Viburnum leaf damage

Discussion in 'Garden Pest Management and Identification' started by Lysichiton, Jun 24, 2008.

  1. Lysichiton

    Lysichiton Active Member

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    One of the properties we are involved with has a variety of Viburnum which is getting eaten. Never seen this before in the Fraser Valley BC. Hunting around I see refernce to the Viburnum Leaf Beetle. The damage seems to fit & is quite specific to the Viburnum.

    Has onyone else come across this thing? Had any luck with control?

    The landscape planting is 2-3 years old & I suspect this came in with the original stock. Darn it.

    gb.
     

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  2. Ron B

    Ron B Paragon of Plants 10 Years

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    There are previous threads on this site. try searching if you haven't read them yet.
     
  3. Lysichiton

    Lysichiton Active Member

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    OK, I'll search. Thanks.

    gb
     
  4. jimweed

    jimweed Active Member 10 Years

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    I deal with them all the time. Not that easy to control, but it is possible. Larvae and adult do the same damage. If you are able to target them when present during each life cycle you can knock them back. Google them for their life cycle and identification then visually look for their presents and spray them. Dormant spray can be effective in slowing them down too.

    Although I can see even from a distance that a lot of the large holes you are witnessing are more likely cause by some sort of environmental stress to the roots. If you look around your landscape I am sure you will see similar large clean holes on otherwise healthy looking leaves on various plant material, (commonly between veins).

    This beetle will notch out one side of the leaf. Leaving brown streaks and eventually rough looking holes. To be honest I can spot from your pics some damage from this beetle, but it is not yet as severe as it is going to get in time, if you do not try to control these.

    Something systemic like Lygon, or even Merit might be your best chance if chemical control is pursued. You could use a contact insecticide when you see them. If you are careful on a cool evening you might get away with using Lime Sulphur on the larvae stage, it may not be as effective on the adult without having to mix it too strong. In the summer months you must be gentle with sulphur.

    I am not sure what is available on the market for you to use, those were just some suggestion on what will work. Good luck,, Jim.
     
  5. Lysichiton

    Lysichiton Active Member

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    Thanks. I think it would be easier to replace the plants & probably less expensive in the long-run, since we haved to pay a landscaper to do the work. It would also cause less consternation among the owners, many of whom do not want to spray pesticides.

    gb
     
  6. Ron B

    Ron B Paragon of Plants 10 Years

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    I seldom plant rhododendrons anymore for similar reasons - in this case the arrival of a nasty foliage mildew that has become pervasive in this region. The likelihood of bamboos getting full of mites is also a bore - although I still plant those. Often it is highly popular groups of plants such as these that are subject to serious banes, there being plenty of them around to support the buildup and spread of high levels of pests or pathogens - all the more reason to choose less usual fare instead.
     
  7. jimweed

    jimweed Active Member 10 Years

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    If you are in a strata and it sounds like you are, it might be a good idea to consider removing them if they continue to be infested. They seldom control themselves once the infestation sets in, and spraying insecticides around strata's is never a good thing.

    I was looking at your picture again and now I can really see the damage all over. The sun kind of reflects a bit and at first I didn't see all the streaks.

    Hopefully you don't have a lot of them planted.

    Jim.
     
  8. Lysichiton

    Lysichiton Active Member

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    We manage this property & a lot of others (for our sins :)). The comments of both of you make sense & accord with my experience. Some candidates I have in mind to replace this evergreen broad leafed shrub are:

    Choisia , Ceanothus, Camellia, Escallonia, Eleagnus.

    Depending shade & exposure.

    any other bright ideas?

    gb
     
  9. Ron B

    Ron B Paragon of Plants 10 Years

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    Choisya, ceanothus and escallonia are best on hot walls out of cold winds, otherwise there may be periodic frost injury. Cold heavy soils are also to be avoided with these. Perhaps the best ones in this region are Ceanothus 'Victoria' (possibly the same as 'Skylark') and Escallonia 'Donard Seedling' (usually sold under the misapplied name 'Apple Blossom' which actually belongs to another, different cultivar rarely seen here).

    Also liking wall treatment here is Camellia sasanqua - primarily because of its habit of flowering in fall and winter. Early kinds that bloom in October may not require such placement. These grow well in full sun, with the additional advantages of often having loose, willowy growth habits producing a more relaxed feeling than the often dense and lumpy C. japonica, and are also often markedly fragrant in flower. C. japonica requires partial shade for best appearance, must be placed where morning sunshine after frost will not strike the flowers, are prone to camellia petal blight here and produce incredible amounts of brown, spent flowers - some of which stick to the shrub rather than dropping - even when not blighted.

    And most cultivars are not fragrant.

    Elaeagnus are fragrant and the evergreen ones grown here flower in October. But on the whole these are rather stiff shrubs producing large, boxy lumpen mounds of growth in time.

    Speaking of box, this remains a stalwart although not without its own problems. Japanese holly may tend to have a better (glossier) leaf appearance but is not available in such a range of growth and foliage types as box, which has been grown in western gardens for a long time. The holly also swarms with bees at flowering time, and is prone to notching of its leaves by weevils in locations where noticeable damage by these is likely (under evergreen trees and building overhangs).

    To get flow in a planting you do want to have the majority of bed space occupied by small-leaved shrubs such as these. A common mistake is to plant mostly medium- to large-leaved specimen-type shrubs with unfilled spaces between, these often maintained by excessive pruning even where the plants might otherwise grow together in time to produced a superior finished appearance.

    The old original copyrighted 1943 version of Grant/Grant, Trees and Shrubs for Pacific Northwest Gardens contains this list.

    TWELVE BEST ALL-ROUND BROAD-LEAVED EVERGREEN GARDEN SHRUBS FOR FULL SUN

    Abelia grandiflora
    Berberis darwinii
    Camellia japonica var.
    Camellia sasanqua Briar Rose
    Escallonia langleyensis
    Mahonia aquifolium
    Osmanthus delavayi
    Photinia glabra
    Rhododendron augustinii
    Rhododendron ciliatum

    Vaccinium ovatum
    Viburnum davidii


    Obviously I don't agree with placement of Camellia japonica in this list - either as a good all-rounder or as a shrub for full sun. The mess the spent flowers make really is remarkable and yellowish leaves, burnt-looking flowers are very common among those seen planted in exposed positions here.

    Nowadays 'Briar Rose' would not be one of the C. sasanqua cultivars likely to be encountered at local outlets. 'Donard Seedling' would be much more often found than stock offered simply as E. langleyensis. And its hybrid 'Cilpinense' would be planted instead of Rhododendron ciliatum - except by rhododendron enthusiasts or others purchasing outside of the normal realm.
     
  10. jimweed

    jimweed Active Member 10 Years

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    Man, there is a guy who really knows his plants! Nicely done Ron.

    Me personally wouldn't know Pine tree from an Apple tree have the time. But I can recognize Viburnum Leaf Beetle damage from a block away! That is the only way I can tell that plant is a Viburnum.

    GB, post a wide angle shot so Ron can narrow down your selection, Lol. Jim.
     
  11. Lysichiton

    Lysichiton Active Member

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    Ron,
    Thanks for your knowledge & time in that reply! Now I can give the appearence of knowledgability!

    gb
     

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