Ugly little vicious invader – help!

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    Wonder if anyone can help me. My swan plant has grown huge this year, some parts of it about 7ft or 8ft high.

    It’s been swarming with cats and in the past week about 15 butterflies have emerged.

    However in recent days I felt the cat numbers were falling so I had a nose around today. I noticed one fairly long cat was hanging backwards off one of the round pods so I went to give it a hand and found myself engaged in a tug of war for it with a strange, tiny insect.

    I got the cat free and realised this thing had speared it with a long, needle like object protruding from its face. This thing was very quick when I tried to get it and disappeared.

    The cat was dead and later started turning black. I noticed another cat, which had curled up as they do when about to have the chrysalis form, hanging from the underside of a leaf and it also had turned black.

    I found only about 12 living cats in total and would have expected three times the number.

    I then saw one of these insects stealthily inching towards another curled up cat but couldn’t catch the thing once more.

    I’ve removed all the cats to a second plant (including the curled up one, branch and all) but this plant is tiny and I think it’ll be denuded of all vegetation by tomorrow.

    Any ideas on what I can do? I’m too worried to put the cats back on the main plant.

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    Bernstein … yes, you must have the same bug. Like you, I considered spraying or something but though I now have removed all the cats to an ice cream container, awaiting the arrival of a castle in the post, I decided against it. For one thing, it would no doubt kill any eggs that monarchs have laid. Seems a bit silly to now have a huge swan plant without a single cat on it, but better safe than sorry.

    Jacqui … lots of helpful info, thanks.



    Thank you Jacqui for the info. I will let you know what I do. May not have the time to do anything, real busy fishing/camping etc.

    Will contact you re the seeds when mature.



    We would be grateful of the seeds at a later date, Bernstein, when they’re mature.

    We are just learning more about this bug, Cermatulus nasalis. There is a good resource here:

    I’m pleased I looked, as I have seen the 1st and 2nd instars before on my plants, and thought they were something else.

    Personally, I wouldn’t like to go the insecticide way as it’s going to destroy so much other life – put a big hole in your ecosystem. I would probably invest in another plant, leave it in a pot in another place elsewhere in your garden, and look for Monarch larvae/eggs and move them to the new plant. At the same time I’d go over the swan plant VERY carefully removing any of the C. nasalis stages that you can find. Are the existing plants growing near other plants? Because you’re going to find it very hard to eliminate the C. nasalis entirely from that area of the garden. If they don’t have Monarch larvae to eat they can “wander” to the plants next door to find other soft body insects.

    If you have brassicae or pear trees (for example) on or near your property, you would probably be grateful of C. nasalis as it would be preying on the Cabbage White or Pear Slug!

    Another article worth reading would be this one here.

    Please share what you learn and what action you take with us – and also if that works or what you would have done if it isn’t entirely successful.



    Back once more.

    The plants are doing so well that it has hundreds of flowers and seed pods forming, so if any one needs seeds later let me know.



    Back again.

    I have just looked up cermatulus-nasalis, tis the predatory shield bug. I’ll give them predatory, they won’t know what hit them, but I would like a bit more info if possible please.



    Thank you Delboy for reply.

    Yes, the cats are dark brown/black and look as if have been sucked empty. Is this cermatulus-nasalis a member of the wasp family.
    The ground beneath the plants is literaly sprinkled with dead cats.
    I have only joined with the Monarch Trust today so I am not up to date with other discussions on this subject. I feel quite upset about my poor little monarch caterpillars.
    I wonder, because there are virtually no cats on the plants now, if I sprayed with insecticide, and then covered the plants to protect the butterflies, may be the best longer term solution.



    @ Bernstein

    The two cats killed by this cermatulus-nasalis insect turned completely black, almost as if charred by fire. If yours aren’t like that, I don’t think you can have the same problem.



    @ Anna: thanks, I didn’t know about the castles, so I’ll be getting one. In the meantime your ice-cream container suggestion is a good one (not least because it’s an excuse to eat ice cream) and should keep the cats secure until the castle arrives. I did use some muslin cloth over a small potted swan plant last year when the problem was a preying mantis infestation, so I still have the cloth.

    Incidentally, I understood Monarchs didn’t take all that long to emerge from chrysalis form but I had one chrysalis under muslin in very late spring and gave up on it because it was taking so long — but it finally emerged in winter after five or six weeks. I had long given up hope but left the chrysalis hanging just on the off-chance. I was quite shocked when a lovely winter butterfly appeared.



    Our swan plants are also thriving this year, well over 2 Meters tall. Last year they were stripped completely bare. I found reason the plants are doing well, all the caterpillars are dead on the ground or wrapped around a twig. Is this the same problem as Delboy’s.
    Last year I was taking some of the last caterpillars inside and hand feeding them, hungry little buggars. I decided at the start of this season to treat them tough love, but maybe I shall have to reconsidor. There are large numbers of butterflies around which mostly come from a large Swan plant plot they have in Manfield Park close by.
    Any suggestions please.



    These horrible critters can do a lot of damage in a short time…and even have a guilty look when they see you!
    The best way to control them is to catch and squash them. They give off a horrible smell.

    For the caterpillars, I pick them off and raise them in one of the caterpillar castles that the trust sells, or raise them in a handy towel lined icecream container with a muslin cloth lid, held on with a bit of elastic (hat elastic I think its called)

    I cut bits of swan plant into small sections, and dip it in water to keep it moist, and make sure I change their container every day to keep them healthy.
    The caterpillars do their “J” on the muslin, before making their chrysalis etc.



    That is indeed my unwelcome intruder, thanks for that.

    Blown up to that size, it looks like something out of a science fiction nightmare. When it’s my time to go, I sincerely hope it’s not via something like this inserting a thin, six-foot long, sharp instrument into me and sucking out my insides.

    I can’t seem to find anything on google about how to remove or eliminate these nasties. If anyone has any thoughts, I’d be glad to hear them.


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