite distressing.

    #32712

    Anonymous
    Inactive

    We’re in wellington. the old plants (zealandia) have gone back to mitre 10 (Petone).we have read that a change of plant can upset them too, would you say this sounds like a reaction to the new plant or poisoning? we have given them some new plants from california garden centre (lansdown – which came with happy caterpillars on them) and they seem a bit better (no more green goo). theyre not all eating though, some just walking around not on the plant, these are almost 2 weeks old now so is it ok to leave them off the plant or try to help them back onto it?

    thanks! 🙂

    #32711

    Jacqui
    Moderator

    Whereabouts are you, Kittycat?  It’s sometimes helpful to know that as there might be one of us a bit more experienced living close by who could share plants with you. Also, in some areas we’ve developed relationships with growers/garden centres who we are confident sell plants that haven’t been sprayed.

    The symptoms do sound like poisoning. As you can imagine, it is quite possible for people in garden centres or the growers to not know if plants have been sprayed or not – and on a few occasions we’ve heard of plants being sprayed by accident, or by one person who goes against the wishes of everyone else in a nursery/garden centre. Growers want to sell their plants (they don’t necessarily have healthy caterpillars in mind) and garden centres want to sell them too – and all their other plants need to be in pristine condition to sell. So… you may never know if your plants have been sprayed or not.

    I would leave the caterpillars on the plants they’re now on. Try not to interfere with them too much, they may recover. Let’s hope for your peace of mind that they do. The “bad” plants – I suggest you water them well and plant them out in the garden. Depending on where you are in NZ, if they get shelter from snow/frosts/excessive wind, they will be great plants for next year. You might want to cover them up so no Monarchs lay on them this year.

    Hope that is helpful.

     

Viewing 17 replies - 26 through 42 (of 42 total)

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