Imidacloprid - Suitable to eradicate Spider Mites?

[rbarata]

I'm not sure if I have them in my den.

I can see fine webs, leaves with a strange pattern that I thought it was dust but won't come off with a wet cloth.
But I don't see any bugs, which I think are red. Cleaning a leave, upper and lower sides and there's nothing visible.
I'll post a photo later.
I was thinking about spraying it tomorrow with Imidacloprid but I've read is not effective for this pest.

Thank you