Can anyone help me identify this tree? I’m in Santa Fe, NM (high desert climate) - but this is obviously landscaped and irrigated, and it may not be endemic.
In the second photo, you’ll see that there’s white growth on the branches. It’s dry and powdery, brushes off easily. It’s all over the tree, but the tree appears to be thriving. Any idea what it is, and whether I should be worried about it?
https://drive.google.com/drive/folders/0B0zTRKnct3JXNktPVjRPMXlrb1E
It looks like wooly aphids on a crabapple.
Malus ioensis, or the prairie crabapple, is endemic a few states east.
Having looked at some images and videos, it certainly looks like woolly aphids. But I just checked, and there’s nothing living on my branches. Do they die and leave the white stuff behind?
They are the white stuff - it’s a mass of waxy filamentous material that they produce for their own protection.
Yes, I understand that. But my point is, when they are alive on the branches, they look like this:
That’s not what I’m seeing on my branches. There are no living creatures there, just inert white stuff that flakes off when you touch it. Does that mean I have dead woolly aphids?
It’s possible you have dead aphids there - they are mortal animals - and not necessarily predated upon by many things due to their unpleasant fluffy waxiness - but unless you’ve sprayed or something else has killed them, I’d be surprised if there aren’t also some living specimens amongst the white masses in the photo.
Could we have a closer-up picture of the branch with the white stuff please?
If you go to the same link above, I have uploaded two more pics.
I’m sure you’re right now - woolly aphids. I was confused at first, because on much of the tree I think the aphids probably died a while ago, so no bug bodies or movement were visible - just amorphous crumbly white stuff. But I have now scrutinized the tree more carefully, and I found a few spots (as in the new photos) where there are clearly living bugs. Also the “honeydew” sticky deposit.
Treatment options?
From what I have researched, there is no need to panic. The tree is thriving, no leaf damage yet. And the consensus seems to be that spraying aggressively with a toxic insecticide may do more harm than good, because the wool protects the aphids, so a spray may end up killing off more of their natural predators.
So my plan is to spray with mild insecticidal soap to get them under control; and for a long term solution to apply Imidacloprid systemically, i.e. at the foot of the tree to be taken up through the roots. The systemic approach apparently may takes months, but it’s specific to aphids or other bugs that are dining on the tree, whereas it will do less harm to predators that are eating other bugs.
Go with the insecticidal soap: cheap, effective and eco-friendly. I’d stay away from the systemic stuff if you ever wish to use the fruit.
Thanks all for the advice.
One local person suggested using a water jet from a hose to physically dislodge as much of the material from the branches, before applying a soap spray. I can’t find any reference to this online, so I’m not sure if it’s a good idea. Any thoughts?
Plain water spray works on a lot of insect pests, but you have to repeat for awhile.