Gloomy Scale :(

[Dabbler]

I've been dealing with gloomy scale on this maple for a couple years now. While the tree doesn't stop growing like mad and doesn't seem to be affected it, it's really annoying to think I got all of them to see they it comes back in a few months Anyone have any advice as it has never gotten onto any of my other tree's.

 

[Wires_Guy_wires]

There are two types of bugs I use systemics for:
Scale aphids and wooly aphids.
Contact insecticides just don't work on them here, and I don't like spraying poison if it doesn't work.

Two consecutive treatments, 3 weeks apart, kills them all.

I'm combining lambda-cyhalothrin and acetamiprid in a single mixture and it works. Acetamiprid is being banned here though, so you might want to look at something else.