What do you mean 'concentrated Spruzit'?
Did you not dilute it with water (like you're supposed to do) at all or just not enough?
These spots could be from the Spruzit 'burning' the plant due to a higher concentration than it's supposed to be.
Even if Spruzit is a biological insecticide, if used wrong, it can harm plants, probably what happened here.
Also only try to spray something on your plant, when theres not too much light shining on it, since this can create burn spots on it (but it doesn't look like this is the case here).
I'd recommend to try to wash of the leafs carefully and dry them with a slow running fan.
After that keep an eye on it, just in case there is a fungus on the leafs. If this is the case you should see it becoming worse over the next few days.
Feel free to contact me, if that happens. I hope I could help.
Cheers