Possible wooly aphids on western crabapple - Ask Extension
Can someone confirm if these are wooly aphids on my newly-planted western crabapple trees? I have no idea where they came from (I've notified the nurs...
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Possible wooly aphids on western crabapple #872732
Asked June 12, 2024, 1:21 AM EDT
Can someone confirm if these are wooly aphids on my newly-planted western crabapple trees? I have no idea where they came from (I've notified the nursery I bought the trees from), but from what I've been reading, they attack fir trees in Oregon, not crabapples. I'm worried it's going to spread to our other yard trees, some of which are pine trees - is there a way to stop it quickly?
Multnomah County Oregon
Expert Response
Hi Robyn and thanks for your question and great pictures of your Woolly Apple Aphids. I'll attach an article with more than you ever wanted to know about the pest, but briefly:
-with this small of an infestation you can probably wipe it away
-natural predators such as lady beetles, syrphid fly larvae, green lacewings, Deraeocoris brevis, Aphelinus mali and the European earwig will move in to control them
-you may not see these predators as they often consume the whole colony, earwigs working especially well but at night
-other hosts include the American elm, hawthorn, Mountain ash and cotoneaster. It would be hard to remove all of these from your neighborhood!
-these are not the same aphids that attack evergreen trees
-if you spray an insecticide, it will most likely not affect the aphids due to the waxy white coating, but will kill any beneficial insects coming in to help eat them
- the aphids can fly so can come from anywhere
I'll end with telling you we had a terrible outbreak on our Melrose apple tree one year, but didn't know what they were so did nothing. This was about 15 years ago and they disappeared and have never been back.
https://treefruit.wsu.edu/crop-protection/opm/woolly-apple-aphid/
A bigger concern is the blackened area around the base of your tree, the white powder out at the drip line and the depth it looks like your tree was planted. If any (or all) of these are stressing your tree, you will have other problems as the year goes on.
Keep us posted and good luck with the aphids.
-with this small of an infestation you can probably wipe it away
-natural predators such as lady beetles, syrphid fly larvae, green lacewings, Deraeocoris brevis, Aphelinus mali and the European earwig will move in to control them
-you may not see these predators as they often consume the whole colony, earwigs working especially well but at night
-other hosts include the American elm, hawthorn, Mountain ash and cotoneaster. It would be hard to remove all of these from your neighborhood!
-these are not the same aphids that attack evergreen trees
-if you spray an insecticide, it will most likely not affect the aphids due to the waxy white coating, but will kill any beneficial insects coming in to help eat them
- the aphids can fly so can come from anywhere
I'll end with telling you we had a terrible outbreak on our Melrose apple tree one year, but didn't know what they were so did nothing. This was about 15 years ago and they disappeared and have never been back.
https://treefruit.wsu.edu/crop-protection/opm/woolly-apple-aphid/
A bigger concern is the blackened area around the base of your tree, the white powder out at the drip line and the depth it looks like your tree was planted. If any (or all) of these are stressing your tree, you will have other problems as the year goes on.
Keep us posted and good luck with the aphids.
