Can someone help with these pests?

Unnilnonium

Seedling
Messages
5
Reaction score
3
Location
Maryland, USA
These little white nits are infesting my stock. There doesn't seem to be a species they can't infest other than pines and cedars. I have tried Neem, Seven, diatomaceous earth suspension, and some other insecticides that damaged some trees. I resort to scrubbing them off with an old toothbrushand a piece of wire, but typically, they come back. I am fairly sure they are only egg cases - nits, but I rarely see anything accompanying them other than occasionally one or two squishy scale bugs, and there are dozens of nits on infected trees.

I pulled this hornbeam from the wild several years ago, and this spring they appeared (or perhaps last fall, and I missed them) for the first time on this tree. They are about one mm long. I'm sure there are many posts on these - I did look for one, but I don't know what to call them. Anyone
know what to do?
Hornbeam Crop.jpgHornbeam Trunk Detail.jpgHornbeam Branch Crop.jpg
 

sorce

Nonsense Rascal
Messages
32,908
Reaction score
45,579
Location
Berwyn, Il
USDA Zone
6.2
Welcome to Crazy!

I believe these are soil pests that transition while up the tree.

Removing their preffered habitat, rock hides and leaf litter, should inhibit their reproduction.

Moss em.

Sorce
 

Unnilnonium

Seedling
Messages
5
Reaction score
3
Location
Maryland, USA
Oh, so maybe they're pupae or empty chrysalises. Some other trees that are infected do have moss covering the soil. Now I may try to repot with sterilized soil and try to reintroduce mycorrhizae - thanks for the idea! Although hornbeams are sensitive to changes in the soil... burr....
 

sorce

Nonsense Rascal
Messages
32,908
Reaction score
45,579
Location
Berwyn, Il
USDA Zone
6.2
IMO....

These things do no harm to a tree, contrary, their presence will invite predators that will also eat things that are actually bad.

Spray not.

Sorce
 

Unnilnonium

Seedling
Messages
5
Reaction score
3
Location
Maryland, USA
Ok thanks! I will just keep removing them mechanically if I need to. Otherwise I'll leave them alone.
 

Unnilnonium

Seedling
Messages
5
Reaction score
3
Location
Maryland, USA
So, an update.... These little #@&#**'s went buck wild in the fall and reproduced like crazy. I sure do hope they're harmless, although they may soon be in such numbers as to suffocate the tree outright, harmless or not. I scraped these casings off of the bark, and hopefully after repotting in the spring, something may happen - or, rather, not happen. As I have said before, I have tried many different insecticides on these pests on different trees, and some of those insecticides ended up damaging some of the trees - see the original post for a partial list of those I've tried. I am leery about applying pesticides to hornbeams since they are so sensitive. There is a new development - one of the pictures (picture #7) shows a swelling of one of the twigs which may be related, or may not - we did have our cicada outbreak this summer and although my trees were protected, some may have gotten through my defenses. Also, one of the wounds where a branch was removed is beginning to look rather suspicious (picture #6). So, given the developments, I am bringing it to the community again for reassessment - if anyone has any answers, or is willing to reaffirm the prognosis that they are harmless, it would be greatly appreciated! Thank you all! You have been very helpful.Hornbeam Infestation Worsening 6.jpgHornbeam Infestation Worsening 1.jpgHornbeam Infestation Worsening 2.jpgHornbeam Infestation Worsening 3.jpgHornbeam Infestation Worsening 4.jpgHornbeam Infestation Worsening 5.jpgHornbeam Branch Swelling.jpg
 
Last edited:
Top Bottom