Originally Posted by october

Hello eeiko321.....Yes, it is almost definitely scale from the pics you showed. I battled scale for 3 years on my bonsai and finally won the battle a couple of years back. They are one of the worst things that can happen to trees.

I have read hundreds of articles and did 3 years of research into this pest.

I would like to warn you that this can become a real serious issue. Scale is one of the hardest pests to eradicate, sometimes, impossible. Scale nests on every part of the tree. How it works is, the babies are born with legs..they crawl around and find a nice spot to settle down. Then they lose their legs and begin sucking on the spot they are in. As they feed. They keep secreting a fluid that keeps building up a protective shell. If you have ever seen oyster shell scale, it is the worst kind, they look like little oysters on your trees and are immune to most pesticides because of this protective armor like shell. Scale have a peircing structure that they stick into the tree to suck the juice from it. You'll notice that they are so stuck on the tree that if you try to take them off, they may actually tear in half and leave part of themselves on the tree. Live scale smear and bleed, if they are dead, they just flake off.

In time, the adults lay their eggs underneath the protective shell. So even if you pic them off, you must spray a form of hoticultural oil or a systemic in the soil to kill the remaining eggs. Also, they tend to keep coming back. You would need to pick off all the scale you see, then spray...then wait about 4 weeks, pick all of them off again, then spray again. If they persist, you can add a systemic instead of the spray during the 4 week cycle. However, since this is a garden tree. I don't know if I would use a systemic. Don't want it getting into other root systems of near by trees.

What is happening now with your tree is a bad infestation. In the beginning phases, the scale migrate on the bark, crevaces and branches and undersides of leaves. As the infestation grows, they begin making there way to the tops of the leave along the middle vein of the leaf. They basically suck the tree until its dead.

I also must be the bearer of more bad news. Scale is extremely invasive and spreading, they will jump from tree to tree until they get almost every one. However, they tend to go for fruiting and flowering trees first. Sometimes, they will leave the others alone.

There are many kinds of scale, juniper white scale, oyster shell scale, soft brown. Yours don't look like oyster, however I would need a close up pick.

Depending on how big and how expensive the tree is. Cutting it down may be a good option to consider. If it is extremely infested. However, if it is not a big tree, try using a horticultural oil spray on it. However, you must read the label. These oils cannot be used in extreme cold or extreme heat. Also, read the label for species that it should not be used on. If the scale is on the tops of the leaves, you have a full on infestation. Also, if it is cold in your area and the scale are that abundant, that is even a worse infestation.

You will need to check all, I repeat, all your trees. Bonsai, landscape everthing. Normally the first step when scale is discovered is to isolate it immediately from all other plants. If no other tree in your home or landscape have it, getting rid of it might be a good option I wish you luck

Rob.