Scottish Rock Garden Club Forum
Bulbs => Galanthus => Topic started by: Palustris on January 30, 2012, 10:38:36 AM
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Do Lily beetles attack Galanthus? Only one was found yesterday on a clump of them, not sure if it was eating them or Alstromeria plant next to them.TIA.
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I get plenty of lily beetles on lilies and fritillaria but I've never seen one on a snowdrop, of which I have lots, not the adults nor the larvae (which you couldn't miss thanks to their excrement coverings and lack of mobility). I'm pretty sure they only feed on liliaceae.
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That's what I thought, well hoped. Not sure i want to spend as much time looking through our Snowdrop Wood for Lily beetles, bad enough chasing them off the few Lilies I grow. Thanks.
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I've seen them on Alstroemeria here so probably just exploring the new neighbourhood, lets hope they don't like it!
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This seems the right place to post these little *******
Some no shows in the garden caused me to have a look and see what was going on, I find eaten bulbs, roots and shoots - nothing left of 'Fieldgate Prelude' worth speaking of, and this is the reason. Swift Moth caterpillar, plump and enjoying a post prandial rest until I interrupted it. Sadly for him, he won't be feasting any more. It's about two inches long (5 cms), they can apparently live in the soil for up to two years munching merrily on bulbs, tubers and roots that get in their way >:( :-X :'(
Be aware!
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Brian you should start spraying with a systemic pesticide
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Don't worry Mark, I am. Even though the internet says that it will have no effect :-\
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The various 'Swift Moths' are unfortunately no longer common in this country. Indeed some species are very very rare. Its very hard to identify this one as (living underground, or in stems ) the larvae are not very coloured. The moths themselves are very beautiful and are an ancient ancestor of 'modern' moths. I fully understand the 'protect our plants at all costs' mentality that can prevail, but if these are found eating something common or locally abundant, please reconsider killing them. If they are on rarities, and can be removed alive, please consider relocating them. Most are pretty much polyphagous and wont mind being moved. Also just because they are with you this year, doesn't mean they will stay. The eggs are dropped in flight, and so the chances of there being many of them in one area, or a plague is minimal.
Moths in general are under great pressure in the UK and many many species are on the verge of extinction. How many of us get upset ( rightly ) when we hear about the Japanese killing whales, or the persecution of the Orang Utang? "People in glass houses .....!!!!
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The various 'Swift Moths' are unfortunately no longer common in this country.......
That is very good news.
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The various 'Swift Moths' are unfortunately no longer common in this country....
I'm sorry but in my experience these larvae are very common indeed and other snowdrop luminaries have reported problems with the same thing. Perhaps we are misidentifying the larva but it is a common problem for snowdrop growers. I have one under observation at the moment; would you like me to send it to you Ronm?
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If you feel it would help you, please do. Please pack with a little compost.
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I'd like to know what very common indeed means please. From my own observations ( over 40 years ) and many others across the country ( the adults come readily to light if in the area ) these moths are severely in decline. However, if we can survey and show hotspots, etc. maybe this can be reevaluated. Please e mail or pm me if you have these in your garden. Thank you . :) :)
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I seem to remember that Olive Mason's garden was suffering from swift moth caterpillar last year Ron.
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The various 'Swift Moths' are unfortunately no longer common in this country....
I'm sorry but in my experience these larvae are very common indeed and other snowdrop luminaries have reported problems with the same thing.
And not just snowdrop growers. Also growers of cyclamen, hepaticas & primroses to name just a few of the plants I've lost to these pests. In the case of cyclamen, two large populations nurtured over 20 years.
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I'm not saying they dont exist anymore ! And i'm not saying that one larva will not do damage. Its the nature of the beast. But if it can be tolerated, it will be gone next year more than likely. Unfortunately many people say 'Ghost Moth' when they have sawfly ( which are above ground and will be back year after year )etc. Not saying that in this case, as it seems to me you have ghost moth. IF they are targetting Galanthus, then this is very important, and we should try to collate as much data as to numbers and timings etc as possible. I am willing to be the focus for this on this forum. But I must have positive identification and numerical data. Otherwise its all hearsay and panic.
The ghost moths lay on the wing and therefore do not identify larval foodplants in the same manner as most other Lepidoptera. Doesn't mean that they cannot somehow smell Galanthus in the air while flying past.
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Yes Gerry, they will eat most anything. You are very unlucky, :( :( :(
Seriously if anyone finds one in their garden, UK only please, please PM me for my address, pack it in a small amount of compost and send it to me. I will of course pay P&P. Lets see if we can show that these are not an endangered genus in UK.
I will tally up all identified Ghost Moths received, and post regularly here to help the forum appreciate the problem and perhaps any hot spot areas.
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For those interested,
http://www.bugsandweeds.co.uk/moths%20p3.html#OrangeSwift
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or
http://www.animalphotos.me/moth-swif.htm (http://www.animalphotos.me/moth-swif.htm)
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Maggi, may I set up a seperate thread to record these sendings?
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Maggi, may I set up a seperate thread to record these sendings?
Of course. :)
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Its the nature of the beast. But if it can be tolerated, it will be gone next year more than likely.
Surely the nature of the beast is to lay its eggs where it found a food source? I find lots of these larvae around my garden. Last year I found two larvae in an empty plant pot that formerly contained two bulbs of Galanthus plicatus "Trym". There were no bulbs any more, just the larvae. When both were placed in the same small container they quickly fought each other to death!
