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Weeping Blue Cedar with mites?!?

Last post 15-06-2009 2:15 PM by Mehetabel. 2 replies.

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  • 14/06/2009 09:17 PM
    • Mehetabel
    • North Yorkshire
    • 14 Jun 2009
    • 2
    Not Ranked
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    Hello,

    We have a mature weeping blue atlas cedar which seems to be under attack from mites. Some major branches are covered in dark sticky sap, some mites are visible, and many needles are turning yellow and falling off. Any help or advice most appreciated as it seems to be getting worse quite fast!

     The tree is in a south-facing aspect, shaded from midday sun by a nearby larger tree. New growth has appeared this year and apart from the terrible state of the affected branches the tree is otherwise healthy.

     Many thanks...

    Mehetabel

  • 15/06/2009 07:50 AM
    • Pesty
    • At a desk
    • 24 Nov 2005
    • 324
    Top 50 Contributor
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    Stickiness = possibly honeydew = sap sucking insect infestation. In the case of cedar probably the cedar aphid - see below. If the tree is small enough to spray then insecticide is the answer (synthetic or organic - synthetic pesticides are more likely to give the desired results quickly, organic sprays may need to be used on several occasions). If the tree is too large to spray then there is not much that can be done.

     

    Cedar aphid (Cedrobium lapportei)This small aphid is 1.5-2mm long and greyish-brown with a paler mid-dorsal stripe running from the head end.  It infests cedars including Cedrus atlantica, C. deodora and C. libani.  Dense infestations occur at the bases of the leaves during May and June, and this can result in the affected leaves being shed.  A large quantity of honeydew is excreted which makes the foliage sticky.  Sooty mould frequently develops, both on the tree and on the ground underneath where honeydew has accumulated.

     

    'Trying is the first step to failure' H.J.Simpson
  • 15/06/2009 02:15 PM
    • Mehetabel
    • North Yorkshire
    • 14 Jun 2009
    • 2
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    Sounds exactly like the problem I have. Thanks very much for the very helpful advice - I'll get some insecticide. The tree is only about 10 feet tall so shouldn' t be a problem to spray.

    Many thanks!