Dappled Willow - Aphids

Discussion in 'HortForum' started by Irena, May 12, 2021.

  1. Irena

    Irena New Member

    Messages:
    9
    Likes Received:
    1
    Location:
    Vancouver, BC
    Hello,

    We planted a dappled flamingo willow (tree form) in our front yard last fall. It gets lots of sun and looked wonderful and lush a few weeks ago.

    This is the first spring for this tree, though, and it is now completely infested with aphids. I caught it relatively early (or so I thought), and have been treating it once a week with a neem oil/dish soap solution. I also put sticky tape around the trunk to keep the ants from running up and down to farm their aphids. But the tree is looking terrible and every day I find more aphids on the plant. They hide in curled up unbudded leaves, so it takes a solid couple of hours to spray every branch and get into every nook and cranny. I tried to acquire some of its natural enemies (e.g. ladybugs), but apparently those won't be available for sale until summer. I found three or four ladybugs on the tree initially but they weren't getting the job done and have since packed up and moved on.

    I have two questions: is my tree more vulnerable to this infestation this year because it isn't yet established or is this a sign that this tree will probably not thrive here? (If it is the latter, I will need to contemplate replacing the dappled willow with a tree that is more likely to thrive here.) Is there anything that I can do that is more effective than what I am already doing?

    Many many thanks in advance...
     
  2. wcutler

    wcutler Esteemed Contributor Forums Moderator VCBF Cherry Scout 10 Years

    Messages:
    9,491
    Likes Received:
    1,482
    Location:
    Vancouver, BC Canada
    This is not an answer - I know nothing about this, but I want to ask - wouldn't you want the ants to farm the aphids? And might the ladybugs have moved on because they don't like the neem oil/dish soap? It seems like you're doing what you can to thwart the predators. Really, I hope someone who has dealt with this will respond, but in the meantime, could you reply with photos of the tree when it looked wonderful and lush and what it looks like now? Attach photos and files.
     
    Georgia Strait likes this.
  3. Irena

    Irena New Member

    Messages:
    9
    Likes Received:
    1
    Location:
    Vancouver, BC
    Thank you so much for your reply. My research suggested that the ants protect the aphids from their natural predators, so limiting access for the ants seems to be a part of the recommended approach in getting the problem under control.

    I've attached the before/after image, though I have to say that it looks much more scraggly and brown in real life than in the photo. (We added fresh topsoil recently, which is why there is missing grass in the after photo.)

    What I am seeing close up is that the tree is losing many leaves and so is developing bald patches.
     

    Attached Files:

  4. vitog

    vitog Rising Contributor 10 Years

    Messages:
    1,580
    Likes Received:
    176
    Location:
    Burnaby, Canada
    Ants definitely protect the aphids and need to be controlled. They probably brought the aphids to the tree in the first place. I have 9 fruit trees that always have ants trying to farm aphids, and I use Tree Tanglefoot around the main trunks to keep the ants away. It certainly reduces the aphids and allows the ladybugs to prey on them effectively. If all else fails, you could use a Malathion spray to kill the aphids, since you don't seem to be growing any edibles nearby. I would try insecticidal soap first.
     
  5. Irena

    Irena New Member

    Messages:
    9
    Likes Received:
    1
    Location:
    Vancouver, BC
    If ants brought them up the tree in the first place, then I have some hope for this tree's future as that is relatively preventable moving forward. But managing an existing infestation seems impossible with this plant. Three days after the last treatment and already there are new aphid colonies encircling new growth. I don't know if these are the result of a new aphid landing on the tree or a few existing ones that were tucked away in the tender new growth, got missed, and reproduced. Sigh. I suppose insecticidal soap is the next step.
     
  6. Daniel Mosquin

    Daniel Mosquin Paragon of Plants UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

    Messages:
    10,315
    Likes Received:
    458
    Location:
    Vancouver, British Columbia, Canada
    I don't envy you -- so much surface area on those leaves with a lot of places for aphids to hide.
     
  7. Irena

    Irena New Member

    Messages:
    9
    Likes Received:
    1
    Location:
    Vancouver, BC
    It really is an impossible task. I spent well over an hour spraying every single leaf and opening up the new growth so that I could reach the hidden nooks. But so many leaves. So many many leaves.
     

Share This Page