I used to have a random mixed clump of Galanthus and Leucojum aestivum. Last year the Galanthus had gone, suggesting something had 'cherry-picked' them from out of the clump. I suspect this indicates that the larvae have a taste for Galanthus bulbs, or possibly just small bulbs. It would be very interesting to test this by offering some captive larvae a choice of different bulbs to eat.
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I'm not saying they dont exist anymore ! And i'm not saying that one larva will not do damage. Its the nature of the beast.
Yes Gerry, they will eat most anything.
So we should love & cherish them? All God's creatures.
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Alan, while I honestly believe what you have seen, this is amazing news if they were Swift / Ghost moth larvae. As the larvae are subterranean their behaviour is mostly unknown. Maybe cannibalism does exist if two meet? Never before recorded ( to my knowledge) but not unimaginable in a species with this type of feeding habit. Strangely in these cases the adults don't seem to seek out a food source, safe in the knowledge that the larva will eat almost anything it finds, therefore not seeking of specific foodstuff. Unfortunately due to regular cultivation and pan generic insecticides the genera has found itself under immense pressure despite its polyphagous nature. If you find one photo it please ( and send to me ) then move it to a patch of weeds some way fromyour garden, or send intact to me ( 1st class please ).
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Gerry, thats up to you. You are responsible for your own actions.
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I assume you got my PM Alan and that you will send them ASAP. Thanks, ;)
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New thread started on General/ Ghost Swift moth. Please help us record.
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Yes, Ron; I only have the one captive at present. I'm sure I'd find more if I went digging in the garden.
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Thanks Alan. If you do please let me know. But please, as best you can, try to make sure they are the same as the one you are sending me. Since the first post I have been 'swotting' through all my ( extensive) literature, and there is no evidence ( that I can find )ever of species of this genus targeting plants of a single genus. If we do the graft over the next few years, maybe we can show this is / is not the case. Thanks for your cooperation. ;)
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P.S. There are a myriad of soil dwelling beetle larvae that superficially resemble these moth larvae. i.e. white opalescant bodies and dark heads. These can be ( depending on species ) beneficial or harmful to the flora of the garden. If in doubt collect them alive and move them somewhere else. ;)
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Ron's new thread is here http://www.srgc.org.uk/forum/index.php?topic=8723.0
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The thing about these larvae is that one can do a lot of damage. They don't have to be common for that one rare caterpillar to be in your favourite clump, where it could munch the bunch in two years! :o
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If I lift and divide my snowdrops I can be fairly confident that I will find these larvae. So even if they are rare in the country as a whole they are common in my locale. They may not be sufficiently common to have eliminated the snowdrops from my garden but they are making valiant attempts. I'd even be prepared to do a certain amount of live-and-let-live with my more common/prolific snowdrops if I could find a way of excluding them from certain areas. For example, perhaps a fleece covering at the time of year when the moths are laying their eggs would do the trick? I used to keep my snowdrop that are in pots under a hedge in summer and that seemed to work but now I have too many to do that and the larvae are getting into the pots.
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The adults are on the wing in June usually Alan. The female will drop the eggs whilst in flight, so a covering of some type may well help. Say from beginning of May to end July to be safe.
It is obviously reached pest proportions with you, and I am at a loss really to understand why. Is your growing area totally surrounded by a high fence or hedge? The egg laying strategy of these moths is to widely broadcast eggs rather than lay in clumps. Perhaps you had a single gravid female that was unable to fly and laid all ( hundreds ) of her eggs in your garden. Have you had this problem for many years? I'm afraid the only control method is 'hand picking'. But if they are trapped there then they will only return in future, as you'll never get every last larvae.
Interestingly I can find no documented evidence, so far, of this being a recognised pest of Galanthus. Narcissus fly, yes, everywhere. But this moth no. Maybe because 'drops aren't grown on a massive scale?
No need to live and let live with your common 'drops though Alan. If there is a local patch of rough ground, pop them on there. They eat much anything, but grass roots have always been thought to be the primary foodstuff. Even when present on grass their is no damage noticeable.
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Hmm, Galanthus leaves usually die back some time in May. I would like a covering that lets enough light through that I don't unduly hasten this process, that lets water through but has a fine-enough weave that the small eggs of a swift moth would be trapped. Any suggestions? Presumably such a covering, if it exists, would also work against narcissus flies.
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Would a standard horticultural fleece not suffice? It works perfectly against narcissus flies, so long as they can't get under the edges.
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Quite possibly horticultural fleece would do fine; it's just that I don't normally use fleece so have no experience of what it can and cannot do. Is there more than one thickness/density or is it entirely standard?
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I'm unsure about various grades etc. Alan. We use the regular stuff from the garden centre to keep the insects off our vegetables, so I'm sure it would work for you. Just ensure the edges are tight to the ground. Probably best to cover the edges with a little soil or sand to ensure no gaps.
It will have to be a war of attrition though Alan I'm afraid :(. If you have as many as you think then you must have one year old and two year old larvae present, so you may have to take the long view. If you do cover your 'drops then you will find the adult moths trapped underneath around June time. I'd check daily if possible, early morning being best. Hopefully by taking the adults you can gradually reduce the population. They are also very much attracted to light ( especially the females ). It may be worth keeping an eye on house windows etc. during the flight time.
Also the egg laying period of the narcissus fly is early May to June so by covering you may help avoid this problem as well.
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I was talking to a vegetable-growing colleague over lunch. He reckoned the main problem with using horticultural fleece was that things can over-heat underneath it.
Do you think the moths could still meet, mate and lay eggs in the confined space under a fleece?
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I'm pretty sure they could Alan. :(