Saving our buddleias

This topic contains 6 replies, has 6 voices, and was last updated by  kay2 2 years, 5 months ago.

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  • #47800

    Jacqui
    Moderator

    Buddleias have always been a fantastic source of nectar in our gardens. Until about five years ago Cleopus japonicus was introduced: the buddleia leaf weevil.

    I have been looking for ways it might be controlled without using sprays. I read this:

    http://www.ent.uga.edu/personnel/Braman_articles/1999/Gradients%20in%20Susceptibility%20and%20ResistanceMechanisms%20of%20Buddleia%20L.%20Taxa%20to%20the%20Two-spottedSpider%20Mite%20(Tetranychus%20urticae%20Koch).pdf

    A second mechanism that may affect arthropod herbivory in
    Buddleia taxa is the presence of highly branched, nonglandular
    trichomes (Rogers, 1986). Although the ability of these trichomes to
    prevent herbivory is not well characterized, there is evidence that they
    are defensive structures that limit arthropod feeding. Cleopus japonicus
    Wingelmuller, a weevil that is host specific to Buddleia, avoids the
    trichomitous undersurface of B. davidii leaves (Zhang et al., 1993)
    and feeds on the upper surface. This feeding behavior indicates that
    mechanisms present on the underside of Buddleia leaves, most
    probably trichomes, are affecting the weevil’s ability to feed successfully
    on this portion of the leaf.

    A trichome is ‘a small hair or other outgrowth from the epidermis of a plant, typically unicellular and glandular’.

    So I’m wondering if we could perhaps spray our buddleias with a substance that would have small fine hairs in it (and something to stick it to the leaves) and that would deter the weevil? What do other people think?

    Jacqui

Viewing 6 replies - 1 through 6 (of 6 total)
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  • #49945

    kay2
    Participant

    Be great if something was worked out. I took out our buddleia (large)last year as it had got to the point where even though i was picking off the weevil every morning the leaves were destroyed, each year it got worse, 2 to 4 weevils on most leaves.

    #49884

    Dane Keriboi Hawker
    Participant

    I have about 20 plants doing well in Kerikeri. No signs yet. When do they start showing the most? If I get some I will spray with Acelepryn. If you deadhead then spray I dont see any problem as the cats dont go on them.

    #49877

    ChristinaH
    Participant

    Last year my buddlia wee affected by the weevil, not wanting to spray I pruned them back hard and they have regrown. They still have evidence of the weevil but seem to be surviving with it.

    #47840

    susan
    Participant

    I was just wondering if all buddleias are affected equally by the weevil. This is my first summer growing them. Of the 3 types I have the sungold is the only one affected so far. It is covered in the little beasties, but a purple/blue flowered one with silvery leaves which is within touching distance of the sungold is not affected (yet). A ‘rainbow’ Buddleia a bit further away is similarly unaffected. I’m thinking about a cleanup prune and spray, but the time for this is not yet as there are still flowers remaining for the butterflies.

    Susan (Hibiscus Coast)

    #47836

    Stefan Olson
    Participant

    I noticed the other day having moved from Bayview to Northcross that the buddleia cuttings that I brought were looking very well eaten. It turns out that we have the weevil up here (I’m assuming it came from here, as I had no problems before moving). So I’m interested in ideas to save my buddleia next season. I have managed to kill off all the weevils on the cuttings thus far, but as the plants get bigger it’s going to be a much tougher job. Very sad.

    #47834

    Jacqui
    Moderator

    Norm – what are your thoughts? Terry, would appreciate your thoughts on this too…

Viewing 6 replies - 1 through 6 (of 6 total)

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